Hey y'all, I just did a 4X4 swap on my '98 xj 4.0, and all seemed to work fine, the only thing that has me kind of worried as that normal driving speeds under 40mph no problems hitting bumps and drives just fine. but anything over 50 mph and i hit a bump on the highway, the rear end sounds like its almost skipping, I replaced the old shocks so i know its not that. it almost sounds like its jumping a tooth in cog and it can happen multiple times in a row. can explain further on what I did replace if necessary.

 

Is it a shuddering like a vibration? Or do you mean the rear tires are skipping like hopping? Chirp chirp chirp?

How are the engine mounts, trans mount, universal joints?

 

i cant tell if its wheels hopping but its more of metal clunk and it jerks, i swapped the engine mounts and tranny mount when i did the swap so those should be fine, the only thing i touch was the new rear drive shaft, rear shocks and swapped the diff fluid on the rear end. i'm thinking it might be a lose shock bolt cause the anchor on one of the driver side rear was kinda stuck but i impacted it back on and its not going anywhere.

 

Update: after some light diggin into bad U joints, it almost sounds like exactly what my problem is. is it easier to just swap the drive shaft entirely or just swap the u joints on said drive shaft?

 

Replacing the shaft would be easier for sure but it's an expensive way to save some time & effort. Your Jeep, your priorities..

 

DANA SPICER 5-1310X - 1984 to 2001 Jeep XJ Cherokee Compact FRONT Driveshaft Universal Joint 1310 Series NON GREASABLE

Dana Spicer 5-153X 1984 to 2001 Jeep XJ Cherokee Compact Rear Driveshaft Universal Joint 1310 Series GREASABLE Fitting in Body

I bought two of each hopefully this is the last thing i need to complete the build.

 

I hope it goes smoothly and fixes your problem.

It wont be.

 

I wouldnt trust many shops to install ujoints correctly let alone a inexperienced guy new to wrenching.

Watch lots of vids . learn practice and repeat.

 

Update: just had the rear drive shaft rebuilt and it does the same thing hard jerking as soon as it shifts into 5th, i did a test drive with out the rear installed and no problem, so now I know its not drive shaft related, could it be a bad T-case? i swapped fluids on it so that should be goods i just cant tell whats making it jerk like that in 5th.