will not shift into overdrive
If it is a trans issue and 4th gear, then I would suspect that maybe the adjustment for the band might be a bit off or a sticking 3-4 shift valve. Bands do stretch so if it was not build on the tight side then this may be why you are seeing this issue with the miles on it. I would suspect that the band might still be good because you have 2nd gear.
If this is a lockup issue then there are a things that could cause this outside the transmission. However if you we not having any issues prior to this then it is possible that maybe you have a bad torque converter clutch or an internal transmission issue. The thing is it needs to be properly diagnosed. Get in contact with whomever you purchased this trans from and see what they would like you to do. Best of luck. Vince


