2wd to 4wd conversion

[That_Creepy_Guy_In_The_MJ]

Alrighty, so basically I have plans to convert my 1988 mj to 4wd and I just wanted to know like a small grocery list of items I'd need to get the job done.

Only reason I'm going 4wd is for the capabilities, and I'd like to put on a 4.5" lift kit.

[Francesco]

Okay, So I did this one myself. This is a COMPLETE(if i remember correctly) list of what I needed:
4wd Transmission

4wd pilot bearing

4wd shift linkage

front driveshaft and rear (different size)

4wd engine harness (if you want the 4wd light, etc)

front axle

front brakes (they weren't the same for me, i think it was the knuckles that were different which made the calipers different too)

i replaced my unit bearings too, AFAIK the 2wd ones have a plug you can remove, but IDK. I highly recommend finding an external slave transmission (assuming youre a 5 speed) while everything is apart. Will save you lots of time if your slave goes out (and mine already has)

[That_Creepy_Guy_In_The_MJ]

Thank you!

[Pete M]

manual or auto?

 

 

 

the pilot bearing isn't 4wd specific, that will change (or not) depending on what trans you put in.  :thumbsup:

 

not sure what you mean by the "4wd engine harness" but I'm pretty sure you're referring to the vacuum harness that runs off the t-case. 

 

and as he said, the brakes must match the new axle.  2wds are different and there have been changes on the 4wd ones over the years. 

 

now is the time for gearing upgrades.  better gears were available in 2.5L rigs and (unless you have the dana 44 rear) you'll want to upgrade your dana 35 too. 

 

now is also the time to consider the front U-joints too, as the later years of XJ (also the early 90s with ABS) has bigger ones.  these axle shafts are swappable into early axles if you find an early one with better gears. 

 

 

a donor rig can help with a straight swap, but no XJ came with all the goodies.  for example, even later 4.0 XJs had 3.55 gears at best. 

[That_Creepy_Guy_In_The_MJ]

Yea I have a manual 4 speed.

[That_Creepy_Guy_In_The_MJ]

And reason for the 4wd as mentioned is so I can lift it higher, and the capabilities

[davidh190]

manual or auto?

 

 

 

the pilot bearing isn't 4wd specific, that will change (or not) depending on what trans you put in. :thumbsup:

 

not sure what you mean by the "4wd engine harness" but I'm pretty sure you're referring to the vacuum harness that runs off the t-case.

 

and as he said, the brakes must match the new axle. 2wds are different and there have been changes on the 4wd ones over the years.

 

now is the time for gearing upgrades. better gears were available in 2.5L rigs and (unless you have the dana 44 rear) you'll want to upgrade your dana 35 too.

 

now is also the time to consider the front U-joints too, as the later years of XJ (also the early 90s with ABS) has bigger ones. these axle shafts are swappable into early axles if you find an early one with better gears.

 

 

a donor rig can help with a straight swap, but no XJ came with all the goodies. for example, even later 4.0 XJs had 3.55 gears at best.

 

Pete, my MJ is auto. How would I approach the 4wd conversion?

 

 

Sent from my iPhone using Tapatalk

[Pete M]

same principles.  just skip the parts related to the manual trans.  I believe there is a writeup in the DIY forum that cover using later model transmissions (the electronics changed over the years). 

 

http://comancheclub.com/topic/48710-diy-projects-writeups-master-search-index/

[mikekaz1]

Do yourself a favor and skip the factory linkage and get a bostwerks or similar stand alone linkage.

[That_Creepy_Guy_In_The_MJ]

Alrighty I'll do that