I have a 90 XJ with a 97 front axle in it (no CAD). No noise in 2WD. In 4WD coasting, no noise. In 4WD with throttle input there is a 'not happy' sound coming from the front of the vehicle. I can't pinpoint the exact area. I rebuilt the jeep about four years ago - complete rebuild of both axles, all new suspension, went through TC, motor has ~50k miles on a rebuild. Minimal use in the last year, maybe 1000 miles on it with no off road use. A few years ago I did a good amount of driving on the beach and the jeep is getting a bit rusty.

To diagnose the issue I have done the following: checked TC fluid - was full and dirty, changed the fluid. Drained the front axle, inspected internals - looked good, replaced fluid.

I plan to go wheeling this upcoming weekend and would really like to figure this out. Thanks all.

 

I'm just guessing here, but I'd suspect the front driveshaft first. It's also possible that it's your front carrier bearings or pinion bearing, but check those U-joints first. Also check your front axle joints as well.

 

Next question - is it going to blow up in the next 1000 miles of street driving and ~50 miles of light off road use? I have plans this weekend to go out with my father to Uwharrie. Not looking to get too crazy, just some trail riding.

 

I had the same problem a few years ago. It turned out to be the centering bushing ball thing in the front driveshaft. I cant for the life of me remember what it's called exactly lol

This part

Left is probably original. It was shot

 

It's all guesses. I could tell you it'll make it to the grocery store and it could come apart on the way there.

Luckily, there are still plenty of 4wd XJs in U-pull-it junkyards. A front shaft is usually around $35.

 

I have two front shafts on a shelf in the garage. I'll throw them in the back of the jeep for the trip. Worse case, I'm slapping one in on the side of the trail. Thanks guys.

 

make sure you have the right tools for the swap!

when I had to drop my front driveshaft I had to dig through all my tools to find the correct wrench. Luckily I was at home because I absolutely did not have that wrench with the tools I keep in my XJ. I cant remember what exactly I needed but it's in the top of the Jeeps toolbox now

 

I just put the front shaft back in it Saturday. I used a 5/16" ratcheting box end wrench for the axle flange and a 1/4" ratchet with 5/16" shallow well socket for the TC flange. I'm a 'pack the kitchen sink' type, I'll bring a bunch of tools with me. Good call on packing the tools that make a DS swap easy, especially considering it may be a real possibility. Half the fun of wheeling a 30 year old rig, right?

 

My jeep trip got postponed, we just went out this past weekend. It was a 250 mile drive to Uwharrie from the house, drove about 20 miles in the trails, and then 250 miles home (stayed the night and drove back in the morning). The jeep did pretty good. Bit of noise from the front end when I got it over 70, nothing too crazy. With the radio on, it was barely noticeable. In 4LO on the trails, running between 5-15 miles an hour it was quiet. I think the joints all just needed to recirculate the grease and knock the cobwebs out. Was a good trip with no surprises. Thought I would report back for any people searching in the future.

 

Glad to gear it worked out.. Which trails did you take at Uwharrie? There are some serious ones out there for sure.

 

I'm sorry to report, I don't recall. Just kind of wandered. I stayed clear of Daniels, outside of that I just wandered trail to trail. Since I drove the Jeep out there, I skipped any really rough looking obstacles.