07 2500HD Rear end thunk - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BlueDiver · 08-31-2016, 07:58 PM

My 2500 has a pretty significant thunk in the rear end when rolling away from a stop. It happens so often I slowly roll forward and keep RPM down until I feel the thunk then drive like normal. Annoys the crap out of me and the poor soul behind me at the light. After searching the net it looks like this is a widespread issue.

Is there a permanent fix for this yet or is it just something I have to deal with? I've heard mixed reviews. Any help would be great!

Thanks,

Don

Deer_hunter_088 · 03-14-2017, 03:34 PM

ttt. could be u joints? or somethin like that?

slow72 · 04-01-2017, 10:41 AM

My 10 does the same thing. It started after i had the driveshaft out to grease the u-joints. I've been told it is the slip yoke in the end of the transfer case. I've removed and greased the splines liberally and it got a bit better, but still there.

KShortell · 05-09-2017, 09:41 AM

The splines on the slip yoke at the transmission and/or transfer case will do this on occasion, particularly after a hard stop. This is more of an issue on trucks with longer or two-piece driveshafts and has been since at least the 70s. There is a special, thick grease that GM uses to quiet it down. It is blue and often referred to as "Smurf" lube or something like that.

I've been fortunate that my '08 Silverado doesn't really do this. My old '86 Suburban sometimes would.

Good luck!

08-31-2016, 07:58 PM	#1
BlueDiver Registered User Join Date: Apr 2016 Location: Mobile, AL Posts: 39	07 2500HD Rear end thunk My 2500 has a pretty significant thunk in the rear end when rolling away from a stop. It happens so often I slowly roll forward and keep RPM down until I feel the thunk then drive like normal. Annoys the crap out of me and the poor soul behind me at the light. After searching the net it looks like this is a widespread issue. Is there a permanent fix for this yet or is it just something I have to deal with? I've heard mixed reviews. Any help would be great! Thanks, Don

03-14-2017, 03:34 PM	#2
Deer_hunter_088 Registered User Join Date: Aug 2016 Location: Mount Carmel Illinois Posts: 1,321	Re: 07 2500HD Rear end thunk ttt. could be u joints? or somethin like that? __________________ 1994 k1500, Oldredz71(ext shorty 4x4 6 in lift) 1998 S10ZR2 2005 Silverado 2500hd(tow pig) Made in the USA, just like my trucks

04-01-2017, 10:41 AM	#3
slow72 Registered User Join Date: Sep 2008 Location: Regina, Saskatchewan Posts: 43	Re: 07 2500HD Rear end thunk My 10 does the same thing. It started after i had the driveshaft out to grease the u-joints. I've been told it is the slip yoke in the end of the transfer case. I've removed and greased the splines liberally and it got a bit better, but still there. __________________ 1972 GMC LWB, 250, 4sp 2010 GMC Sierra 6.6 CCSB

05-09-2017, 09:41 AM	#4
KShortell Registered User Join Date: Oct 2003 Location: Chesapeake, VA Posts: 724	Re: 07 2500HD Rear end thunk The splines on the slip yoke at the transmission and/or transfer case will do this on occasion, particularly after a hard stop. This is more of an issue on trucks with longer or two-piece driveshafts and has been since at least the 70s. There is a special, thick grease that GM uses to quiet it down. It is blue and often referred to as "Smurf" lube or something like that. I've been fortunate that my '08 Silverado doesn't really do this. My old '86 Suburban sometimes would. Good luck! __________________ Semper Paratus



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