4.8is transmission grind/crackle sound

[blabla30]

Hello everybody,

I have the same sounds as the guy in this video:

https://www.youtube.com/watch?v=ZDcry6rw6Nc

Unfortunately there is no information about the cause of this sounds.

Has anybody the same issue? What could it be?

[wpoll]

Sounds a little like the CV joint at the front of the rear diff. If the joint gets dry, the balls in the CV drop inside as the load on the CV joint is reveresed (from R to D and back again).

[Nolimite39]

The dry balls drop. . . . hahahaa. . . I'm a child.

[Rockit]

Mine was broken rusted bolts on the transferase shaft. Easy fix if you have a lift.

All the bolts were broken except one and when you go from rev to drive the shaft spins and rests on part of the transfer case.

[blabla30]

Originally Posted by Rockit

Mine was broken rusted bolts on the transferase shaft. Easy fix if you have a lift.

All the bolts were broken except one and when you go from rev to drive the shaft spins and rests on part of the transfer case.

Could you please show me which bolts you mean?

Part groups | BMW X5 E53 X5 4.8is N62 Europe

Thank you in advance.

[blabla30]

Originally Posted by wpoll

Sounds a little like the CV joint at the front of the rear diff. If the joint gets dry, the balls in the CV drop inside as the load on the CV joint is reveresed (from R to D and back again).

There is no boot as far as I know. Is there a possibility to check it and add grease at first?

[Rockit]

Originally Posted by blabla30

Could you please show me which bolts you mean?

Part groups | BMW X5 E53 X5 4.8is N62 Europe

Thank you in advance.

I had it done by a shop.

The best thing to do is get under the car safely, preferably jack up up on stands or a lift. Have someone do that, put into reverse than drive and listen and see what it is.

I know a lot of the things happen the same on these cars but you can't diagnose on a post. See if the noise-clanking is external or internal. If the shaft bolts are broken you should clearly see and hear it but look up on the small transfer case shaft.

[Rockit]

I believe the end of the shaft has like 4-6 bolts? its solid no rubber boots or bearings.

[blabla30]

Originally Posted by Rockit

I had it done by a shop.

The best thing to do is get under the car safely, preferably jack up up on stands or a lift. Have someone do that, put into reverse than drive and listen and see what it is.

I know a lot of the things happen the same on these cars but you can't diagnose on a post. See if the noise-clanking is external or internal. If the shaft bolts are broken you should clearly see and hear it but look up on the small transfer case shaft.

Already did that and neither me or the mechanics at the shop could figure out where it's coming from.

They think its the drive shaft itself and would replace it... I´m a little bit afraid to change it and the noise will still remain. Also I´m not thinking I´m the first one with this sound and now I´m searching for somebody else who already solved this issue and could give me a hint.

[andrewwynn]

X-drive so you can disable the front? Isolation is the best way to track it down.

It sounds to me like flexing. Engine twisting on the mounts and something like a heat shield is rubbing.

You can use a microphone on an ear bud and an FFT app (they aren't free I paid $10-15 for mine just do it).

Does this only happen when shifting into and out of gear or also of you are not moving in gear and hit the gas?

My car has some drive train flex that causes an actual thump when I go from rev to fwd I think it's subframe or rear diff mounts