105 Gearbox issues

[mgbalfa]

Hi guys
Just fitted motor and box back into car. Motor not running as yet but just going through the gears after i replaced gear stick ,andnow  I can not select 3rd or 4th . first & second Fifth & rev ok.
It was working fine just before I refitted into car .
I have checked detent springs and bearing's all good.
Any thoughts .

[Colin Byrne]

That sounds pretty strange, its not just the engagement teeth hitting up against each other is it? Have you spun the drive shaft around and tried again?