# Clunking sound from rear end from stop



## VnDrWLawnCare

Hello,
Hopefully someone else has experienced this problem and can help me out. 
2004 GMC 1500 4x4

It doesnt happen every time, but close to... when taking off from a stop i get a clunk noise from the rear end. It feels like it is loose or something is moving or shifting. Has anyone experienced the same thing, and what is the problem / cost to fix.

The truck doens't even have 50,000 miles on it, and has been used to pull a 16 ft enclosed for lawn care.
Thanks for any help
Eric


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## ahoron

U joint in drive shaft would be my first guess. as far as cost about $50 for both


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## Mxrider069

I had the same thing happen I took the shaft out and filled the end that goes In the trans with auto trac fluid and it seemed to solve it. Just a suggestion


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## RBRONKEMA GHTFD

My 04 sierra did that last year. Mine was more of a squeeking though. You can do the u-joints yourself or bring them it in and have it done.


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## VnDrWLawnCare

*Thanks for the replies*

A U joint would be about the easiest and cheapest fix. If the U joint is bad, would i hear a constant sound as i go down the road? The clunk sounds pretty loud, and sometimes wonder if part of the rear end might just break off. But it is funny that it is not everytime.


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## Spitz

Like mx rider said, the splines for the slip yoke arent lubed enough, when you take off the rear end squats a little and the splines have to slip, but yours are binding and will give you that clunk.. I think they even started putting some sort of plated slip yokes on some.


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## THEGOLDPRO

i had this as well turned out my spare tire was alittle loose underthere and it was clunking around when stoping and starting.


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## dheavychevy38

Check the u-joints is the first thing to check. Then check the rear end for excessive play. Last it could be the chain in the t-case is loose. How many miles on the truck?


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## VnDrWLawnCare

Truck has less than 50,000 miles on it.

How do i check the rear end for excessive play? What is normal?


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## B&B

VnDrWLawnCare;702581 said:


> Truck has less than 50,000 miles on it.
> 
> How do i check the rear end for excessive play? What is normal?


There's nothing wrong with the rear axle, it's the slip yoke in the rear of the T-case like Spitz already mentioned. There were multiple TSB's for this issue which included an updated nickle plated yoke.

Greasing it will fix it temporarily but changing the yoke to the new design will fix it permanently.


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## 042500hd

VnDrWLawnCare;702550 said:


> A U joint would be about the easiest and cheapest fix. If the U joint is bad, would i hear a constant sound as i go down the road? The clunk sounds pretty loud, and sometimes wonder if part of the rear end might just break off. But it is funny that it is not everytime.


You can check for play in the driveshaft, but just because there is none does not mean the joints are good. I just replaced them on my 07' no play at all. Once i got them out though I could see one cup had no bearings left at all. Cost me $10 for the joint and took about a 1/2 hour to do. All my noise is gone now. (knock on wood) I was getting the same clunk or tick as you when shifting as well as a strong vibration above 55mph. Some noise is normal though when shifting on our trucks. But if you're sure it wasn't there before u-joints is where I'd start.


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## dheavychevy38

You never know and it doesn't hurt to check i have seen everything from pickups to semis come from the dealers with no oil in them and then out of no where am the give out. I know they have had lots of tsb on those things but i have also seen u-joints that when in the shaft make it feel good and tight but when removed all those parts inside with no grease become powder. To each his own.


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## VnDrWLawnCare

*Thanks for the replies*

I dont have any vibration or noise at any speed. The only noise i have is when taking off from a stop. Sounds like the slip yoke by what i am reading and understanding.

Any idea on cost to fix that slip yoke to a new design?

I appreciate everyones help.

Eric


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## B&B

VnDrWLawnCare;702970 said:


> I dont have any vibration or noise at any speed. The only noise i have is when taking off from a stop. Sounds like the slip yoke by what i am reading and understanding.
> 
> Any idea on cost to fix that slip yoke to a new design?
> 
> I appreciate everyones help.
> 
> Eric


Like I said, in your case/description the updated yoke will fix it. Very well known issue with these trucks.

The updated yoke will run you around $120...plus an hours worth of labor if your paying.

Yoke is GM p/n 12479383


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## VnDrWLawnCare

Thanks for all your help.

Going to get the transmission fluid changed Wed. They said they would also look at the rear end and fix that as well. Common issue he said.

Eric


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## Spitz

If you dont know for sure have them pull the rear shaft and check the u-joints and just lube the splines right away, if you notice the noise is gone after reinstallation maybe think about the plated slip yoke when its time to change out the u-joints..


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## Bigcat99

Ive been having this issue myself lately and have an appointment to get my 04 1500 CC in the shop to be checked out this Friday.


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## livetoplow

Hi i have this same problem in my Silverado 2500. I checked the part number but only seems to be working on other sites and not GMpartsdirect. Is this the correct part number for my truck ?

12479383 
2000 Chevy Silverado 2500 4x4 with the 6.0 Motor 

Im sure B&B can chime in on this for sure since he seems to be the ultimate Chevy guy on the forum

Thanks


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## Newdude

livetoplow;1226844 said:


> Hi i have this same problem in my Silverado 2500. I checked the part number but only seems to be working on other sites and not GMpartsdirect. Is this the correct part number for my truck ?
> 
> 12479383
> 2000 Chevy Silverado 2500 4x4 with the 6.0 Motor
> 
> Im sure B&B can chime in on this for sure since he seems to be the ultimate Chevy guy on the forum
> 
> Thanks


That number you posted according to the bulletin is for 1500 silverado/sierra and suvs.

What cab configuration do you have?


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## livetoplow

Newdude;1226955 said:


> That number you posted according to the bulletin is for 1500 silverado/sierra and suvs.
> 
> What cab configuration do you have?


2000 Silverado 2500 4x4 with Ext Cab and short bed

Thanks !


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## Newdude

livetoplow;1227128 said:


> 2000 Silverado 2500 4x4 with Ext Cab and short bed
> 
> Thanks !


The bulletin shows 12477704 (with u-joint) as the part number for 2500 ext. short box trucks.


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## livetoplow

Newdude;1227160 said:


> The bulletin shows 12477704 (with u-joint) as the part number for 2500 ext. short box trucks.


Hey thanks for the Part Number. I just had the U joints replaced and still i get the sound. My Mech. seemed to be clueless then i read this thread. Only happens when i stop and take off or hit a big bump. Its a small clunk and it almost sounds like i am tapping my horn once real quick. Like a quick honk. The honk noise happens when it clunks. I am guessing it is related. My horn has not worked in 2 years so i know its not a horn that is going mad.

Thanks !


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## jonnywong

Check to see if those spacers/cushions are gone between the leafs on the springs. Mine went and it clunks a little going over bumps/taking off/stopping.


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## livetoplow

Ya my buddy told me that his bushings in his leaf springs were gone and caused it to clunk too. It goes into the shop tomorrow a.m. so i will see what happens. Just tired of hitting a bump or plowing and when i go to stack i hear this beep/clunk sound that sounds horrible:realmad:. Like something loose. Just makes the truck sound like S#$%.

Just something my Mechanic sound have found when it was in there for the U Joints. Damn near impossible to find a good Mechanic around my way.


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## Daveyboy32

I have the same problem on a 2003 extended cab 2500 HD.Sometimes Clunks on start up and once in a while feels like it might slip a little. The letter T was used in stating there is a modified yoke. T is transmission or transfer case.


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