clunking noise coming from ??

Question

I have an 80 chevy truck, 4 sp. man., sag transfer case, 4x4.
whenever I push in the clutch pedal, or whenever I push on the gas and let off fast, there is a clunking coming from underneath the truck. fluids are all good, what should I check next, thanks.

its a carburated small block 400, and all the mounts are fine.

It was the u-joint connected to the Tranny, and I did notice that the seal around the transfer case yoke is leaking, is this an easy fix ?

Answer 1

I would say most likely you have a broken motor mount.If one has failed the I would replace all three (one on either side of engine and one at rear of tran).Take alook at the rubber part of the mount and check for tears,it may be hard to see so use a flashlight.If in doubt change them anyway they are cheap insurance against a 27 year old rubber part failing.God bless

Answer 2

It's most likely the drive shaft U-joints. While down there look for leaks at the rear differential front seal. Any grinding or bearing noise at higher speeds?

Answer 3

check u bolts on both axles thay tend to losen over time aslo check your leaf springs at the axle thay can brake and make a sound thats kinda a clunk outher than that i could be in side your t case

Answer 4

u joints check for slop or play in them check all the tranny, transfer case and engine mounts for worn or missing bushings.

Answer 5

this sounds like a job for dr.90210

Answer 6

i dunno about the clutch but i know that letting go of the excel too fast will cause a slight thump. i guess because of the fuel injectors.