Engine/Transmission (1994 - 1998) Shutter / Loping under load

[Gio]

I have a 97 4x4 3500 5sp

For some time now,my truck has had a tendancy to start golloping,shaking,jumping, at interstate speed, about 70/75.

But it is getting worse,

Just driving anywhere at about any speed the truck will start golloping,

like if, you would hit the fuel and let off repetedly/rapidly.

I have checked motor mounts, U-joints, drive shafts,

I wonder about the spring bushings

I also wonder about the clutchs in the rearend.

How do you know when they wear out?

 

[Matthug]

Check your fuel pressure. I had some bucking when my overflow valve went out but it could be any fuel restriction. You could also be sucking air into the fuel system, check for leaks.

Wouldn't be rearend, that would only affect it when going around turns. When going straight the clutches are not even being used, both axles are turning at the same speed. You know they are worn out when it doesn't posi anymore!