The Clunk that was Not the Drive Shaft Slip Yoke - Solved

[Joseph Garcia]

I've had a clunk in my 07 Yukon XL Denali, since I bought it as-new-to-me, and I have finally solved it.

Whenever I was stopped and pushed the accelerator pedal, I would hear/feel a clunk somewhere under my seat. Similarly, whenever I was slowing down, and the transmission downshifted, I would hear/feel the same clunk. I went out of my way to avoid the situations that led to the clunk, so as not to create any potential further damage, until I found out the source of the clunk.

I had thought that the cause of the clunk was the drive shaft slip yoke, as suggested by members of this Forum. As such, I purchased a new nickel plated slip yoke and two new universal joints for that drive shaft, and I had them installed by my local mechanic. Unfortunately, after the installation, the clunk was still there.

Further inspection of the entire drive train and support structure revealed that the bushing assemblies on one of the front differential support mounts were badly worn and required replacement. As such, I had both front differential support mounts and all 4 bushing assemblies replaced. After the installation, the clunk was not longer there.

Our knowledge base for clunk causes and resolutions has been increased.

 

[JonnyTahoe]

Thanks Joe for doing the testing and your pictures are great too. I have a similar issue in my 2WD so I think I will replace the Slip Yoke and hope that's it. I bought a extra Drive Shaft from a Parts Recycling yard in Rancho Ca.the Slip Yoke was all rusty from being stored outside in the rain.

 

[Rocket Man]

Awesome Joseph, thanks for sharing.

 

[Joseph Garcia]

Thanks Joe for doing the testing and your pictures are great too. I have a similar issue in my 2WD so I think I will replace the Slip Yoke and hope that's it. I bought a extra Drive Shaft from a Parts Recycling yard in Rancho Ca.the Slip Joint was all rusty from being stored outside in the rain.

I purchased my new nickel plated slip yoke and two HD universal joints from Fort Wayne Clutch and Driveline, very knowledgeable folks. I provided them with the part number on my drive shaft, and they selected and shipped the correct parts for that drive shaft to me.

 

[JonnyTahoe]

I purchased my new nickel plated slip yoke and two HD universal joints from Fort Wayne Clutch and Driveline, very knowledgeable folks. I provided them with the part number on my drive shaft, and they selected and shipped the correct parts for that drive shaft to me.

We have a Driveline Specialty shop not far from me been around since the 80's. I have dropped off drive shafts before they can replace,balance,straighten and fabricate anything. Nice to have those guys around.

 

[swathdiver]

Good hunting Joe! Those might be acting up on mine, have to take a closer look. Thanks!

 

[Big Mama]

Nice work.

 

[JimHanus]

I had a "delayed" klunk once. I would hit the brakes, or accelerate, and would get a klunk after about 1/2 second. Turns out there was a front tow plate mounting bolt rolling around inside the frame crossmember. It would roll front and back and hit the metal frame. Cheap fix!

 

[avalonandl]

I have a clunk that I have address at some point.

Do you need to put it on a lift to inspect the front diff. bushings?

 

[denalianyone]

I purchased my new nickel plated slip yoke and two HD universal joints from Fort Wayne Clutch and Driveline, very knowledgeable folks. I provided them with the part number on my drive shaft, and they selected and shipped the correct parts for that drive shaft to me.

Did u replace the rear yoke as well with a nickel plated one?


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