ArmySgt97

Hey guys. I was wondering if you could help me with this one. Bare with me I will try to explain this as best as I can. When I engage 4 wheel drive I get a constant clunking sound from what sounds like the front drive shaft or possibly the T-Case (I hope this isnt the problem). It only does it in 4 wheel drive and no other time. 4 wheel still works just fine aside from the noise. If it is the T-case, how hard is it to rebuild it with a rebuild kit and possibly a chain? If not the T-Case, could it possibly be the drive shaft? I have had it up on jacks and rotated the front wheels to try to find the noise but nothing. I dont hear anything in the diff. Also while I had it on jacks I turned it on and put it in drive while in 4 Hi and 4 low and listend and I didnt hear anything either. Seems to only do it when I am actually driving it. Any Ideas? I dont hear anything in the diff but I am going to pop it open in the next couple of days to replace the fluid and check out the gears. Thanks for any help.

BTW the clunking seems to coralate with the spinning of the drive shaft, ie, the faster I go, the faster the clunking is. Thanks again.

jd4x426

this just happened to my buddies he had the 242 with his the chain was skipping teeth making a horrible popping noise that could be your problem does it only happen when you get on the throttle

ArmySgt97

No, it is more of a constant sound when in 4 wheel drive. It doesnt really pop, it sounds almost like a tank. That is the best description I can give it. It is consistant with the rotation of the drive shaft. I dont get any skipping or anything like that and 4 wheel drive works great. Just that sound like a tank.
BTW, thanks for the reply!

ntneustadt

that would be my first guess would be the transfer case. I got my whole trans rebuilt and the guy said that he chain was really loose. you could try getting it checked out of change the front differential and transfer case fluid.

BlueXJ

Sarge check the axle universal joints and if your particular XJ has a vacuum disconnect that should be checked as well. HTH
Blue

ArmySgt97

Thank you for all the replies and help. Right now I am changing out the rear diff Gears and Carrier so it will have new fluid in the front and back when I am done. I will check the Axle u joints when I have a chance.
I just bought a Transfer Case Rebuild kit and chain a few days ago so whenever I get that I will knock that out and see what happens. Im starting to think that it may be the driveshaft but I am still not too sure.
I am going to have a friend of mine ride with me tomorrow to see if maybe he can help me pin point the problem. Thanks again for your help.

smicod60

ArmySgt97

I figured out that it is the CV Joint on the Transfer Case side of the Front Driveshaft. I replaced the U-Joints recently and they are tight but I am getting alot of play between the 2 U-Joints on that end.I believe you can rebuild that but I went ahead and ordered a new, heavier duty, full spline front driveshaft. But I am still going to rebuild my Transfer Case and replace the chain for GP. Hope that helps you!

jimperry6315

are you saying one c-v joint was making the clunking sound. I have same problem. I thought my chain was slipping off the cogs, but now i am not so sure. why would that joint only make the sound every few seconds and not all the time.

tkdtim

I also have a "tank" sound in 4x4. I have a spare transfer case I'm going to throw in. Maybe Blue or someone wiser than me can answer this. If it was the drive shaft, or front axle, why would it only do it in 4x4? That stuff all turns in 2wd also without the torque applied...

JodyW

I am new here, but by the way it sounds, I'd say definitly check your CV joints. I had an '84 Chevy 4X4 that the CV joints went bad on, and it was ratteling like a tank in 4wd. I believe the reason for this is due to the tension on the CV joints. When 4wd is disengaged, there is no "constant" pressure, they just kind of hang out holding your spindles on. When in 4wd, there is a constant pressure, twisting on the joints and the shaft, causing the noise - similat to when a chain is slipping on a motorcycle sprocket, it doesn't usually slip unless you are trying to go, but it will coast just fine.

trainer7

did you remove your front drive shaft and engage in 4low???? my 94xj is having same problem i did in fact find the front u joint a little bad so replaced then engaged 4low and still made the clunking!!! i then removed the front drive shaft and its still making the clunking noise i narrowed it down to the t case going to rebuild soon with new chain!!

ClassicXJ

Could be the U-joints. is it worse when you turn the wheel?

89 black

If the noise is not poping and it is more of a loud constant "tank" sound it is for sure your "drive line or axle" u-joints. I had the same problem and it was the drive line u-joints. And it would only make this sound if you were under constant torque like regular driving would cause. Lifting up on jacks would not give you the same sound because of the lack of constant torque. Hope this helps.
I curently have a hard poping going on and I am unsure what it is. It sounds like it is coming from the t-case, like the chain is skipping teeth or something. Let us know what comes of it. Thank you.

jimperry6315

definitely , u -joints , i have same problem and i just got it diagnosed. there is a build up of tension becouse they are binding, and then its released and you here that awful clunking sound