I have a 2000 lc. The transmission was replaced 35k miles ago. It was rebuilt. It shifts fine going from 1st to 2nd. When it goes from 2nd to 3rd sometimes there is a clunk. I greased the drive shaft with plenty of moly and it goes away somewhat for the first 500 miles, but then it comes back. when It goes away i feel like the grease just covers up the clunk, but I cna feel that it is still happening. The grease just softens/insulates it. I greases is twice in the last 6k miles. The previous owner seems to have never greased it and it was dry. The truck has 170k on it. I am feeling like it might be the CV axles that have play in them. If i leave off the gas then step on it i feel like there is play in the driveline. I think when there is tension on the driveline it is fine, but when the tension from the engine lets off in the shift from 2 to 3 the play is too much and causes it to clunk. The rpms don't go up in between shifts so I feel the tranny is good. I bought new uppers control arms, cv axles, lower control arms, and Tie rod ends. I also bough new rear upper and lower control arms and new blistine shocks all the way around. I haven't installed any of it yet though. Its still being shipped in parts. Does anyone have any idea of what this clunk could be? It seems like there is play in the front end, but I am not sure.