Hey guys - I'm having some problems with a NV4500 in my '95 Tahoe. Seems that after I've driven it for awhile and it's good and heated up, I have a very difficult time getting it to shift into First and Second gear during stop & go driving. It has no probs otherwise, you think it could be full of 90 weight or similar, instead of the GM oil it's supposed to have? Or is this a clutch issue.. Just wondering if anyone else has run into this problem. I've driven it for probably 6 months now, and it's just started this problem as of late. Also, what size is the filler bolt on this trans? It seems to be about a 5/8 hex head???? I live far enough from a real parts store that I would prefer to get the right tool the first time! Figured the experts here would know a lot more than the 18 year old rice rocket fan working behind the counter!! Thanks ahead of time!