Gearbox jolts

[kusok]

I recently purchased my first cruiser and having read a lot of info about the 4spd auto reliability, I didn't even consider there could be issues with it, but the service center guys said that it's almost gone. I suspect something else may be wrong because everyone says the 4spd is bulletproof.

The issue I have, is that when coasting a lower speeds (below 50mph) and then lightly applying the throttle (maybe a quarter of the way), there is a jolt when the gear is engaging. The jolt is similar to the one occuring when flooring it during overtaking, but happens with much less throttle application.
Did anyone have similar issues at any point? How were they cured? I really hope the gearbox is not dying on me.

The car is a 2003 with a diesel (1HD-FTE) and completely stock at the moment.

 

[sonofshin]

Maybe drive shaft ujoints have play in them?

 

[SmoothLC]

Maybe the 100 series clunk/thunk drive shaft problem . . .

 

[phippsj]

I got the same thing on my 2005. I attribute it to worn front drive shafts.

The prop shaft clunk/thunk is a separate issue that I've cured by pulling everything apart and cleaning/lubing front and rear prop shafts, including the splines.

With 154k miles and ten years on the truck, I plan to replace the front drive shafts at the first of the year. Leaking boots probably mean the grease is mostly contaminated and the tulips are worn. No ticking yet.