Low speed rear noise??

[Buc22]

I have a rhythmic light clunk/thump coming from the rear on my 2014 Express 3500 chassis. Only when lifting off the throttle to coast at low speed 20-30 never when on the gas and if present at higher speeds when I coast cannot hear. Wife and I both agree seems to be coming from the rear under chassis on passenger side. Noise seems to be only when cooler temps and goes away after driving for awhile. Rear u-joint has 1 cap that seems to be leaking a little. Bought RT new in FEB 2016 and currently has 30700 miles but never noticed any sound till the fall and cooler temps. Noise has gradually gotten a little louder every year. I thinking about starting with rear u-joint. Anyone have or had a similar sound or advice?

[pomerlo]

From what you describe yes the first place to look at are the U-Joints.

[Buc22]

Originally Posted by pomerlo

From what you describe yes the first place to look at are the U-Joints.

Thanks as a backyard mechanic it always helps to get some advice! Have to wait for about a week to rain, but will post update.

[booster]

Originally Posted by Buc22

Thanks as a backyard mechanic it always helps to get some advice! Have to wait for about a week to rain, but will post update.

I would agree u-joints are prime place to start. Also be sure to check the yoke to the transmission for sticking splines, as there have been some issues with GM trucks and sticking splines that make odd noises. Be sure to drain the transmission if you pull the yoke out or be quite severely nose down.


Forgot about the two piece driveshaft, so you would have two spine joints but the one on the trans wouldn't move much.

[pomerlo]

These video might help for diagnosis even if it is not a GM van.

https://www.youtube.com/watch?v=c6-IQ8Gxmdw

https://www.youtube.com/watch?v=5gOeBE-ylQw

Good luck

[Buc22]

Originally Posted by pomerlo

These video might help for diagnosis even if it is not a GM van.

Good luck

Wow thank you on the video! This one is the closest rhythmic sound to mine and I have sampled about 20 u tube videos looking for anything to sound close to what I have now I am almost certain it is my rear u-joint. This week is rain in Texas so I'll give update when weather clears next week to all that were so kind to help me narrow this down.

[Buc22]

Anyone have any experience with the GM 3R (S44) U joint with the plastic injection?

[Juliem]

Heard a similar noise, but mine was high pitched. Stopped after running for awhile. It was failing wheel bearings (which turned into busted axle).
2008C190P, 150,000 miles

[Buc22]

Originally Posted by Juliem

Heard a similar noise, but mine was high pitched. Stopped after running for awhile. It was failing wheel bearings (which turned into busted axle).
2008C190P, 150,000 miles

Thanks for the info!
Got brakes up 1st then weather permitting will try rear joint then passenger side rear bearing. RT will not fit in my garage too tall so I must work on it in the driveway. Will update when I hopefully fix.

[Buc22]

Update noise ended being Pinion Bearing and spider gears so I ended up having rear diff overhauled with all bearings and spider gear replaced.

[RAA357]

I had the Ring and Pinion set go bad in my 2007 RT 210V a few months back. Without getting into the details Chevrolet replaced the drive shaft, ring and pinion gear set, labor for free. I paid to have new axel bearings and seals installed. If you go and look into the forums referencing The problem Chevrolet had with the Rear ends in certain model Chevrolet Express models you can get an idea of what caused the issue.

[Buc22]

Originally Posted by RAA357

I had the Ring and Pinion set go bad in my 2007 RT 210V a few months back. Without getting into the details Chevrolet replaced the drive shaft, ring and pinion gear set, labor for free. I paid to have new axel bearings and seals installed. If you go and look into the forums referencing The problem Chevrolet had with the Rear ends in certain model Chevrolet Express models you can get an idea of what caused the issue.

Would love to read this but I cannot find it? Curious as to why my 2015 with ony 30900 miles would need a diff overhauled?

[booster]

Originally Posted by Buc22

Would love to read this but I cannot find it? Curious as to why my 2015 with ony 30900 miles would need a diff overhauled?

It would be of interest to see what axle in your van in 2015. It may have a tag on the driver side axle tube, facing the rear that should say if it is a Dana or AAM built unit. I think by then it would be an AAM or might be shown as GM. The 2007 issues, which we had also on our 2007 190P, was a Dana 60s axle. Both axles are probably undersize for the class B van at 9.5 and 9.75 inches ring gear, even though rated for it. 210s in particular will be even harder on them with the higher rear weight.