Heavy clunk from the rear or transfer case

[KaRo]

I have a heavy (really heavy) clunk coming from the rear or behind me in left or right turns after stopping and accelerating. After that car drives normally, error occurs sometimes. When feeling the bump and hearing the clunk my thoughts are "that could be expensive"... Driving is in 2Hi have not checked so far if this is also in 4Hi. Car feels like getting bumped from the side and a heavy clunk is hearing. I have looked to all components on the rear all is tight and bolted. Transfer Case Fluid is correct and the flush was made in mid december. Haven´t driven the car since the flush very often. So hopefully i can get some ideas. Plans for the weekend are checking fluid level on the transfer case and checking the rear differential and the locker. Anything more?
Need help..
Karsten

 

[AtlWrk]

I immediately think of this thread:
http://gmtnation.com/f79/feels-like-i-get-rear-ended-when-sitting-red-light-2430/

Basically it's a problem with the slip yoke that connects the driveshaft to the output shaft in the transfer case. The splines in the yoke bind on the output shaft--particularly when braking hard. When it breaks itself free you get a thump and feeling of getting bumped.

You can pull the driveshaft and grease the splines as a temporary solution. For some people that is enough, for others there are improved replacement parts intended to permanently eliminate the problem (see linked thread).

 

[CaptainXL]

My guess is that the rear differential fluid level has never been checked and it all leaked out through the rear wheel seals. Major expense.

 

[KaRo]

My guess is that the rear differential fluid level has never been checked and it all leaked out through the rear wheel seals. Major expense.

Hm that must be very much.. personally i haven´t checked this but my the company who did the maintenance had. But ill look into that on weekend.

 

[KaRo]

So today i had the time to find the reason for the clunk bump tralala thing.
I have checked the rear differential and Ladys and Gentlemen here are the pictures:

broken spider gears:

Millions of fragments:

After collecting all parts out of the differential housing, i decided to reinstall the cover and fill the differential up with the old filtrated oil.

And guess what, I drove home like nothing ever has happened. I love my TB

Next things to do is changing the wheel bearings and axle shaft seals on this new painted 8.6 axle:

Could someone please tell me if this wear pattern on the left side of the spider gear is normal or did I have to replace it?

 

[CaptainXL]

Damn. Sorry to jinx ya.

The important thing to do before replacing the bearings and seals is to thoroughly degrease and remove any metal shavings or powder after removing everything. This ensures the seals will not get chewed up. Just thought I would add that in case you never thought of that. In other words make sure everything is clean prior to assembly. Even if that means running a swab and magnet down the length of the axle for instance.

 

[KaRo]

Damn. Sorry to jinx ya.

The important thing to do before replacing the bearings and seals is to thoroughly degrease and remove any metal shavings or powder after removing everything. This ensures the seals will not get chewed up. Just thought I would add that in case you never thought of that. In other words make sure everything is clean prior to assembly. Even if that means running a swab and magnet down the length of the axle for instance.

No Problem, the spare is in my garage.
Good point with the magnet! At the moment I´m waiting for the axle seal and bearing remover..