Dear all

I occasionally have problems selecting 1st gear In my 1981 Westy (manual).
The problem seems worse when the engine is warm or has been traveling in top
gear for some time.  It is more inconvenient than a problem at the moment.
I usually shift into 1st on a roll before coming to a complete stop - this
works 99% of the time.
Is this something related to the shift linkage/shifter that can be easily
fixed (it feels like you are pushing against something solid, and usually
ends up slipping into 3rd instead of 1st) or is it a synchronization ring
problem showing up.  Can I reduce the problem by using synthetic gearbox
oil?  I have no other problems with the box (doesn't jump out of gear,
selects easily on the move)
TIA
Michael
1981 Westy 'Daisy'