Is it normal for stiff shifting with new synchro rings?

[crashmctavish]

Sounds like the problem was there before, stiff change may wear the forks. I think I would strip the gearbox again & make sure the various parts are size matched. By that I mean diameter clearance, assembly, roundness etc etc. Im trying to remember whether it is possible to put the synchro pawls in backwards? Dont forget a bent shift rod would cause the problem. Incorrect shims on the gears would place them in the wrong place on the shaft. etc etc. Dont forget no 2 boxes are the same & interchangability of semi worn parts can be a problem in itself.

[GTVdrifter]

Was just searching for some diff info on this fantastic forum and ran across this thread. I have noticed a problem with the aftermarket syncro sleeves that you can get from the usual parts suppliers. It is difficult to explain but, I'll try:

The syncro rings have a tapered friction face. They are symmetrical and can be installed on the gears with either way facing the sleeve. Correct factory syncro sleeves (with the engagement teeth on the inside that are moved by the forks) need to have the same angle of taper as the syncro. Think of the syncro as brake shoes and the sleeve as the brake drum. I have noticed that common replacement sleeves from the US parts suppliers are machined improperly and the angle of the taper is flatter than it should be. This results in a freshly rebuilt transmission that has drag on the syncros when the box is in neutral. The points of the teeth on the sleeve just starting to rub on the syncro. The box will not shift as smoothly as it should. It is common for mechanics to suggest that it will "break in" but, I believe the syncro will just wear prematurely to match the angle of the incorrect part. The tips of the teeth start to dig a groove on to the friction surface of the syncro as you slide the sleeve into full engagement. Once the teeth on the sleeve touch the teeth on the gear, the work of the syncro system is done.