2000 Silverado - noise [video]

GMC-AT · October 28, 2018

2000 Silverado - 5.3 (stock)

I have a low speed whining noise coming from underneath. I jacked up the truck today and spun each tire, it's coming from the back tires only.

When I spin either back tire the noise sounds like it's coming from the transmission or transfer case area. I thought it was the brakes when I first started hearing it. But once I jacked it up...it appears brakes are not making the noise. Noise goes away after 25mph or so....

Any ideas? See video below.

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GMC-AT · October 28, 2018

any ideas?

carkhz316 · October 28, 2018

Is the driveshaft turning at all during this or is the opposite wheel spinning in the other direction?

GMC-AT · October 29, 2018

Drive shaft spins...I noticed that. I only had the one rear tire jacked up...don't know if other tire would spin..

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rjgti · October 31, 2018

my first guess would be a u-joint

GMC-AT · October 31, 2018

Yes, I was thinking that could also be the case. But all U Joints were just replaced about 6 months ago. Defiantly not the back U Joint

GMC-AT · November 9, 2018

just an update - for fun I sprayed some PB blaster on the u joints and the slip yoke. The noise has stopped. I'm thinking the noise was coming from the front of the driveline... so the issue has to be the slip yoke making that screeching sound.

Make sense once I think about it more because I had the slip yoke replaced not long ago with a new one to reduce the drive link "clunk" these trucks are famous for. It did help the clunk.. but it seems this noise may have started not long after that.