: Transfer case, front drive shaft tech question



dssrocks
07-30-09, 08:43 AM
I have recently had the tranny replaced on my truck (2006 Ext). Since then I can hear/feel a clunking sound coming from the drivers side under the floor when I go over bumps under acceleration or while I have a load like a trailer. The truck has been back to the dealer a few times to try and find it and the clunking noise still remains.

I was just under the truck and have found if I shake the front drive shaft there is a knocking sound heard from where the drive shaft goes into the transfer case. it would appear ro be coming from after the U-jooint from where that rubber boot is just entering the transfer case. Should there be any play in this area that could make a noise? Could having the transmission replaced caused this to happen? As this noise what not there before the tranny was changed. I am hoping I have found the source. Any help or suggestions would be greatly appreciated.

Thanks in advance.

dssrocks
08-01-09, 11:22 PM
anyone?

sk7
08-02-09, 12:43 AM
I'll have a look later today on my truck to see if the front driving shaft has the same issues as yours. Since the noise is suspension related, I would suspect it comes from the back end. Front drivetrain is isolated from the movement of the wheels by the independent front suspension. I would suspect loose or damaged tranny mounts when the repair was done. What is their excuse for not finding the problem?

dssrocks
08-02-09, 12:32 PM
I'll have a look later today on my truck to see if the front driving shaft has the same issues as yours. Since the noise is suspension related, I would suspect it comes from the back end. Front drivetrain is isolated from the movement of the wheels by the independent front suspension. I would suspect loose or damaged tranny mounts when the repair was done. What is their excuse for not finding the problem?

Bit of a long story, had the truck fixed out of town when I was on vacation while pulling a trailer. I do a have a warranty on parts and labour from GM but the dealer has not been able to locate the problem yet, and it is a pain to keep bringing it back. Would like to solve the issue for them as it is even hard to mimic the noise on a short test drive, so you can see what an issue it is when I bring it back to the dealer.

Would be great if you could see if your truck does this. I would like a detail of the transfer case so i could understand what could be the problem.

sk7
08-02-09, 10:16 PM
Had a look under my truck this afternoon. Good thing I did I noticed one of the O2 sensor's wire was rubbing against the front driving shaft! No harm done yet. That sensor has been replaced by the previous owner for sure and the connector wasn't put back in its proper place.

I get no play or noize coming from the front drive shaft moving it front to back. Its tight in there no noticeable play at all. When turning it there is a bit of a clunk coming from the transfer case, but not much. Looking under I can see removing the tranny must be a hell of a job! There's a lot of hardware to remove around that area.

dssrocks
08-03-09, 02:35 AM
thank you for checking into this. i will post my results when it goes back this Wednesday to the dealer.