I've got another trans problem. I just got the car together and tried test driving it. The trans slips in second and third gear. These are the facts:

1. the trans is newly rebuilt with a transbrake (need to press button for reverse).
2. I've got reverse gear therefore transbrake solenoid works.
3. it goes OK in first gear but, based on acceleration and rpm, I think it's really in second gear. Another reason I believe this is because the transbrake ,which only works in first gear, doesn't work.
4.I checked the external linkage and it's correct. In fact, I put the car on jack stands, disconnected the linkage and put the trans in first gear and the transbrake still doesn't work.

Do you think it's the manual valve and linkage inside the trans? I'd like to exhaust all possibilities outside the trans before I go inside.