Rear end swap

[Jrcm10]

Hello everyone. New member here. I just recently bought a 2006 liberty 4wd 3.7 at a auction lien sale. As I was driving it home the jeeps rear end started pulling side to side and all of a sudden the driveshaft broke off the differential and the differential housing is broken more like grenaded. I was able to limp home on the front driveshaft thankfully with a alot of clanking from the rear differential. I didn't buy it for to much less than 1k and it's pretty clean with 135k miles. My question is has anyone Swapped the rear differential or rear end completely? Just wanted to see what I'm getting myself into. Rear ends are pretty cheap so I want to fix it and learn something from it lol. Any help will be appreciated

 

[04Liberty]

First, get your factory manuals: https://www.jeepkj.com/threads/factory-service-and-parts-manuals.58752/
Dropping a rear axle is pretty straightforward, especially a coil sprung one. Sounds like you're gonna need an axle and a rear driveshaft (I wouldn't trust the original after that). Better make sure your t-case didn't get messed up too. Just make absolutely sure you get one with the same ratio as your front (this is non-negotiable) and is compatible with your onboard electronics (sensor locations can vary).

 

[duderz7]

'06 is when the abs system changed, so nothing '05 or older, same engine size should have same gear ratio.

 

[Jrcm10]

Thanks for the link. That'll be super helpful! Gear ratio should be 3.73 right? It's an automatic. I inspected the t-case and surprisingly looks solid. Also upon further inspection of the rear end both brake lines were cut. Probably explains why brakes didn't work well. Got my work cut out for me lol.

 

[tommudd]

Yes if 3.7 and automatic its a 3.73
Easy to swap rear diffs , have done a bunch of them
I hang the calipers , remove brake lines from diff but do not detach them either
shocks , let them hang
speedo pickup on 02-05s
rear tri link, I unbolt bracket and all
lower control arms and of course driveshaft1/2 hour or so for me any more
But for yours ( after 05 too many electronic geegoozs ) so watch all wires

 

[Jrcm10]

Hey guys so I thought you guys would like to see what happens when the differential grenaded. Taking the whole rear end was pretty easy after I disconnected all the wires. Brake lines were cut so I didn't have to worry about that. I do need to replace a parking brake cable on the driver's side because it was cut before the hook thing that clips on to the spindle I think. Ordered a used rear end from automotix for 300 bucks shipped so ill update more after I start putting it back on.

 

[lfhoward]

Oh wow that’s crazy! Never seen a diff do that before.

 

[Jrcm10]

Oh wow that’s crazy! Never seen a diff do that before.

Yeah not sure what happened. I was thinking it had no fluid

 

[DeVilliers]

That looks more like it overheated and melted down. Wow!

 

[JeepJeepster]

Thats an odd situation there. Since there is a C-clip laying there and you say the rear end went side to side, I'm thinking something happened to an axle shaft. There is also a bearing roller laying there. I'd say something got sucked between the pinion and ring gear.

 

[Jrcm10]

So update. I got the rear end and driveshaft and it took sometime putting it back on since I was solely working on this alone. I used two Jacks to lift up the rear end and lined it up with the rear control arms and bolted it on along with the shocks. Bolting on the driveshaft was pretty easy. Lining up the upper control arm was a pain since I didn't have a 2nd pair of hands lining it up as the rear end kept dipping forward. I replaced the brake lines from a donor jeep and bought new parking cables and pushed them through the holes under the jeep (those grommets are a pain). Flushed new brake fluid through all 4 wheels and changed the gear oil on the new diff. ***** it doesn't have a drain plug. After double checking my work I took it for a test drive and everything was working good until I realized I had a coolant leak at nose of the water pump. My KJ has an electric and viscous fan. I think whoever owned this jeep before me did the big cooling upgrade and added the viscous fan not sure. The bolt to take off the viscous fan is a real pain in the butt since mine was seized and rusted. I was defeated trying to take that bolt off so I took off the water pump with the fan still on it and tried multiple ways to loosen that bolt with no avail. Soooo I destroyed the water pump with a sledge hammer and was able to free up the clutch but destroyed it sadly. I was still able to salvage the fan but will eventually replace the clutch with a new one from Amazon. I was reading up on the cooling system for the KJ and apparently these came with just an electric fan but u can add extra cooling by adding on the clutch since the water pumps had the threads for the viscous fan.
So all in all this was a great experience for me since I've never replaced a rear end before. I've learned alot and if anyone decides to tackle there rear-end I'll try my best to help out. I apologize for no pictures but I worked on this project alone. But yeah it was an experience nonetheless

 

[sleazy rider]

Glad to hear it's all back together and functional. Learning experiences are worth every penny and build confidence in taking care of other big tasks with these little buggers. Water pump's easy compared to what you just did.


SKIP THE AMAZON parts. Get either OEM or a well recognized manufacturer's replacement part.