mattwehrwein

<!--GALLERYINCLUDE-->1997 K-1500 350 4L60-E rear end 3.42 gearings i think

I put a new tranny in my truck and finnished it las weekend. the truck is running great at low speeds up to around 40 45 miles per hour.

Once i get around the neighborhood of 50 mph my truck seems like the drive shaft is jumping or something isnt catching in the rear.

It will kind of stay at the same speed for a couple of seconds while im accelerating and klunk take off.

While i had it in cruise at 55 it did the same thing periodicly.

Im hoping it's just a driveshaft of U-joint issue and not the tranny or rear end Even though my rear end has a preaty good backlash clunk evertime i take off but its had that since i bought the darn thing.

The front driveshafts U joints are not set right at this time but im not using 4 wheel drive so that wouldnt do it would it??????

Any thoughts??????????

racerx55

either transmissions pump is weak, or the cross shaft in the rear diff has seized to a spider gear and worn itself half way through the diff case. did it do it before you changed the trans or not? i would suspect the most recent "new" part.
does that year have a detent cable? or is it all electronic trans.
have you tried shfiting it out of overdrive and driving in 3rd to see if it still does it?

suzuki-guy

Two things I owuld do first change rear shaft u joints, then take diff. cover off and inspect for broken spider gear, abnormal wear, then replace gasket and fluid and see how it drives. If that does not fix it report back to us and we willl go from there.