Anybody have an idea why my truck would be clunking if I let off the gas quickly? It's a 1989 with a 350 and 5 speed. I'm thinking its just differential slop but it might also be a rear tranny mount? I have no idea, any input would be great though!

Hope is not a plan. Change is not a destination.

Check it.

They are easily visible on that truck.

Man that's just a gm truck for you,every one i had just about did that.
My 88 Chevy 4x4 did it all the time,i even replaced the tranny mount and it still did it.
My suggestion would be check the motor mounts.

Differential slop, or could be a universal joint?



2004 Cavalier. Razzi. (Sold)
1998 Corvette. Some mods.
1992 Typhoon. Lots of mods.
1994 Civic VX 44MPG

check the u-joint first, take the drive shaft out just to be sure

Could be a motor mount or trans mount too maybe?


2009 Ford Mustang V6

Well I just put it new U-joints before I had the tranny rebuilt. So I figured it was just the natural slop out of an old GMC. It really only does it if I'm stepping on it kind of hard then just completely let off though, that's why it puzzles me, just shifting or letting off the gas slowly makes no noise at all.

Hope is not a plan. Change is not a destination.