Need help with lower control arm lengths

[Astala3]

Bit of back story to start. Last year I put all 8 adjustable control arms on a 2001 2.5 Tj. The jeep got upset climbing a hill one morning while driving to work at 4:30 am. That outburst left my engine block with a golf ball size hole in it and me in a cloud of smoke!

Naturally, I replaced that turd with a mint 2005 4.0 Rocky Mountain Edition. Rocky Mountain Editions came factory with Dana 44 and 3.73 gears! Love the new Jeep. 2 days after Christmas I drove off the interstate into a down tree. Never made it to deer camp! 2 days ago I finally finish the nightmare of the current insurance scams. got my jeep back!

Smashed the grille, hood, passenger fender. Scored all three of the replacements for $300. Also folded my passenger front rim and pushed my axle further under the tub. Passenger steering knuckle broke at the tie rod mount and bent the tie rod. The lower control arms folded like a tin can and their brackets on the axle need replaced. Upper control arms have folded also, less severely but toasted all the same.

Plan is to replace the lower brackets on the axle and move my adjustable front control arm over from the blown 2.5. problem is, I obviously do not have the factory control arm lengths to have as a starting reference to begin fine tuning the adj control arms.

I've already stripped the 4" lift from the old jeep that was on it when the adj control arms were installed and put it on the new Jeep. so the adj control arms were initially set and tuned for the 4" lift.

whats the general thought as far as simply transplanting the control arms? I understand that each jeep sits uniquely so fine tuning is unique to each ride also. thinking through it now, my best plan of action is to get them in there and measure for "axle squareness".

As for the steering components, planning to do a cross over steering upgrade.

4.10s in the 2.5 axle prevent me from just transplanting the entire front end. cant not have my 4x4! I live 30 minutes from Bantam jeep fest.

ultimately, I just need this thing on the road ASAP to get the enhanced inspection and R title work sorted out.

will be grabbing a Yj parts jeep in 2 weeks to pull the 8.8 rear and Cherokee Dana 30 front from it. gonna truss them both and slap them under the Rocky mountain Edition. why you ask? because its got an ARB air locker, 4.56 gears, and I'm only pay $200 for it! I'll make more than that in Yj scrap and selling the Dana 44. nearly pays for itself or costs me $ not to.

So, what's everyone's thoughts on the adjustable control arm situation, crossover steering and the Yj donor swap axles?

thanks guys

 

[TheBoogieman]

will be grabbing a Yj parts jeep in 2 weeks to pull the 8.8 rear and Cherokee Dana 30 front from it. gonna truss them both and slap them under the Rocky mountain Edition. why you ask? because its got an ARB air locker, 4.56 gears, and I'm only pay $200 for it! I'll make more than that in Yj scrap and selling the Dana 44. nearly pays for itself or costs me $ not to.

So, $225 for the Dana 44 and free shipping to Va?

 

[NashvilleTJ]

Bit of back story to start. Last year I put all 8 adjustable control arms on a 2001 2.5 Tj. The jeep got upset climbing a hill one morning while driving to work at 4:30 am. That outburst left my engine block with a golf ball size hole in it and me in a cloud of smoke!

Naturally, I replaced that turd with a mint 2005 4.0 Rocky Mountain Edition. Rocky Mountain Editions came factory with Dana 44 and 3.73 gears! Love the new Jeep. 2 days after Christmas I drove off the interstate into a down tree. Never made it to deer camp! 2 days ago I finally finish the nightmare of the current insurance scams. got my jeep back!

Smashed the grille, hood, passenger fender. Scored all three of the replacements for $300. Also folded my passenger front rim and pushed my axle further under the tub. Passenger steering knuckle broke at the tie rod mount and bent the tie rod. The lower control arms folded like a tin can and their brackets on the axle need replaced. Upper control arms have folded also, less severely but toasted all the same.

Plan is to replace the lower brackets on the axle and move my adjustable front control arm over from the blown 2.5. problem is, I obviously do not have the factory control arm lengths to have as a starting reference to begin fine tuning the adj control arms.

I've already stripped the 4" lift from the old jeep that was on it when the adj control arms were installed and put it on the new Jeep. so the adj control arms were initially set and tuned for the 4" lift.

whats the general thought as far as simply transplanting the control arms? I understand that each jeep sits uniquely so fine tuning is unique to each ride also. thinking through it now, my best plan of action is to get them in there and measure for "axle squareness".

As for the steering components, planning to do a cross over steering upgrade.

4.10s in the 2.5 axle prevent me from just transplanting the entire front end. cant not have my 4x4! I live 30 minutes from Bantam jeep fest.

ultimately, I just need this thing on the road ASAP to get the enhanced inspection and R title work sorted out.

will be grabbing a Yj parts jeep in 2 weeks to pull the 8.8 rear and Cherokee Dana 30 front from it. gonna truss them both and slap them under the Rocky mountain Edition. why you ask? because its got an ARB air locker, 4.56 gears, and I'm only pay $200 for it! I'll make more than that in Yj scrap and selling the Dana 44. nearly pays for itself or costs me $ not to.

So, what's everyone's thoughts on the adjustable control arm situation, crossover steering and the Yj donor swap axles?

thanks guys

Cross over steering is vey difficult to do correctly in the TJ - and impossible to do using the stock track bar. It will destroy the geometry, and cause bump steer. Crossover works in the YJ, because leaf springs.

If you need to fix / update the steering, stick with the inverted Y setup (the stock configuration). If you need the extra strength, go with the Currie Correctlink setup.

 

[Unique Username]

I wouldn’t consider cross over steering an upgrade. It’s different, but not better. I ran it for a few years and the only issues were the heim joints needed boots or consistent lube to remain silent and the hardware always needed snugged as the pinch nuts would back off. I would say the ZJ steering is a better upgrade in this situation.
If you want some general numbers, Clayton off-road has a bunch of measurements listed in the instructions listed on the control arms PDF listed for sale on the web site. Not sure how accurate they are, but it’s a source.
Best of luck with your project.

 

[Astala3]

Awesome. Thanks for those figures on the control arms. Those will be handy to have.

Crossover steering seems like it may induce other issues, more so than any mechanical advantage gained. That said, regarding the “upgrade” I was more referring to a heavy duty setup. So I’ll just plan a HD stock setup. I certainly don’t want to create more maintenance!

 

[OldButStillJeeping]

Control arm length is based on your front driveline angle. You want the axle somewhat centered in the wheel wells and the front diff pinion alignment with the driveshaft to be near zero in a rested on the ground position. If your lift is 'too high' you will not achieve that without knuckle rotation. If it's just a crawler that you trailer to the trails, it doesn't matter.

 

[jjvw]

....
If you want some general numbers, Clayton off-road has a bunch of measurements listed in the instructions listed on the control arms PDF listed for sale on the web site. Not sure how accurate they are, but it’s a source.
Best of luck with your project.
View attachment 608549View attachment 608550View attachment 608551

Disregard Clayton. The starting length for the adjustable control arms is the length they are right now as they are packed in bubble wrap. The final lengths will be the lengths they need to be to correctly position the axle.

 

[Astala3]

Disregard Clayton. The starting length for the adjustable control arms is the length they are right now as they are packed in bubble wrap. The final lengths will be the lengths they need to be to correctly position the axle.

Yeah, I get that. They are the length they are now and will end where they end. I asked for the original lengths to have a reference. Do I necessarily need to have it, no. Do I want to know it since my current factory control arms are folded like an accordion, yes.

When I originally installed them, I measured factory lengths and added a 1/4". If I am remembering correctly, that was the suggested starting length for a 4" lift. Doing all 8 in the same day left no extra time to tune them by drive shaft angle. Then the jeep puked motor oil threw the side of the block. Needless to say, they were never fine tuned. I will say though, they did eliminate the drive shaft vibes that existed from the 4" lift creating that severe angle in the rear shaft.

 

[jjvw]

Yeah, I get that. They are the length they are now and will end where they end. I asked for the original lengths to have a reference. Do I necessarily need to have it, no. Do I want to know it since my current factory control arms are folded like an accordion, yes.

...

There is no reason to know or care about what factory length is. It is irrelevant information.

 

[Astala3]

Right. My curiosity was the reason I cared to know the lengths.

Anyway, much progress had been made on the body repairs.

Tear down

Replace

I am well pleased with the progress.

As for the bumper, I plan to use the boxed portion that mounts to frame to build a custom bumper. I've got a surplus of 1.75" x 3/16 wall pipe I scored from a local Burger King play place tear down. That was a score. I was driving by and seen things going into a dumpster so I stopped and asked them to set the steel aside for me. They were more than pleased to not have to lift it into the dumpster as well as more room for other stuff.

The axle was pushed back, passenger knuckle severed from the tie rod. I have decided not to resurrect this one only to drive it for a few weeks. Instead, I'll save the money and put it towards the 8.8 and Cherokee Dana 30 with rear air locker and 4.56 gears. I plan to grab that parts YJ in 2 weekends.

In the mean time, I will finish harvesting the remainder of my adjustable control arms from the yellow jeep. Get those in place on Big Red and prepare to truss and mount the incoming axles. Had to transplant the radiator from little yellow so I will need to burp the system.

Lost the radiator fan shroud in the wreck. The 2.5 shroud is way longer so I just cut it down to the 3" length of the 4.0 shroud. The worked nicely. Discovered the yellow jeep had halogen headlights so I took them too!

Anybody know what rattle can paint best matches Jeep Flame Red? I might try to resurrect my red fender flare...

I totally keep forgetting, the Yj also has a SYE installed! I have one that I never installed on Yellow cause I wasn't ready to bite the receipt for a drive shaft. Now I can do that too.

Best of all, God. He is so good. This wreck, albeit terribly inconvenient, has really helped this jeep build move forward.

 

[Strizzo]

I have a set of stock arms in a pile next to the house if you want measurements, but you should pull up the instructions for your lift kit to see what length they say to start your install at. That will give you a starting point where you can make your measurements and adjust for your particular rig.

 

[jjvw]

I have a set of stock arms in a pile next to the house if you want measurements, but you should pull up the instructions for your lift kit to see what length they say to start your install at. That will give you a starting point where you can make your measurements and adjust for your particular rig.

Why does a specific starting point matter when you are going to change it to get to the final length?

Does the starting point change depending on the new ride height?

How does an adjustable control arm manufacturer know what the ride height is going to be?

 

[Strizzo]

Why does a specific starting point matter when you are going to change it to get to the final length?

Does the starting point change depending on the new ride height?

How does an adjustable control arm manufacturer know what the ride height is going to be?

I was referring to a lift kit that would have come with the adjustable arms. for example, my skyjacker 2.5" kit instructed to start the adjustable lower arms at 16 and 1/16". Although, just to check what skyjacker says to set their arms at for the 4" version, they also say to set the lowers at 16 1/16" so thats probably a decent starting point. Realistically, whatever he had his arms set at on the old jeep is probably a pretty good starting point too.

 

[jjvw]

I was referring to a lift kit that would have come with the adjustable arms. for example, my skyjacker 2.5" kit instructed to start the adjustable lower arms at 16 and 1/16". Although, just to check what skyjacker says to set their arms at for the 4" version, they also say to set the lowers at 16 1/16" so thats probably a decent starting point. Realistically, whatever he had his arms set at on the old jeep is probably a pretty good starting point too.

Why does a specific starting point matter when the length is going to change into the final length?

 

[Rickyd]

If the yj has a vacuum disconnect front axle you don't want to use it. Beware the older cherokee knuckles they are weak.

Hopefully its transfercase has the right input gear spine and length to bolt up to and seal your transmission.

It is possible your transfercase took quite a hit when the front axle was pushed back,compressing the driveshaft.

Trusses are a waste of money on a tj

Welcome,and props for bringing your tj back from the dead!

 

[Astala3]

The starting point for the adjustable control arms only helps to make less adjustments at the guess work of a lengthened control arm.

The truss are more for the ease of bracket placement and spring mounts.

I was a little worried about the transfer case. I’m hoping it’s ok. Won’t know till I’m under there.

 

[Astala3]

so i've just learned that the front axle on that Yj I'm picking up next weekend isn't from a Cherokee after all. its just the Yj Dana 30 axle with a Cherokee passenger side axle shaft to eliminate the 2pc shaft and vacuum 4x4 evidently.

That being the case, I think I am now going to harvest the Tj Dana 30 from the yellow jeep and pull the 4.56 ring and pinion from the yj. I've never down a regear before. After watching a few hours on the tube, i think I can pull it off. Anyone done this before or see any problems transplanting from Yj to Tj? did the Dana 30 change anything that would prevent this from working? If I'm not mistaken, the 4.56 should fit the stock carrier correct?

figure I'll grab a bearing press from Amazon for the bearing races. I can use a gauge from work to check backlash. I'll be able to inspect the gears. any recommendations for an affordable front locker? anyone have a takeoff they're willing to let go? why do it twice right, might as well get it in there while its open...

 

[Astala3]

Ok. plans changed again! imagine that, right...

not that anyone cares or is following this but I'll update all the same.

The YJ seller sent me more pics of the axles. This is when I learned that Yjs have HP D30s. As you likely already know, HP30 gears are reverse to the LP30. Obviously, I can't pull the ring and pinion as I had previously hoped. After this discovery, I was immediately concerned with the LP30 truss kit that was already ordered and paid for.

I ordered the truss kits from a semi-local fab shop, not the brand names most guys are running. Found the guy on the marketplace, parts look great in the pics, reviews are all awesome. I just got off the phone with the parts builder, Casey. Great guy, very knowledgeable. He said it would not be hard to make reliefs in the truss kit to accommodate the odd box on the passenger axle shaft housing. He is even going to include an extra slab of plate steel to lay over the top of the truss where it bridges the new relief cuts, no extra cost to me. Casey said, his parts also include his knowledge. Said he's pleased to help with anymore issues or questions. This is why I prefer local builders to big brand parts. Can't get that sort of service from a parts website!

In case you are wondering prices.
8.8 swap truss kit $280
Dana 30 truss kit with all brackets $300
shipping $50

since I'm back to not buying ring and pinion gears, I plan to at least run the Spartain Lunchbox up front. Again, I'm in the market for a front locker. You got one lying around? Let's talk!

 

[astjp2]

Ok. plans changed again! imagine that, right...

not that anyone cares or is following this but I'll update all the same.

The YJ seller sent me more pics of the axles. This is when I learned that Yjs have HP D30s. As you likely already know, HP30 gears are reverse to the LP30. Obviously, I can't pull the ring and pinion as I had previously hoped. After this discovery, I was immediately concerned with the LP30 truss kit that was already ordered and paid for.

I ordered the truss kits from a semi-local fab shop, not the brand names most guys are running. Found the guy on the marketplace, parts look great in the pics, reviews are all awesome. I just got off the phone with the parts builder, Casey. Great guy, very knowledgeable. He said it would not be hard to make reliefs in the truss kit to accommodate the odd box on the passenger axle shaft housing. He is even going to include an extra slab of plate steel to lay over the top of the truss where it bridges the new relief cuts, no extra cost to me. Casey said, his parts also include his knowledge. Said he's pleased to help with anymore issues or questions. This is why I prefer local builders to big brand parts. Can't get that sort of service from a parts website!

In case you are wondering prices.
8.8 swap truss kit $280
Dana 30 truss kit with all brackets $300
shipping $50

since I'm back to not buying ring and pinion gears, I plan to at least run the Spartain Lunchbox up front. Again, I'm in the market for a front locker. You got one lying around? Let's talk!

I do have a 30 locker, from 1997 sitting in a wreck. I am just too lazy to pull it! Hahaha

I also have 3 tj 30’s and one hp30, invest into getting your hp you want and done. No redo necessary and it really helps the pinion angle.

 

[Astala3]

I do have a 30 locker, from 1997 sitting in a wreck. I am just too lazy to pull it! Hahaha

I also have 3 tj 30’s and one hp30, invest into getting your hp you want and done. No redo necessary and it really helps the pinion angle.

I finished this build months ago. I did finish the high pinion Dana 30 truss kit and installed the no-slip Torq locker.

I haven’t been in this forum for a couple months. since I learned the hard way that the moderators aren’t for free speech. Tried to have a decent disagreement of issues and dude tags his mod buddy then says something stupid to me and then I’m blocked out of the thread.

Some good info here but the people with the power to silence everybody run it like a bunch of whiny liberals. Knowing that has ruined this place. I’m good. They can keep their censorship!