TJ Frame Swap: Putting a 2006 Frame Under A 1998 Sahara

Quick Links:

Summary Post
Cost & Time Details
Differences Between '98 & '06 Frames
Preparing Your Replacement Frame
Tips, Tricks, & What I Would Have Done Differently
Preparing To Separate Body From Frame
Disconnecting Body From Frame
Swapping Components From Old Frame to New Frame
Tub Rust Repair & Prep For Mounting To New Frame
Mounting Body To New Frame
Next Steps
First Startup & More
My Final Steps

Overview

First, I would like to thank the following forum members: @Chris, @Goatman, @GASnBRASS, @Kevin Bright, @TJ4Jim, and @RangerRick for your excellent advice, for answering my questions, and providing helpful links to the TJ FSMs and parts manuals. Seriously, a heartfelt thanks. I wasn't expecting the level of support, camaraderie, and expertise that you all provided. My Jeep is back on the road due to your help.

I have already completed this swap, and I am doing this thread after the fact.

This Jeep is the first new car I've ever bought for myself. Moss green Sahara with a 5 speed. I placed the order in November of 1997, took delivery on 10 Jan 1998. The price out the door, including tax, title, and tags was $21,133 with both tops, A/C, Lockable Trunk, 30" Wheels/Tires, Cruise Control. As well as being used for camping/hiking/kayaking/sailing duties, it was also my daily driver until April of 2012. My daughter and my son, both millenials, have learned to drive on this Jeep and are both now Jeep enthusiasts (and manual shift enthusiasts). My son now drives it to high school every day, just as his older sister has done before she headed out to university.

July of 2019, failed the VA state safety inspection for rust and some other items.




After some thought and research, I determined I would replace the frame rather than repair it or purchase a new Jeep. Further research showed that I would need to do this myself-it was cost prohibitive to have a shop perform the work.

And it was a lot of work. I watched a video on YouTube showing 3 professional mechanics performing a similar swap in 5 hours. I thought to myself that I could do this in about 80 hours across 12 days, for about $2000.00. I spent more than 90 days searching for a frame. The swap actually ended up taking 173 hours across 2 months, with the final cost at $4712.25. Within those two months, I also had 3 solid weeks of business travel (22 days in total), Thanksgiving and Christmas Holidays, and of course my typical work.

Knowing what I know now, I believe I could do this much quicker, and possibly for less money (debatable). The only way 3 guys could complete this swap in 5 hours is by having a seriously complete and Jeep-centric parts stock immediately at hand, cutting all of the bolts with a power saw, using a frame from the same series/year TJ that is prepped and ready to go, having a large work area with at least two lifts, having replacements for all of the previously cut bolts on hand, and having performed the same task multiple times before.

Hopefully my write up and cost details will help others save time and money when the need for a frame swap arrives. I thought I would be able to take more pics, but most of the time it was only me working alone and I was trying to get it done, if I'm being honest. I couldn't spend time on too many photos. Still, I took some and I will add them to the write up where appropriate. The attached spreadsheet has all of my costs, a link to the vendor where appropriate, and part numbers and other pertinent information.

SUMMARY:

-1998 Jeep TJ Sahara. I am the original owner, ordered in Nov '97, delivered Jan '98
-266,366 miles at beginning of the swap
-Original clutch-time to replace
-Time to replace rear main seal
-July of 2019, failed VA State Safety Inspection due to frame rust, manifold leak, steering box leak
-Time to replace exhaust manifold gasket to fix the leak (or so I thought)
-Early Nov, located a suitable frame in WV, about 4 hours drive from my home
-Began swap on 19 November 2019
-Finished swap on 17 January 2020
-Frame hunt took more than 90 days. Most frames available were projects in their own right, and I took my time to find the right frame for me.

In the attached spreadsheet, if you download it and choose enable editing mode, you can sort the categories with the drop down box at the top. Also, at the bottom of the data, you can change the categories to see the cost differences as well by category. The suppliers are hyperlinked to the parts where available.

Swap Details:

Total time working on the swap, including online research, clutch replacement, rear main seal replacement, body mount rust repair: 173 hours. Clutch replacement took 9 hours, rear main seal took 3, body mount rust repair took 9 hours, including painting and rust proofing.

Total cost, including frame, parts, tools, local service, shop supplies: $4712.25

Costs break down:
Frame: $1656.10
Parts: $2226.29
Tools: $515.26
Supplies: $100.60
Service: $214.00

Differences Between 1998 Frame and 2006 Frame:

1. Steering box and steering box mount: The '98 uses the Saginaw steering box; the '06 uses a ZF steering box. The frame mounts are different and you will have to modify the '06 frame in order to mount the Saginaw box: there is a write up about it on this forum. If you use the ZF box (I did), you will need to change your power steering lines from the '98 to the '06 lines, as well as change the lower intermediate steering shaft from the '98 to the '06 model. The '98 shaft is 27 5/16" long, and the '06 shaft is 29 5/8" long. The part number is Mopar 55315044AA. I bought a new one from an ebayer as I didn't have time to find a used one and they weren't at all available used, it seemed. I paid $174 delivered, which was a bargain compared to $300-plus prices I was seeing.


2. Transmission skid plate: skid plate mounts are different between the two and you will need the stock '06 skid plate or an aftermarket skid plate. Additionally, the transmission-to-skid plate mounts are different. I used the stock '06 skid plate and my stock '98 trans-to-skid plate mounts. I marked and drilled new holes for the transmission-to-skid plate mounts, painted and rust-proofed the holes, reassembled, and this works fine. The difference in bolt location is just about 1/2" rearward and 1/2" toward the driver's side. It's likely that a transmission mount from an '06 transmission would mount perfectly to the '98 trans, thus allowing you to use the '06 stock trans-skid plate mounting locations with no mods, but I didn't take this path so I don't know.


3. Fuel and brake line clip mounting holes: There are plastic clips along the frame that hold the brake and fuel lines. The combo fuel/brake/electrical clips can still be found on ebay. They are black with 5 multi-sized clips and you need five. I found the single size white brake line clips from Mopar Parts Giant-you need seven. These 12 items cost me $77.80. They press into the pre-drilled holes in the chassis. Note where these holes are located on your existing '98 chassis. On the '06 chassis, these holes are too large for the black multi-size clips. You will need to drill and paint a 3/16" hole near the existing holes to mount the new clips. You will need to use a hair dryer on the clip mount pins, or "trees", to heat and soften them so they will slide easily into your 3/16" holes. The single size white brake line clips will work in the provided holes with the exception of the one on the inboard side of the frame nearest driver's side tire. This hole is too low on the frame and you will need to drill a new one once you have the brakes reattached to the master cylinder.


4. Grounding location: On the '98 frame, there is a grounding point for a ground cable from the ignition coil to the frame on the passenger side near the shock tower. This grounding point is not provided on the '06 frame. I used the bolt holding the front passenger side soft brake line to the frame for this ground location.

Other than these stated differences, I didn't find anything else that would not work between the '98 and '06 frames.

Preparing your replacement frame:

I was fortunate in that I found a frame that was pulled from a low mileage 2006 flood victim from Florida. The engine mounts were for the 4.0 and included the stock trans skidplate and the ZF steering box with mounting bolts. Additionally, the frame and skid plate was cleaned, rust-proofed, and painted by the seller, and the cost reflects this. You will need to perform these actions if you cannot find a frame like this or are trying to keep the costs down.
Additional work required: on the bottom of the frame I drilled 5/8" drain holes 4.75" ahead of the rear control arm mounts using a step drill bit. I then cleaned, primed, and painted these holes. Photos below show the holes before I cleaned/prepped/painted said holes.

HOLE I DRILLED BEFORE REAR CONTROL ARM MOUNT:

There is a similarly sized set of holes behind the front control arm mounts, and I measured the hole diameter and distance behind the control arm mounts to arrive at the location and hole diameter for the rear drain holes. I spent some time on these holes at the front as well-they have threaded inserts for something that I am not using, and I cleaned and rust-proofed these inserts.

FACTORY THREADED HOLE BEHIND FORWARD CONTROL ARM MOUNT:

I used Eastwood interior frame paint (black) with the long application tube to paint the interior of the frame in its entirety.
If you are planning to use your Saginaw steering box, now is the time to alter your frame to accept the mount. If you are going to use the ZF box, this is the time to make sure you have the box, mounting bolts, and power steering hoses for an '06 TJ. The hoses will work with your '98 steering pump. However, you will need ATF+4 power steering fluid.
Finally, I installed all new upper coil spring isolators and bump stops on the '06 frame. I installed the lower isolators on coil spring mounts on the front and rear axles.

My List of Indispensable Tools:

TJ Factory Service Manuals (FSM) & Technical Documentation
Max Jaxx hydraulic lift in my garage. Very fortunate to have this.
Fuel line wrench.
Tire dollies-these are a must.
Medium and large pry bars-I had to use these to pry the skid plate off the '98 frame, and to help move and adjust the suspension and motor during reassembly.
Step drill bit, 7/8 up to 1 3/8-I used it to drill new drain holes in the '06 frame as well as drill skid plate bolt access holes in the '98 frame for Liquid Wrench application, and to drill drain holes in the torque boxes on the body.

Tubing bender-I used it to help adjust the replacement brake and fuel lines as well as adjust the supply power steering line-it was interfering with the pitman arm movement.
Milwaukee cordless impact drill.
Torque wrenches-you will need large and small torque wrenches. The largest torque is required on the control arm mounting bolts-130 lb/ft; smallest was 15 lb/ft. Nothing else is close to 130 lb/ft, except the flywheel mounting bolts at 106 lb/ft.
Liquid Wrench.
Engine hoist or crane, as well as heavy duty ratchet straps. I used 6 to attach the engine/transmission/transfer case to the crane hook.
Head-mounted light for good visibility.
Engine stand-used when I replaced the rear main seal. I definitely recommend this method rather than replacement from under the Jeep.
Pipe extension for your breaker bars.
Ziploc bags and permanent marker/sharpies in dark colors-I used these to bag and tag all bolts and nuts. I also wrote on both sides of the bags in case the words were smudged or were gone. I kept all of these in a box out of the way.
Paint pens in multiple colors to color code your vacuum and electrical connections as well as to mark bolts as being torqued during final assembly.
Wooden chocks for all 4 wheels-you will have your brakes disconnected for much of this project.
Oil/fuel absorption sand.
Cable ties. You will be cutting a lot of cable ties and some will be system-specific. I could not find any similar replacements, so I improvised as best I could.

Since I only have two tool bags, I set up a tool table with all my tools laid out so I could easily know where everything was, and at the end of each day I put it all back in the same spot.


Important note on hand tools: I only had 3/8" drive C3 tools prior to this swap. C3= Cheap Chinese Crap. I broke quite a few sockets, a ratchet drive, and 2 breaker bars-one of these nearly caused me serious injury when it failed. I upgraded to 1/2" drive tools and very heavy duty breaker bars, and this was much better and safer.

Tips, tricks, and what I would have done differently:

1. When you remove the gear shift knob, heat up the gear pattern cap section with a hair dryer for about 5 minutes. Take a slim flat screw driver and pop the gear pattern cap out. You will not damage your gear shift knob with this method. You will need a 15 mm socket to remove the nut, and then you will also need to unscrew the knob itself.

2. I cut my parking brake cables. This was a mistake. Do this only if you absolutely must. I should have used liquid wrench on the bracket where these mount from the rear drums. Then I should have used a twisting force to free them from the bracket-they were severely rusted. Finally, I should have used a worm drive pipe clamp to pull in the clips from the mounts so that I could remove the cables from the bracket with no damage.

3. Take plenty of photos prior to disassembly. You will not be able to recall how everything goes back together. Where does that differential vent tube mount? How does that fuel line route? Where do those vacuum tubes connect? How about that throttle body spring? Etc.

4. Use the FSMs to get the torque specs, torque order, and other crucial information. On reassembly, where red or blue thread-locker is not required, use anti-seize lube. I went through more than 5 tubes of anti-seize.

5. Use Evapo Rust to clean bolts, nuts, small parts, and even some larger parts. I used small plastic solo cups with the description of the bolts/parts written on the cup to keep track of parts. Sometimes it took 48 hours to get the rust off with Evapo Rust-still it worked very well.

6. I should have ordered the control arm mounting bolts at the very beginning. I tried to reuse as many parts and bolts as possible. If your Jeep is as rusted as mine was, then you will break some bolts and damage some parts.

7. I should have sourced a trans-to-skid-plate mount from an '06, mounted it to my '98 trans, and then attempted to utilize the stock mounts on the '06 trans skid plate.

8. During engine remounting on the new frame, it is much easier if you have the oil filter and starter removed from the engine block.

9. I did not disassemble my axle/suspensions when moving from the '98 frame to the '06. During reassembly to the new frame, it is much easier and faster if you loosely attach your traction bars to the frame prior to attaching your control arms to the mounts.

10. Use dielectric grease for all electrical connections and ground connections.

11. Remove the inner gear shift boot prior to removal of the body from the frame.

12. Bag and tag all mounting hardware, write on both sides of the bag with a permanent marker, and keep these bags in a separate box in a good location. I used ziplock snack bags and a permanent blue sharpie marker.

Preparing for the body to be separated from the frame:

1. I used Liquid Wrench on every bolt and nut, every night I was home, throughout the swap, beginning 2 weeks ahead of starting the project and continuing right up to the point I was ready to unite the body to the new frame. I went through about 5 cans. This dramatically helped with bolt removal-in some cases I was certain that the bolt or nut was going to be a loss or a nightmare; instead I was surprised at the successful removal, attributable to the use of LW. I missed the radiator mounting bolts as well as the radiator shroud mounting bolts, and this caused me grief right away. Be sure you are prepping these particular bolts.

2. The night before I began the body/frame separation, I removed as much weight from the body as possible: doors, spare tire, top, rear seat, any additional cargo or items.

3. I removed the center console.

4. I drained the engine oil, coolant, power steering fluid, and brake fluid-as much as possible, anyway. Be prepared for random drips, drops, and splashes as you move items around.

5. Remove the battery and put out of the way.

Have A Plan-My Approach to This Project:

I recommend you write down your plan for the actual order you will swap each component/system. My initial plan is in my first post on this topic on this forum. The list below is how I actually worked through the swap and what, if anything, I would have done differently. Note I have a 2 car garage. Some steps have additional details posted later in this thread, such as the clutch replacement, disconnect of systems between the body and frame, and body to frame re-connection. Bag and tag all mounting hardware, even if you think you won't need it later.

1. Fuel-I ran the fuel level down to the white line on the fuel gauge. This was perfect-low weight and still enough fuel for the start after the swap.
2. Liquid Wrench all bolts every night for two weeks prior to starting. This worked well, except I neglected the radiator and shroud bolts: a time-consuming mistake.
3. Drain engine oil, coolant, brake, and steering fluids. I did not remove the refrigerant.
4. Reduce body weight: remove doors, top, spare tire, rear seat, anything else I would not be able to reach once the body was up on the lift. I also removed the center console and gear shift knob. Inexplicably, I did not remove the inner gear shift boot, which was subsequently destroyed and I had to replace it. Suggest you remove this item, and you will need to pry it off after removing the 4 screws. Remove side steps or anything that may get in the way of access to the body mounts.

5. Lift and put the Jeep on wheel dollies. Chocks for brakes.


6. Remove battery.
7. Disconnect frame-to-body systems and unbolt all body mounts. Remove front and rear bumpers, and bag and tag all mounting hardware. *This step has a detailed description of what/where/how here*.
8. Raise body off the frame.
9. Roll chassis to the open bay in the garage.

10. Disconnect the rearmost O2 sensor electrical connection, exhaust at the cat, fuel lines from the manifold and the fuel tank. Set all aside.
11. Replace the exhaust/intake manifold gasket. Note that, when reassembling, there is a specific order in which these bolts must be torqued-I strongly recommend you consult the FSM (field service manual) so that you do this correctly (if this is part of your swap). I should, at this point, have removed and inspected the header; instead I assumed the manifold leak was the gasket, and I only moved the header just out of the way (I disconnected the exhaust at the cat instead of at the downpipe). The header has a crack, and I will be replacing the header/headpipe and manifold gasket this weekend.
12. Disconnect all electrical connections from transmission rearward to the fuel tank. Tie these up out of your way after photographing the routing.
13. Remove front and rear prop-shafts and set aside. You will need a 1/4" drive, six pointed 8mm or 5/16" socket for the prop-shaft bolts. Not much room to maneuver.
14. Replace the clutch. *This is its own saga and has a special section in this thread.*

Once I was at this point, I moved the '98 frame to make room for the '06 frame, and then I took the '98 frame off of the wheel dollies. I then lowered the Jeep body onto the wheel dollies, rolled the body away from the center of the bay in which it was lifted, dismounted and stowed the inboard lift post, and moved the new frame into the newly available space. I then began moving components from the old frame to the new frame.

15. Pull engine/trans/t-fer case from the '98 chassis and move to the side, including the steering box. I used a pickle fork to disconnect the Pittman arm from the tie rod. In retrospect, I should have done this at step 14 and replaced the clutch with the engine out of the frame.

For these next steps, I strongly recommend some helping hands OR that you think through how you will safely accomplish these tasks if you are working alone. I used two additional people for these next steps. I did not have the ability or tools and props necessary to complete these alone. Also, I did not need a spring compressor here.

16. Remove and set aside the fuel tank. Liquid Wrench is your friend here. No way these nuts come off without a daily dousing of the LW. You will likely need to replace all of the mounting nuts here.
17. Remove shocks at all 4 corners and discard. Shout out to the LW. If you are not replacing your shocks, set them aside, bag and tag all hardware.
18. Disconnect all hard and soft brake lines. If you feel you will be able to save and reuse these, set them aside. My hard lines were horribly rusted and my soft lines had never been replaced. I replaced them all and didn't bother trying to save these. Bag and tag all bolts or nuts.
19. Prop up the rear of the '06 Frame high enough to accept the completely assembled rear suspension and coils.
20. Have items ready so you can prop up the rear of the '98 frame high enough that you can move the completely assembled rear suspension from under the frame.
21. Remove the control arm bolts from the frame and axle mount locations, upper and lower. I broke two bolts that were rusted beyond recognition-all others came out. Knowing what I know now, I would have only removed the bolts from the control arm axle mounts (I replaced all of my control arms with new units). I would have ordered the complete set of control arm bolts/nuts prior to beginning this project and I would not have spent the time to try and remove and reuse the control arm bolts. Bag and tag all hardware you plan to reuse.
22. Remove the track bar mount. Bag and tag hardware.

At this point, check the FSM to determine which of the mounting hardware needs thread locker. Choose a paint pen to mark these as you are installing them: blue for blue thread locker, red for red thread locker. Any hardware that does not need thread locker, apply plenty of anti-seize lube and don't be stingy-I went through more than 5 tubes of anti-seize lube.. Hardware requiring thread locker will need to be pulled back out, one at a time, thread locker applied, then put back in and torqued to spec. That time is not now. You will torque these to spec only after there is sufficient weight on the suspension. Refer to the FSM for details.

23. Roll rear suspension over to the '06 frame. You will need chocks, in front of and behind the front tires, and something to prop up the front of the differential so that you can line up all of your mounts. Install new coil spring isolators on the axle and then the coil springs. At first, hand thread very loosely all bolts and nuts. Make sure your control arms are correctly oriented. Begin with the track bar mount, then the lower control arm mounts, then the upper control arm mounts, then your shocks. Tighten all bolts and nuts until they are *just* tight. Do not torque anything to spec. This will be done in stages after there is enough weight on the suspension.
24. Prop up the front of the '06 frame high enough to accept the completely assembled front suspension and coils. Note that the front of the frame is substantially heavier than the rear.
25. Lower the rear of the '98 frame to the ground, and be ready to prop up the front of the '98 frame high enough so that you can move the completely assembled front suspension from under the frame. Note that the front of the frame is substantially heavier than the rear.
26. By this time, I had a complete set of control arm bolts that I bought off ebay. I removed the control arm bolts from the axle mounts only, leaving the upper and lower control arms on the old frame. Bag and tag any hardware you plan to reuse.
27. Remove the front track bar mount. Bag and tag hardware.
28. Roll the front suspension over to the '06 frame. Chocks, in front of and behind the front tires, and something to prop up the diff so you can line up the mounts. Install coil spring isolators and coil springs. Hand thread very loosely all bolts and nuts. Begin with the track bar mount, then the upper control arms, then the lower control arms. Next, shocks. Tighten all bolts and nuts until they are *just* tight. Do not torque anything to spec. This will be done in stages after there is enough weight on the suspension.
29. Check the old frame for any parts/bolts/nuts/connectors that you may want or need to keep. Mostly this will be the engine mounts unless you are using new mounts. Photograph anything you may need to reference later. Chuck the old frame-it is done.

At this point, I discarded the old frame, swept up and organized my work space, remounted the inboard lift post, put the Jeep body back on the lift and up in the air, and put the newly suspended Jeep frame back on the tire dollies for ease of mobility.

30. Prepare to install the engine/trans/t-fer case. Make sure the oil filter is removed and the starter is disconnected and out of the way. Make sure your engine mounts have been properly mounted to the frame and torqued to spec. You will need six grade 8.8 bolts, M12 1.75x40MM plus 6 M12 washers in order to mount the trans skidplate.
31. Mount the engine to the front engine mounts. This will take some trial and error on your part. Once mounted, support the rear of the engine so that the trans/t-fer case is high enough that you can mount the trans skid-plate to the frame. Re-install the starter and torque to spec.
32. Mount the skid-plate to the frame and tighten but do not torque to spec. You will need to lower the trans mounting bolts onto the skid-plate and mark where the bolts meet the skid-plate with a paint pen.
33. Dismount the skid-plate and drill new holes for the trans mounting bolts. I believe I used a 3/8" drill bit.
34. Remount and check the fit of the trans mount to the skid-plate. Adjust the holes as necessary using a rat tail file until the fit is good.
35. Dismount, clean, prime, and paint the trans mount holes in the skid-plate.
36. Remount the skid-plate to the frame, torque to spec, then mount the trans to the skid-plate, torque to spec. Re-torque the skid-plate-to-spec. I used anti-seize lube between the skid-plate and the frame, on the skid-plate mounting bolts, and on the trans mount bolts and nuts. I painted it with anti-seize.
37. Torque the engine-to-engine mount bolts to spec.
38. Install both front and rear prop shafts. Blue thread locker on these bolts, and the torque spec is quite low.
39. Install your steering box and torque to spec. I chose not to install the power steering lines at this time.
40. Perform an initial torque to spec on all suspension bits, control arms, track bars, shocks, and anything else installed on the '06 frame. Double check the FSM for requirements of thread locker, and be sure to use it. Be sure to use anti-seize everywhere else, with prejudice.

A great big whisky to be savored. Neat, with a few drops of distilled water. 16 year old Lagavulin for me. And Advil. Lots of Advil.

41. Time to mount the fuel tank and fuel tank skid-plate, black fuel and brake line multi-size clips, fuel line, fuel vapor return line, brake lines- soft and hard, and reconnect all electrical connections. Use dielectric grease after you have cleaned up any corroded electrical connections.
42. Reconnect the exhaust. The exhaust hanger mounted in front of the rear shocks will need to be adjusted to mount to the '06 frame as one of the mounting holes is off by about 1/4". I used a rat tail file to make the adjustment, then cleaned, primed, and painted the bigger hole. I also used a washer large enough to provide adequate support.

I drilled out the mount of the old filler-neck grounding strap-it was badly corroded, with just a short piece left. To this day I have no idea where the other end of that strap was connected-I found no connection points on the old '98 frame, nor anywhere on the body. I bolted a 20" AC Delco replacement strap onto the filler neck, bent the other end to an 86 degree angle, and mounted it between the body and the plastic insert around the fuel filler on one of the mounting screws. If anyone has any idea where it's supposed to go, please let me know.

Don't forget to cable tie everything back into place, use dielectric grease on all electrical connections, and ensure you use anti-seize on all brake line-to-frame mounting bolts and on any other connections which you weren't required to use thread locker.

Time to Prep The Body For Remounting:

Prior to reuniting body and frame, I had to address rust issues at the mounting points on the torque boxes. Specifically, the center mounting point on both sides, under the doors. The driver's side was still there, but was quite rusted. The passenger side was so rusted that I didn't need to unbolt that mount-it just stayed with the frame once I lifted off the body. All remaining mounts were in very good condition.

I am no welder. I had a buddy come and weld in new center mounts from Rust Repair Patch.

In preparation, I bolted one of the new mounts in place on the driver's side, measured the distance from the end of the new mount closest to the front of the frame to the center point of the floor drain plug. I then used that measurement for the placement of the new mount on both the driver and passenger side. Once that was recorded, I cut out the offending rusted areas from the torque boxes, prepped the raw metal with primer and paint, and also primed and painted the inside of the new mounts. After my buddy welded these in place,

I drilled 5/8" drain holes in the new mounts on either side of the mount location (I used the longest mounts available from the Rust Repair Patch website). Then I used the Eastwood Interior Frame paint inside each torque box to attempt to rustproof the interior of the torque boxes. I cleaned, primed, and painted the outside of the new mounts. Time will tell...

Other than these mounts, there was no additional rust. I was quite surprised by this, and very happy.

I replaced all of the radiator mounting bolts and mounting clips with matching hardware from the local hardware store. I replaced all of the shroud mounting screws with new hardware as well. Anti-seize lube all around.

I cleaned anything else under the Jeep that was dirty, tightened the nuts around the muffler and cat heat shields, put lithium grease on the transfer case shift linkage points, sanded and cleaned all grounding points and mounts, as well as the main positive battery connections, and that was it.

Time to reunite the body with the frame.

Reuniting Frame and Body Mounts:

You will need a second set of eyes for this, and a third would be even better.

This is a time-consuming process, requiring patience, preparation, caution, and extreme care. This is where the wheel dollies come into their own-in addition to giving you about 5" extra height under the frame, they also allow you the ability to make very small adjustments to the frame position in order to mate up all eleven of your body mount bolts.

Preparation: Put the gear shift into third gear. Tie your brake lines together and as close to the intake manifold as you can. Put your transfer case and both differential vent tubes down and out of the way so they don't get pinched between the frame and body. Tie your clutch slave cylinder up and out of the way. Make sure all of your electrical connections at the firewall are clear of being damaged. The frame should be centered under the body, and about 2-3" forward-as you are lowering the body, you want to ensure the top of the gear shift knob is centered in the gear shift opening of the body tub. If you have any mud flaps mounted to the body or any accessories that will impede your ability to lower the body or see the body mounts, remove those items at this point.

Lowering the body onto the frame: You want to do this very slowly. You want to check that everything is clear, and you need your second and third sets of eyes to be watching these items: 1. the fuel filler neck, ensuring that it is going into it's opening correctly; 2. gear shift lever to ensure it's clearing the opening; 3. the brake lines to ensure they are not being crushed as the body lowers; 4. the clutch slave cylinder to ensure that it is not being damaged; 5. Everything else above, below, and inside the engine compartment. Slow is your friend here. Once I had lowered the body close to the fuel filler neck, I would lower no more than 2 inches, stop, take a good look, make any adjustments to anything in the way, move the frame to clear anything else, and then do it again. First thing is to ensure your fuel filler clears and goes where it is supposed to go. Next, ensure the gear shift knob clears its opening. From here, you will check and align the frame every time you stop lowering the body. Finally, the body was less than 2" from the frame. I think this part alone felt like it took two days to complete but was closer to about 70 minutes. You don't want to lower the body completely onto the frame-you will need room to be able to make small adjustments to the frame position.

Quick Info About The Body mounts: You will not be torquing anything to spec at first. You are only going to get all of your bolts started with about 2-3 turns. This will give you the ability to position the frame in small increments to get all of your bolts started. Anti-seize lube is your friend here.

There are eleven body mounts, with two different sizes of bushing and bolts. There are six large bushings and 6 longer bolts. These mate up to the mid-body mounts in the torque boxes under the driver and passenger doors, three on each side. The remaining five are for the one in center/front of the radiator, two near the shock towers at the rear, and two at the rear near the outboard bumper mounts. (All four rear body mounts have floating nuts for your mounting bolts: they will move around to help you get the bolts started, and this is very helpful and crucial.) Stage these bolts and mounts at their respective locations, and press in the bushings, top and bottom, to their respective mount locations. Be sure that you have the correctly sized bolts with the correctly sized mounts.

The highest body mount locations are at the rear shock towers, followed by the two rearmost mounts, then the front near the radiator. The six at the mid body are the lowest.

Final Lowering Of The Body: I started by slowly lowering the body until there was about 1/8 of an inch between the body and the frame. Then I started the bolts at the two highest mount locations, near the rear shock towers. Next I started the two at the rearmost locations. CRUCIAL POINT: get the center mounts in the torque boxes under the doors on each side started next. Then get the one at the front started. Finally get the remaining 4 at the torque boxes started.

You will need to adjust the frame, little bits by little bits. You will need good light (headlight), and do keep your fingers clear when your helpers are adjusting the frame.

Once all of the bolts are started in all of the mounts, go to the front mount near the radiator, center the body mount and bolt, and then tighten with a ratchet until it's JUST tight. Next ensure the rearmost mounts are also centered but do not tighten them-you only want to make sure they are centered in the mount locations. Then tighten the mounts in the center of the torque boxes until they are JUST tight. Then go back and tighten the rearmost mounts until they are JUST tight. Then do the shock tower mounts and then the remaining torque box mounts until they are JUST tight. Now ensure the body is fully lowered onto the frame-the last 1/8"- and do another once over of all electrical, mechanical, fuel, and hydraulic systems to ensure nothing is being pinched between the frame and the body.

Finally, go back and torque the bolts down in the order and to the torque spec that is noted in the FSM.

Whisky, Advil, repeat.

Next Steps, In My Preferred Order:

Your preferred order may be different.
Lift Jeep off of the wheel dollies and return to terra.
Now that your suspension is fully loaded with engine and body weight, it's time to do another round of torquing your control arms, track bars, shocks, steering box mounts, brake line frame mounts, engine mounts, transmission mounts, and transmission skid plate mounts. Mark each bolt with a paint pen so that you know it's been checked and torqued twice.

1. Connect your brake lines to the proportioning cylinder. Follow the FSM.
2. Reconnect your 4wd shift linkage. You will need a second set of hands for this-one of you under the Jeep to hold the pivot bracket against the trans tunnel, and the other starting the bolts from inside the Jeep. Anti-seize lube.
3. Reconnect your parking brake cables to the parking brake adjuster and cable mount bracket. Anti-seize lube or cosmoline.
4. Install your '06 power steering lines. Follow the FSM. I thought about doing this prior to reuniting the body and frame, but the ZF box has both lines connected right at the top of the box: I didn't want to damage the body or the lines, and I didn't want the lines to interfere with the body mounting. Note that I had difficulty with the supply line interfering with my Pittman arm, and I had to pull it back off and use a tubing bender to adjust it accordingly. If you are using the Saginaw box, the lines mount to the steering box at a lower point and will not interfere with the body. Much easier to install these lines first.
5. Re-mount your A/C compressor and condenser. You will likely need new expansion nuts for the condenser mounts, and these are available at most hardware stores. Torque to spec.
6. Install lower intermediate steering shaft. Torque to spec. Double check this and torque again. This is very hard to complete with the radiator and fan shroud in place.
7. Install the radiator and fan shroud, and all coolant hoses. Don't forget the differential vent tube is secured with the radiator mount bolts. Torque to spec.
8. Remount air box and throttle body tube.
9. Install throttle cable through firewall and reconnect to throttle pedal.
10. Reconnect cruise control bowden cable to the throttle body.
11. Reconnect all vacuum lines and fuel return line.

Lunch.

12. Fill and bleed the brakes. Check all connections for leaks and tighten if necessary.
13. Bleed clutch slave cylinder, reinstall into transmission, torque to spec.
14. Fill power steering fluid. Check for leaks.
15. Fill and bleed coolant as much as possible.
16. Install new oil filter and fill with oil, as per FSM.
17. Reinstall front and rear bumpers and torque to spec.

18. Reconnect main electrical grounds to firewall ground points. Dielectric grease.
19. Reconnect all electrical connectors and connections, including to the ECU on the firewall and the main positive connection to the fender mounted PDU box. Torque to spec and use dielectric grease here. Refer to your previously taken photos for proper routing, and replace all cut/broken cable ties.
20. Reinstall battery.

First Startup And More:

Prior to startup, check engine oil level, coolant level, brake fluid level, PS fluid level, and check under the Jeep for signs of any leaks from any system. Address any issues.
Add fuel to the tank if you were empty.
Have someone standing by with a fire extinguisher.

Turn the key on for at least 5 seconds without engaging the starter, and check all of your gauges for normal activity. Turn the key off. Repeat this sequence 3 more times. This will help to ensure fuel is available at the throttle body for your initial startup. 5th time, attempt to start. My Jeep started up on the first try after about 5 seconds of turning over. Once the idle had smoothed out, I backed out of the garage and parked on the driveway, using wheel chocks as I did not have my parking brake cables installed yet. My driveway slopes down to the street, and I used this to help bleed the coolant, with the nose of the Jeep pointing up and running the engine with the radiator cap removed until operating temps had been reached and the thermostat had opened. I added coolant until it seemed full. Then I shut down the engine and allowed it to cool off for about 45 minutes. I then repeated this action twice more, letting it cool down between each session.
Next I carefully drove to the gas station for fuel. With a big stupid grin all over my face, all the way there and back. Man it felt great to be done!

Over the next week, I drove about 400 miles with no music playing, listening carefully for any new or strange noises. I performed a 3rd and final torque check, again using the paint pens to mark all the bolts. I also reinstalled the center console and the shift boots. I had a local service station install the parking brake cables and tell me if I would finally pass the VA state inspection. No-I still have the manifold leak. Once I install the new header, head-pipe, and manifold gasket, this should take care of that issue and I will try for the inspection. I will update this thread once I have the inspectors feedback.

Disconnecting Body From The Frame:

I used this video before I started. You should watch it as well, as it has some good info.

Here are the steps to disconnect the systems prior to lifting the body off the frame. Prior to doing any of this, take lots of pics of each step. Bag and tag any mounting hardware and small parts. Be sure to have your wheel chocks in place as you will no longer have any parking brakes.

1. Drain the engine oil, engine coolant, power steering fluid, and brake fluid.
2. Remove the battery.
3. Disconnect the 3 brake lines from the proportioning valve.
4. Disconnect the cruise control bowden cable from the throttle body. It just clips onto the throttle body, and it just pulls off, and will stay with the body.

5. Disconnect the throttle cable from the throttle pedal, and pull the cable through the firewall. This will stay with the engine and frame.
6. Disconnect the manifold vacuum lines-4 in total.
7. Remove the lower intermediate steering shaft from the upper intermediate steering shaft. The upper shaft is the one protruding from the firewall; the lower connects this shaft to the steering box mounted down at the front of the frame. You may need to disconnect the frame bracket, or loosen it, but I did not.
8. Disconnect the throttle body air tube from the air box mounted to the passenger side fender.
9. Remove the serpentine belt (only if you have A/C. If no A/C, leave the serpentine belt on).
10. Disconnect the clutch slave cylinder from the transmission. It will stay with the body.
11. Remove the gear shift knob. Heat up the gear pattern cap with a heat gun or hair drier until it's good and hot. Then use a slim flat screwdriver to pop the cap out without damaging the shift knob. Remove the nut and and unscrew the shift knob. Return the nut to the shift lever. Remove the outer shift boot. Remove the center console. Remove the inner shift boot by removing the four screws and then prying the shift boot off. Return the screws to the body so they are not misplaced.
12. Disconnect the electrical connections to the front foglights.
13. Disconnect the firewall grounding straps. There is a vent tube connected here as well, and it stays with the frame.
14. Pull back the carpet from the trans tunnel on the drivers side and unbolt the four bolts that are holding the 4WD shift linkage pivot bracket to the underside of the body. Bag and tag these bolts.
15. Disconnect the 4WD shift handle from the linkage underneath-it just pops loose with a quick pop of a screwdriver (see the video for this part).
16. Remove the fuel cap, and then remove the 8 screws from the plastic insert that hold the fuel filler neck to the plastic insert and the plastic insert to the Jeep body. Remove the insert, remove your fuel cap from the insert if it is attached, and then return the fuel cap to the fuel filler neck. There was half of a ground strap attached to the top of my fuel filler neck, but I have no idea to what it was connected.
17. Unbolt the fan shroud from the radiator and move it out of your way, over the fan blades. I did not remove the fan.
18. Remove the coolant hoses from the radiator and from the heater core inlets on the firewall.
19. Unbolt the radiator from the body and remove along with the fan shroud. Be sure the differential vent is disconnected.
20. Unbolt the condenser from the body (if you have A/C)-you can do this at the bottom of the condenser-two bolts. Once the lower bolts are loosened, you can lift the condenser straight up, but only a little bit, until you:
21. Unbolt the A/C compressor from the engine mounting bracket. This can now be tied to the grille support bar that runs from the top of the grille to the firewall.
22. Disconnect all electrical connections. There are two that go to the ECU mounted on the firewall on the passenger side. The plastic cover can be pulled off by squeezing the bottom inward and then pulling the cover up and off. Disconnect every electrical connector you see-most of these are plastic connectors. The exception is the main positive power connection to the passenger-side mounted fuse-box/relay box mounted to the inner fender. You will need to unbolt this. Take plenty of photos. There are some cable ties you will need to cut.
23. If you have a tow hitch, be sure to check that your tow hitch wiring harness is not cable tied to the frame.
24. Disconnect the two rear parking brake cables that go to the rear brakes. You do not need to disconnect the cable that connects to the parking brake handle inside the cab-it will stay with the body.
25. Remove the bolts from the eleven frame-to-body mounts.

Once all of these are disconnected or removed, put the transmission in 3rd gear, and slowly (slowly) begin lifting the body off the frame, double checking that you haven't missed anything.

Tigger09 said:

Great post.

Kinda related question, did you have the frame shipped and if so what did that cost?

Click to expand...

I had to pick up the frame. I rented a full-size truck and drove with my son about 8 hours round trip.

wraith1516 said:

is your state like michigan the frame is the titled part (meaning new/used frame vehicle must be titled with that frame)

Click to expand...

No, VA just uses the VIN stamped on the dash and also on the inside of the drivers side door jamb. I did search, and the old '98 frame did not have a VIN with it, and the '06 replacement frame did not have a VIN. I don't see how Michigan would know you had swapped the frame unless they require a VIN to be added to the frame.