How to safely drop 42RLE transmission on 2005 LJ enough to remove the wiring harness

[BradyM]

Hi all. My first post. I’ve searched this forum and YouTube and haven’t found any help so far. I have a 2005 LJ with 4.0 and 42rle tranny. Bought the Jeep in mostly stock form about 6mo ago and have plans to build it myself (had a YJ years ago and wanted to build it, but life had different plans - I’m more able to build one now and I’m finding it very relaxing and enjoyable). I want it to be reliable enough to trust it on 4hr road trips for light wheeling. When i bought it I was having a few electrical issues (nothing happening when I turned the key, but would eventually start), then it died on me when I hit a bump and will now turn over, but won’t start. So i started out to check fuel and spark. No fuel pressure in the rail when I turn the key on, fuel pump relay checked out and 12volts to the fuel pump relay coil, so I assumed the fuel pump had gone out. Installed a new one, but still no fuel pressure in the rail. Upon further investigation, i found no continuity on positive wire to the fuel pump. Unplugged the harness at the back of the engine bay (C104) and had continuity from PDC to C104, but nothing from C104 to fuel pump connector at the fuel tank. The wiring loom is very brittle and has fallen off in many spots. I saw an area where the wiring harness goes under the firewall that appeared to be chaffed. Long story short, I’m removing the entire wiring harness to check/rebuild/assure myself given the other electrical gremlin).

I’m pretty sure I have disconnected all the wiring harness connectors, I’ve removed the skid plates and drive shafts, but I can’t lower the transmission enough to reach above to completely free the wiring harness (possibly hung up on transmission dipstick tube). So what I want to do is make some more room for access: either disconnect all t-case and tranny linages and lower the tranny more, or if needed disconnect the motor mounts, or raise the tub. I eventually plan to do a body & motor mount lift and tummy tuck at some point in the future, so right now might be the perfect time to do that given where I am…

So main question after the rambling would it be easier to lift the tub and do the body lift now than to lower the tranny in some manner?

If lowering tranny is the easier route and I disconnect the linkages, will the motor mounts provide enough movement to lower the tranny much more? If the motor mounts have enough slack, do i risk damaging anything (exhaust,…)? And if the motor mounts don’t have enough slack and I have to disconnect the motor mounts, how do i support the engine while they are disconnected?

I work 28 days on and 28 days off. I’m on my way to work now and just keep trying to think of ways to get this done. Figured I’d ask here so maybe progress doesn’t stop while I’m away and maybe order body lift and motor mounts lift if thats the best route. Thanks for any suggestions.

 

[sab]

So main question after the rambling would it be easier to lift the tub and do the body lift now than to lower the tranny in some manner?

Without knowing exactly what state of disassembly you have your TJ in right now, it's hard to answer this one.

will the motor mounts provide enough movement to lower the tranny much more?

The motor mounts provide quite a bit of pitch. More than you'd need.

If the motor mounts have enough slack, do i risk damaging anything (exhaust,…)?

I would recommend removing the exhaust if you're going to lower the transmission. The expansion joints at the top of the cats aren't that flexible.

I'm sorry I'm not much more help than that. My 2005 LJ (manual transmission) has been disassembled from the engine back and from the frame down for so long that I can't recall all the steps required to lower the transmission.

 

[sab]

Also, there are two metal brackets on the screws that mount the transmission to the engine that the harness is clipped to with christmas tree fasteners, and that might be what's keeping you from removing the harness.

 

[BradyM]

I think I remember removing at least one Christmas tree from the top, i might have missed one though. I just watched a YouTube video for body lift and engine mount lift while in the plane. I think I’ll probably install the body lift and motor mount lift when I get home and just lift the entire tub enough to remove the harness (and reinstall it). Thanks for the response. Hope you get yours back together soon.

 

[hear]

I've never run into this problem since I normally work on the 3 speed but you might find it easier to remove the center console & shifter plate thing to give you access to the top of the transmission, so you can clear whatever is hanging you up there? Usually once you remove the skid you can raise lower your jack to give you access over the top of the transmission.

Inspecting your harness will be a rewarding task, guaranteed.

I would recommend removing the exhaust if you're going to lower the transmission. The expansion joints at the top of the cats aren't that flexible.

If the exhaust is a real concern just remove the transmission mount & exhaust hanger. I've never had to remove an exhaust to drop a transmission. Unless the 4spd is wildly different in this regard?

 

[BradyM]

Thanks hear. Transmission would only lower so far. I was assuming the linkages were catching it or the motor mounts only had so much flex. At least now I have a few options for when I get back home. And yes, I’ll feel better after I’m able to fully inspect the harness.

 

[hear]

Thanks hear. Transmission would only lower so far. I was assuming the linkages were catching it or the motor mounts only had so much flex. At least now I have a few options for when I get back home. And yes, I’ll feel better after I’m able to fully inspect the harness.

The t-case linkage is a mechanical one, and it does need to be disconnected if you want to lower the trans. I have a cable shifter (as many here do), so I forgot to consider it. The throttle & shifter are also cables from the factory, so they shouldn't need to be removed.