Jumping out 4

Has it got a Landrover engine in it or an aftermarket conversion which is out of alignment? Without stripping the box again it would be hard to diagnose the fault but possibly dirt in the selector shaft/detent spring hole, if you have changed the bearings, have you missed the spacer in front of the 55714 or at the mainshaft rear? Is the output gear seated fully on the mainshaft and the nut fully tight. You may be better to fit the later input shaft, 3rd mainshaft gear and synchro assembly as the engagement dogs are angled to keep them in gear.

Martin

Ashcrofts are very clued uup and have a good FAQ... dunno if it includes this issue but they may know if you drop them a line.

Lee D