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Old 09-24-2011, 12:36 AM   #1
chrohm
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Rear End Noise

1986 C10 Silverado bagged truck.

Bought the truck with some rear end whine at 40 mph to 60mph or so only on acceleration. Soon as I let off, sound goes away. Diff fluid is full, but looks a little dirty. I'm pretty sure this is the original rear end with no rebuild. Thinking about taking to the local diff/drive shaft shop. Does this sound like a ring and pinion issue, or do you think I'll need a rebuild? I don't have any clunking or grinding noises.

Thanks
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Old 09-24-2011, 04:09 AM   #2
INSIDIOUS '86
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Re: Rear End Noise

is it a whining howling noise? if so its a rear end about to die and rather worn
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Old 09-24-2011, 08:14 AM   #3
LONGHAIR
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Re: Rear End Noise

Quote:
Originally Posted by chrohm View Post
. Does this sound like a ring and pinion issue, or do you think I'll need a rebuild? I don't have any clunking or grinding noises.
It sounds like the ring and pinion are shot. Once they get to a wear point that they make noise, they are done. Nothing can bring them back. They must be replaced.
In most cases it is easier/quicker/cheaper to find a used complete housing. You just have to be aware of what you are looking for and what you are looking at as a replacement.

This gives you the option to change gear ratio, if you choose. But the main thing is that you "get into it", you need to see inside. This gives you some idea of the wear, confirms the gear ratio, and whether there is some kind of posi-traction unit installed.
If there is a "gov-lock" (factory Posi for those years), it is not necessarily a "deal-breaker", but don't pay any extra for it.

This is a quick bolt-in, requiring nothing more than your time, some gear lube, a gasket, and maybe some new U-bolts. It is used, so it may not last forever, but it is cheap and easy, plus you can do it again.
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Old 09-24-2011, 08:16 AM   #4
Keith Seymore
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Re: Rear End Noise

Ring and pinion mesh noise is a high pitched pure tone, around 370 Hz, depending on the gear ratio (...if that helps ).

It's pretty typical for it to light off on just coast - or just accel - or just decel.

Sometimes they are just noisey and will last forever, especially as you get up into the higher numerical ratios.

You could either run it and find out, or have it rebuilt but it's probably taken a set now and you'd need a new ring and pinion.

K
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Old 09-24-2011, 09:00 AM   #5
chrohm
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Re: Rear End Noise

thanks guys!
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