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

[tbangert]

Could possibly be the slip yoke on the drive shaft. They can dry out a little bit causing them to stick a bit and cause a clunk when stopping. You can pull the drive shaft out of the transfer case and clean the yoke then add some grease to it. Thats what it sounds like to me, I could be wrong...

[bdp1978]

I had the same symptoms last Summer in my truck. Mine turned out to be the stock panhard bar, it would bind and then "Clunk" really loudly when it unloaded in turns. I realize thats a completely different direction than what you were diagnosing towards, but Im just throwing it out there.

[Karo]

It´s not when stopping! It´s when having stopped and then driving after one or two meters turning into left or right (for example stopping before a corner and then driving forward turning to left or right). Doesn´t have occurred when driving a street forward and then turning into a corner without stopping. Sorry that i could not clearly describe that.

[Karo]

I had the same symptoms last Summer in my truck. Mine turned out to be the stock panhard bar, it would bind and then "Clunk" really loudly when it unloaded in turns. I realize thats a completely different direction than what you were diagnosing towards, but Im just throwing it out there.

That´s what i wanted - Ideas, thank you i´ll check the panhard bar too.

[Gordinho80]

I had a clunk from my panhard bar last year. It was noticeable over any bumps.

Now, I have a clunk over bumps, but it is not the panhard bar. I'm able to reproduce it if I shake the rear wheels back and forth. I'm thinking perhaps the C clips in the rear diff. My diff is due for a fluid change, so I will be examining it when I drain and clean.

[Trail X]

Karsten, I had a weird thing similar to this a few years ago. I had a bump occur only after I had been going forward, and then making a reverse turn (like when parking backwards).

I had a really hard time identifying the source, and it sounds like you are too.

I ended up locating it by having my wife perform the maneuver while I walked beside the truck to listen to where the sound was coming from.

Mine ended up being that the front peice of the IFS subframe had been bent in such a way that it was getting caught in some strange way on the IFS and making the bump sound when the IFS arm turned in the right direction. I hope you're as lucky as I was.

I tell that story to say that you need to get your ears on it. Get someone to drive it while you stand outside the truck and listen. First try to locate if it is front, middle or back of the truck (I know you said back, but it's nearly impossible to properly locate a sound from inside the truck). Then you can start narrowing it down from there.

My first thought was also the slip yolk, but the fact that it only happens during a turn after a stop is rather strange. Makes me thing it's a joint in the front suspension that's got some strange wear on it.

[Karo]

I´ll check the panhard bar too. The Problem with walking by the car and hearing it from outside is that the clunk is not very often it´s only sometimes.
The clunk and bump feels like coming from behind or under me like some pushing from the side. When i had replaced the transfer case output shaft seal i haven´t greased the slip yoke as there was some oil that i could see in the slip yoke. But i´ll redo that on weekend.
But from the feeling it is some heavy metal which is binding and then releasing. Many things to check and hopefully i´ll find something. That drives me crazy,

[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?

[fishsticks]

Left side gear looks ok.

Welcome to the broken G80 club.

[dvanbramer88]

[The Roadie]

Interesting. That wear pattern is certainly one of the "if you see this pattern you need to change the shims" kind of illustrations.

You've seen the pictures of my grenaded 8.0" G80? Drove on it for 20+ miles.

[navigator]

Is that a D35?

[Karo]

Installed the 8.6 rear axle last weekend and now the TB is running with the rebuild axle. Added the airlift 1000 bags and some spacers under the rear coils. Brake pads and rotors are new too. Finally did a test drive and now I am, really happy to drive the car after 5 weeks. The biggest problem was to get the bolts back in the rear axle pinion yoke. The thread inside the holes were rusted and i had no tap to screw a new thread in. WD-40 has not helped but I could get the bolts back in slowly with cleaning the threads with the help of a oil called Ballistol.

Some pictures of the swap: