3/4 synchro

66fs said
1. Just use 90 wt gear oil, it is fine until it get to -20 degrees
2. Did they replace the countershaft and needle bearings in the cluster gear? This puts everything back in the right relationship. Did they really rebuild the trans???

AJ/FormS said
It almost sounds like you're not declutching far enough and making the brass work overtime.
Or possibly the oil is too thick,too thin, or wrong type. If you are using synthetic, get rid of it.And we don't need 140wt up here; I run 50/50; ATF/80-90 EP.
If your slider is new, you just need the brass rings...... and maybe not even those.

If you lived next door.....I could fix you up in a jiffy.

I'm running 80w/90 as well.Your right, it was not a complete rebuild as the repair order reads like this: 3/4 synchro assembly,gasket kit,seals and labor.As for shifting I have had several people drive it and all noticed the same issue. It was the tranny shop that said it was definitely a synchro problem when I took it back to them so they just replaced the synchro assembly the second time. Maybe it's time to try another shop!