Dana 60 c6 transmission. From 0-25 my truck makes a weird thumping noise. Is it u joints or am I gonna have to look into the axle?

 

Two wheel drive or four? Does the sound get faster/louder as speed increases? Does it seem to come from the front or rear? Does it always do it? Does it do it more on smooth or rough roads?

The only thing I can think of with the info given so far is to check the radius arm bushings if it has them. They will make a thumping sound if they are worn out.

 

4 wheel drive stays the same then stops at 25 all roads more common when cold

 

U joint usually chatter or clunk when going into gear.....Are you running bias ply tires? Have someone ride in the bed and see if they hear it back there versus in the front end.

Have you checked your shocks for being worn out and ck the rubber shock mounts.

 

Are you missing a cat?

 

LMAO


A thumping is almost always a tire, unless something is caught up in the drive shaft, such as a small, furry creature.

 

Is it speed sensitive? Meaning, the low frequency at low speed?

Lug nuts tight?
All wheel weights present?
Wheels tightened flush to the hub?
Flat spot on a tire or any tread bulge?
.. or a tire has soft spot due to separation/delamination of the inner layers. Swap 'em front to rear and see what happens.

 

Never had any. And not tires cause it does it with another set of 33's

 

Put on my glass packs and so far runs fine. Was straight piped should have thought about compression