Drive Line Clunk

[duraman03]

I have a 2006 Quad cab short bed 4wd 2500 Cummins with a G56 6 speed. My question is since the truck was new it has a clunk when you let the clutch out. It is like there is slop at the tailshaft. The U-joints seem fine but you can move the drive shaft side to side and up and down where it slides into the back of the T-case/Transmission. I have just recently put a Southbend con-ofe clutch in it and this has amplified the clunk. The truck has 20k miles on it and I hate going to the dealer. Does anyone have any ideas or is this just normal?

 

[JApol]

The clunk is the slack being taken up in the joints. I have an auto and i am not sure how the drive shaft is connected to the transmission but I would guess a slip joint.



Remove the drive shaft from the truck. manually move around the u-joints looking for any play. If the clunk is as noticable as you say there should be some play somewhere in the joints. If the joints are good I would look at the inside of the slip joint on the front of the driveshaft and the rear of the transmission and look for wear. But my bets are that you have some wore out u-joints. The ones on my rear drive shaft lasted about 35k before they went out.

 

[Grizzly]

There was a thread on this problem about 5 or 6 months ago. Do a search. JApol is correct. It is in the U joints and is only common on 05 and 06 with the G56, 6 speed transmission.

 

[Grizzly]

There was a thread on this problem about 5 or 6 months ago. Do a search. JApol is correct. It is in the U joints and is only common on 05 and 06 with the G56, 6 speed transmission.

That thread is titled, "Is it normal to get a clanking noise from the driveline when releasing the clutch".

 

[SSalzer]

Mine does it also, but I have the NV5600. I had a 97 gasser that did the same thing with the NV4500. I was told it was the drive shaft torquing and untorquing itself. If I feather the clutch a little it doesn't happen. I think your south bend doesn't engage as smoothly as a stocker, so that's why you're hearing it more.

 

[RJWEST]

My 2002 ( nv5600 ) had a clunk, 'U' joints seemed tight,
I had the the carrier bearing and the 'U's changed,
Fixed the 'Clunk', Drive shaft guy thought it was the carrier bearing. .

Note, The clunk was not always there, seemed be when I backed up than went forward, Or slowed in gear before stopping,
You could feel the clunk, I thought it was the clutch, but at
70k miles I thought that I would do the "U" joints & carrier bearing first, Clutch still ok... at 83K Miles.

 

[WKellam]

The main cause of the problem is the slip joint of the front yoke binding on the output shaft of the transmission. There was a TSB circulating about in 04 that had us pulling the shaft and lubing the slip-yoke and splines with "special" grease. If memory serves, it was from GM and cost about 400. 00 (I AM NOT KIDDING!) for a 1 pint can of the stuff! BUT it worked!Obviously, you don't need and entire pint, but if I can find my can f the stuff, I would be glad to repackage it into convenient quantities to do the repair. As for U-joints, it goes without saying that if they are worn, the should be replaced first and the truck rechecked prior to lubrcating the slip-yoke.

 

[Southbound]

TDR Brethren-



My buddy has a 2008 Mega-cab with the same symptoms yet his truck is an automatic?? Do you think it is a u-joint issue?? Note: The clunk is so freakin loud you would think he was parked on a major hill!!! Let me know your thoughts and thanks!



Southbound

 

[duraman03]

Well I pulled the drive shaft and put a little grease on the splines. No more clunk. Just want to find a permanent fix.

 

[JApol]

TDR Brethren-



My buddy has a 2008 Mega-cab with the same symptoms yet his truck is an automatic?? Do you think it is a u-joint issue?? Note: The clunk is so freakin loud you would think he was parked on a major hill!!! Let me know your thoughts and thanks!



Southbound

Yes have your u-joints looked at. I was speaking from experience with my last post. Both u-joints on the rear shaft lasted about 40K. I replaced both u-joints and 8K miles later I had to replace the rear one again. Once I got that replaced I went to a driveline shop, dropped the drive shaft and had them balance it for $50 and I was a happy camper again. The shaft started at about . 2" and was balanced down to . 02".