Have you checked there is enough oil in the box? I have heard that can cause the car to jump out of gears.
The movement for 1st and 2nd is longer just because of the design of the linkages.
I have fiddled with the shifter on M20s so much over the last few years. Ever since i destroyed my Rare Spares shifter about 2 years ago, its had been an ongoing nightmare of trying to fix the shifter and putting mates shifters in, untill i stuck the Celica box in middle of last year.
I was taugh when setting up the shifter on the box, first adjust the reverse linkage, so that the reverse gate lines up perfectly with the fixed gate and that when you pull the gear lever back from being in reverse it should pop back into neutral without you having to pull the lever across.
When setting up 1st and 2nd adjust the linkage till the 1st and 2nd gate lines up perfectly with the fixed gate. Then adjust the 3rd and 4th linkage to line up with the 1st and 2nd and the fixed gate. The gear lever should move easily from side to side in the neutral position without moving forwards or backwards to line up with the gates.
Also double check the nuts that hold the linkages on the side of the box are done up tight enough. I had a problem adjusting the 3rd/4th linkage one time and the nut was a little loose.
Good luck with it man.
Steve
Edited by 73LJWhiteSL, 19 February 2007 - 02:07 PM.