Rear-end popping / clunking

[Hantke]

I've noticed while under heavy acceleration I hear a series of "pops" or "clunks" coming from the rear end, this happens both while turning, or going in a straight line which makes me think its not the rear end locking / unlocking, but i'm new to these newer trucks, when i brought it in-to the dealer they actually replaced the balljoints (apparently those were about to go out) for free, but said they found nothing wrong in the rear end and a friend of mine went under the truck and said the U-joints and driveshaft seem to be okay. I've also found from research that the slip-yoke may need to be greased, and they have a service announcement regarding upgrading to nickel-plated drive-line components, could any of these be the issue, or has anybody had an similar experiences?

I've also been told its just because these rear-ends are loud, but that definitely doesn't sound right to me, also, this only happens when going from a stop or really slow speeds (under 5MPH).

 

Thank you in advanced!

 

 

2004 GMC Sierra 2500 HD

lifted via Torsion bars by previous owner (not sure if this could have anything to do with it)

6.6 LLY

[Formulabruce]

Good chance if front was lifted, the back may have been changed, especially the pinion angle. Check for shims under the FRONT of the leafs where they bolt to the rear end perches. Sometimes lifts can make U joints bind, so that is why the angle is adjusted. Just something to check..

[Hantke]

Good chance if front was lifted, the back may have been changed, especially the pinion angle. Check for shims under the FRONT of the leafs where they bolt to the rear end perches. Sometimes lifts can make U joints bind, so that is why the angle is adjusted. Just something to check..

Thank you! I will have to go check that out, that would very well make sense, i'd assume if someone just cranked it up instead of doing a "real" lift that they might not have thought it through that far forward, or maybe took their lift off when they traded it in and it wasn't adjusted back.

[cfitz]

Check the torsion bar mount bushings. Another slightly common issue with these trucks

[Hantke]

awesome, thanks! There are indeed almost-new (compared to the rest of the stuff) shims in the rear leafs, do you know whats stock?

 

I'll have to get into those bushings soon aswell. I had to have the front balljoints replaced when i bought the truck in July, and leaving the parking lot it made another balljoint sounding pop again, so I'm going to have to get that figured out aswell.

[Hantke]

Passenger side:

 

Driver side

 

 

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[Formulabruce]

Those are just anti squeak cushions. I was speaking of something right at the axle mount on the front side , and under the mount, which might be lifting the front end up in front.

[joefuskie]

I've been getting an increase in clunking in my rear end under similar circumstances. I climbed up under the truck with my torque wrench to check the u-bolt tightness and my driver side was a little loose. I took about 1/4-1/2 turn of slack out of the ones on the drivers side. The passenger side just needed to be snugged up. Still get a little bit of a clunk but it's a lot less than it was. It was a cheap fix and worth checking.

 

 

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[Tattooo]

I've been getting an increase in clunking in my rear end under similar circumstances. I climbed up under the truck with my torque wrench to check the u-bolt tightness and my driver side was a little loose. I took about 1/4-1/2 turn of slack out of the ones on the drivers side. The passenger side just needed to be snugged up. Still get a little bit of a clunk but it's a lot less than it was. It was a cheap fix and worth checking.

 

 

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Dealer has my truck for this gli5ng on 6 weeks......tightened, swapped, replaced etc etc half the damn truck.....I find out in a day or so if tbe entire rear swap did the trick....if not I told them I'm starting the buyback / lemon law process

[joefuskie]

Sounds about right for a stealership! They may never figure it out

 

 

2000 Silverado 2500

260,000+ miles

6.0l w/ cat-back Billy Boat exhaust

285/75-r16 (33x11.2) GY Duratracs

CB radio, Pb component speakers,10-inch sub

[Hantke]

Thanks! I didn't realize those were anti-squeak cushions, I'll have to get back down there and look more closely at where it mounts to the axle then, thanks!

 

I also noticed the popping from accelerating and turning left came back when I brought my front tires up from 55-75 PSI, last time I had this issue they replaced all the ball joints, and that was only about 4 months ago, they wouldn't already be bad, would they?

[Tattooo]

Thanks! I didn't realize those were anti-squeak cushions, I'll have to get back down there and look more closely at where it mounts to the axle then, thanks!

 

I also noticed the popping from accelerating and turning left came back when I brought my front tires up from 55-75 PSI, last time I had this issue they replaced all the ball joints, and that was only about 4 months ago, they wouldn't already be bad, would they?

No way they are bad in 4 months

[Hantke]

That's what I thought, I've had vehicles with 200K vehicles still using original ball joints, but I'm new to these trucks so I wanted to check first

 

 

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[BlackZ71Silverado]

Are you 100% positive it's coming from the rear of the truck???

Have you checked your sway bar end links and bushings? Sounds like the sway bar may be making the pop noise you are having. With bad bushings and/or end links, it would cause that "pop" when accelerating and turning due to the suspension loading and unloading.

 

 

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[Hantke]

The popping when accelerating sounds to be more from the rear, but can be felt on the passenger floor board, the popping when turning is definitely on the front passenger side area.

Thanks for another idea! I'll have to check the sway bar bushings while I'm checking the torsion bar mounts, hopefully I'll have some free time during the day and I can get this figured out.