Chevy and GMC Duramax Diesel Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
I have a 2007 LBZ an I am having an issue where my driveline clunks ONLY when I’m decelerating. I drive thro a lot of mountains an it’s getting really annoying cause it will clunk often. Maybe 2 or 3 times down a short hill. It sounds like it’s coming from the driveshaft or differential. I just put a brand new driveshaft in with a new pinion yoke. It started doin it after I got the new driveshaft in. Also the truck seemed to slip out of gear or where it felt like the diff was slipping. Each time it did that it sounded like my turbo boot blew off. Only lasted for about a second then it engaged again an it was like normal. Also when I engage 4x4 while driving it clunks pretty bad when it engages. Have to stop to engage it so it doesn’t sound so terrible. Any help would be greatly appreciated cause I can’t figure what is making that clunk while I’m driving.
 

·
Registered
Joined
·
177 Posts
Pull the drain plug on the transfer case and see what the fluid looks like.
You might have a broken tail shaft retaining snap ring. This will cause the transfer case tail shaft to move in and out causing the clunking.
 

·
Administrator
Joined
·
1,183 Posts
Why was the driveshaft and pinion yoke replaced? How much of the driveshaft slip yoke is sticking out of the transfer case?
 

·
Registered
Joined
·
9 Posts
Discussion Starter #6
Pull the drain plug on the transfer case and see what the fluid looks like.
You might have a broken tail shaft retaining snap ring. This will cause the transfer case tail shaft to move in and out causing the clunking.
I had the transfer case replaced about 3 months ago an about a month ago I was in for an oil change an he said the transfer case oil needed to b changed as well. Is it normal to need new oil after only 7000km on it. The transfer case was used btw. I’ll see if I can check the oil later tonight an get back to u on that.
 

·
Registered
Joined
·
177 Posts
The drain plug has a magnet. See what it is holding.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #8
Why was the driveshaft and pinion yoke replaced? How much of the driveshaft slip yoke is sticking out of the transfer case?
I replaced it cause the old one had a dent in it an the pinion yoke was worn out so it cause a vibration in my truck at higher speeds. Procrastinated too long with replacing it an I ended up breaking my Tranny mount, Tranny tail housing and somehow wrecked my transfer case. Rather expensive to fix specially when it breaks down 8 hrs from home.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #9
I replaced it cause the old one had a dent in it an the pinion yoke was worn out so it cause a vibration in my truck at higher speeds. Procrastinated too long with replacing it an I ended up breaking my Tranny mount, Tranny tail housing and somehow wrecked my transfer case. Rather expensive to fix specially when it breaks down 8 hrs from home.
Forgot to mention the yoke sticks out about 2 inches from the transfer case
 

·
Administrator
Joined
·
1,183 Posts
I replaced it cause the old one had a dent in it an the pinion yoke was worn out so it cause a vibration in my truck at higher speeds. Procrastinated too long with replacing it an I ended up breaking my Tranny mount, Tranny tail housing and somehow wrecked my transfer case. Rather expensive to fix specially when it breaks down 8 hrs from home.
Gotcha.
Forgot to mention the yoke sticks out about 2 inches from the transfer case
That sounds about right. Just thinking that maybe the shaft was the wrong one, causing the yoke to be too far out on the transfer case output shaft which would cause some play and noise.

Some clunk noise is pretty typical on these trucks so as long as your fluids are all up and clean, and there isn’t any excessive play in the driveline, you might have something going on inside the t-case. That would explain the change in the concern when using 4WD.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #11
Gotcha.

That sounds about right. Just thinking that maybe the shaft was the wrong one, causing the yoke to be too far out on the transfer case output shaft which would cause some play and noise.

Some clunk noise is pretty typical on these trucks so as long as your fluids are all up and clean, and there isn’t any excessive play in the driveline, you might have something going on inside the t-case. That would explain the change in the concern when using 4WD.
Well the thing about the 4x4 clunk was there with the previous transfer case as well. I was hoping it would’ve fixed the clunk after I got a fresh one but it was still the same thing. Any ideas why it might be doin that??
 

·
Registered
Joined
·
9 Posts
Discussion Starter #12
The drain plug has a magnet. See what it is holding.
There wasn’t anything on the drain plug as far as I could tell but the oil was black. It hasn’t even run 3,000 km on that oil yet. Any ideas why it would be so dark that soon.
 

·
Registered
Joined
·
295 Posts
There wasn’t anything on the drain plug as far as I could tell but the oil was black. It hasn’t even run 3,000 km on that oil yet. Any ideas why it would be so dark that soon.
Because they probably charged you but didn't actually change it. Anyone else thinking about axle wrap? Do you have factory Ubolts on your rear leads? Have they ever been opened or changed? Do you still have your OEM block on top of the axel?
 

·
Registered
Joined
·
9 Posts
Discussion Starter #15
Because they probably charged you but didn't actually change it. Anyone else thinking about axle wrap? Do you have factory Ubolts on your rear leads? Have they ever been opened or changed? Do you still have your OEM block on top of the axel?
So I messed around with the Ubolts back last winter and took out one block to drop the truck in the rear. There is still an OEM block on top of my axle an I ended up reusing my Ubolts. I’ll check them out see if anything is loose back there.
 

·
Registered
Joined
·
295 Posts
I always like trying to start simple

First confirm the block is still properly seated/tapered. Also confirm its still seated properly. Then confirm the ubolts are still straight and tight. There is also a center pin through the block remember.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #17
I always like trying to start simple

First confirm the block is still properly seated/tapered. Also confirm its still seated properly. Then confirm the ubolts are still straight and tight. There is also a center pin through the block remember.
Hey thanks for the tip. I’m planning to tear into the truck an hopefully track down that clunking noise an I’ll check out the rear axle while I’m at it as well.
 
1 - 17 of 17 Posts
Top