I have a 1994 GC Laredo, 135K miles, automatic trans. Runs and drives great (actually one of the better vehicles I've ever had over the years).

Starts, runs drives without issue except for one oddity. Here's the problem...

As I accelerate and get to 32 MPH there is a slight shudder until I pass about 34 MPH. It's there when I'm not accelerating and staying at 32-34 MPH, but not when slowing down. There is no loss of power and it's not cutting out, and at that point I'm between gear changes.

I've checked the U-joints, transmission and engine mounts, as well as wheel bearings, and other things related to the drive train and all seem to be in order. Basically, nothing bent, broken, leaking, what have you.

I'm somewhat disposed to just letting it go until something breaks, but would rather attend to the issue if I can find out what it might be.

Thoughts?

 

Something internal in the trans?

 

Have the drive shafts balanced. Make sure the front shaft is phased correctly.

 

You problem is probably the lockup converter in the tranny. Most trans shops can fix that with an additive.