Rear Driveline

I have a vibration in what appears to be the rear driveline of my 96 t-100 (6 cyl. 4wd, extracab). I'm sure the u-joint at the rear diff. is shot as I can see a bit of movement and am getting the telltale "clunk" when shifting between fwd and rev. Would this cause a vibration on the road? It occurs at approximately 35mph and around 70mph - only when on the gas, the second I get off the accelerator it goes away. My question revolves around the "carrier" or "hanger" bearing. If I place my hands on the driveline either side of the bearing and tug I can move the line as it goes through the bearing laterally and vertically a bit. Should this thing be rock solid, or is a bit of play o.k.? (Both the "clunk" noise and carrier bearing flex occur whether the rear end is on or off the ground).

I plan on dropping the whole rear driveline and replacing all of the u-joints from the tranny back to the rear diff because with my luck once of the other u-joints will go in a month or two and they aren't too spendy to purchase! Should I replace the carrier bearing as well (it has 150k miles on it)? I'm hoping the u-joints/carrier bearing will solve this and I don't have to mess with the ring and pinion in the rear diff as I'm a pretty green mechanic... Thanks for your help!

My 1993 had a u-joint go out and it did the same thing, vibration and all. I replaced my carrier bearing and all u-joints. I replaced the carrier b/c it was going bad. When you remove the shaft, spin the bearing and listen for any noises. Mine was making a grinding noise and had a slight wobble. I reccomend that if you change the carrier bearing, get the Toyota part not the aftermarket from the general autoparts stores. The Toyota part is more expensive though. I purchased the one from advance autoparts first and it was not the same part. The bearing was the same but the bolt hole and bracket dimensions were different. I checked with 3 other auto parts stores and they only carried that same one. So I ended up buying the one from the Toyota dealer.

Thanks for your input, especially the 'original part' c/b. My thinking as well - all u-joints and carrier bearing.

No problem. Good luck.