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Funny Bucking, Missing Feeling From A Stop

Marshrat

By Marshrat
in Ask A GM Technician

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Marshrat Enthusiast

Marshrat

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Posted

The wife said our 99 Tahoe LS was missing when she came home yesterday. I looked at it and checked the codes. All looks good, no codes. When the truck is in forward gear and you let off the brake, you feel a bump bump bump until you get going. I don't feel it at road speeds yet. I don't feel it when in Reverse. Checked the transmission fluid, driveshaft, U-joints. They all look good. I am totally at a loss as to what could be causing this. Any ideas?

golfballs Enthusiast

golfballs

Posted
Posted
The wife said our 99 Tahoe LS was missing when she came home yesterday. I looked at it and checked the codes. All looks good, no codes. When the truck is in forward gear and you let off the brake, you feel a bump bump bump until you get going. I don't feel it at road speeds yet. I don't feel it when in Reverse. Checked the transmission fluid, driveshaft, U-joints. They all look good. I am totally at a loss as to what could be causing this. Any ideas?

 

 

I dont know if this is any help but i had a simular issue last year with my 2000 g2500. When i took off i felt a bumping/banging from my floor and thougt it was a mount. I inspected it and found out the the exhaust was banging underneath. I took off the exhaust and found that my muffler was clogged with the remains of my cat converter. I never got a code for the converter. I shook a lot of converter debris out of the muffler and reinstalled it and i nolonger had the bumping/banging sound. that is what i experienced and dont know if that is your issue.

Marshrat Enthusiast

Marshrat

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No, don't think I have the same issue, but thanks though. I took the diff cover off and checked the gears, they look Ok for 150k miles. Only a small amount of fine material on the magnet. I rechecked the U-joints. I jacked the rear end up and put it in gear and observed the gears and driveshaft at around 10-15mph. Nothing looks bad. I put it all back together and went for a ride. Now it won't do it. It is fine now. WTF??

Guess we'll just drive it until it does it again.

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