I changed the oil in my 98 Classic today and while it was on the lift I spun the right front tire and heard a clunk clunk clunk come from the center of the differential.I went to the left front tire and same thing clunk clunk clunk.I can turn the drive shaft and the tires move and no noise.Is this normal?Ive been feeling a little binding going on when turned very hard.I turned the tires all the way and spun them while on the lift and no binding.The axle u joints seem fine.I know for a fact the noise is coming from behind the cover.Im gonna try to lift it up again tomorrow and take the front cover off and inspect it.Anything in paticular I need to be looking for?Also the fluid had a red tint to it but its gear dope for shure.Any ideas?I used the 4x4 alot this weekend at the beach with no issues or noises.

 

Any metal, spider gears?

 

No metal that I have seen.It almost seems like the front is still in 4x4.I know the transfer case has released because I can turn the drive shaft by hand.Is there anything in the front diff that has to unlock when taking it out of 4x4?

 

Not unless someone swapped in an old vacuum disconnect or it has a locker.

 

Thanks for the replies Turbo not vacuum I checked for that first.I wouldnt imagine someone putting a locker in...the rest of the XJ is stock.I think Im gonna take the cover off in the morning and take a look at whats going on in there as I turn the wheel.

 

It still sounds like axle u-joints. Mine "looked" fine but were so dry and stiff I couldn't move them by hand. The only other thing I can think of is to check the center pin (mate shaft) for wear and/or movement its hole. It's not real common, but it does happen.

With the cover off and both front wheel off the ground you should see/feel where it's coming from. Get back with what you find.

 

Finally got some time today to take the cover off.Guess what...... no spider gears.Looks like a locker to me.When you spin one wheel you can see it spring back and jump teeth.Is this stock for a 98 or has someone installed an aftermarket locker?The rest of the XJ is bone stock. Thanks

 

Post a pic.

 

No automatic lockers came stock on XJs - closest was a Limited Slip Differential named TrakLock. Sounds like you found a surprise!

+1 pic

 

Heres a pic

 

Yup that's a locker! If you have the patience and/or care, remove the axle shafts and cross pin and get the unit out of there, someone on here should be able to ID it for you.

 

I totes have that on my xj. And I can hear a kinda clunking sound when I'm rolling around 10mph. And it was jumping teeth when I spun the wheel. Is it bad?

 

That's normal operation. When torque is applied by the drive shaft the springs keep the two halves pressed together with force enough that the teeth stay locked. When there's little torque, like going around a corner or up on a hoist, it should make a clicking, clacking, or sometimes clunking noise as the teeth ratchet about. Noise depends on lubricant, wear, spring condition, and design.

 

is it normal for the clinking to happen at slow speeds? I have a 92 4.0 4x4 lifted, I was experiencing a clunk thumping noise, I replaced u joints in front axle, hub and bearings. Reduced thumping a lot but still sounds like a nice thumping and I can feel it through the driver side floor.