Crunchy 1st To 2nd

[TuneR32]

Thanks in advance for anyone who can help me with this one . . .

Story is, gearbox rebuilt by someone who is apparently very good after metal shavings were found in the oil. Everything in the box was replaced except the actual gears, and good quality oil (redline i think) was used in the box. Clutch was also replaced with standard twin plate (unsure of brand).

Car has had engine rebuild with upgraded power, 350kw from 240kw.

Took delivery of it yesterday, and theres a problem changing 1st to 2nd, and 2nd to 3rd. 1st to 2nd is worst, and its worst when the engine and drivetrain are warmed up.

Even on slow changes, theres a grinding of gears between changes. Doesnt happen on the higher gears, only on the lower ones. Double clutching it stops it, it is worst when the chages are fast or under power.

It feels like the gear doesnt completely disengage when changing, or like the synchros arent meshing properly. I can feel meshing gears through the stick, and it feels like they are still spinning when the clutch is in, and then they have to slow down and reengage in the next gear.

The master cylinder was recently rebuilt, and the slave looks like its not leaking.

Any ideas?

I am wondering if the synchro is somehow wrong, or if the clutch isnt disengaging properly.

Dont know how to go about diagnosing it though.

[bozodos]

if its a RB20 box then very likely its soon going to completely shatter a gear and you'll have to get it towed with you holding the clutch in the whole way. I know this because I've seen it happen 3 times in 3 different cars with the RB20 box. They aren't very strong at all, and second gear crunching seems to be the start of the hassles, like 4th in mine does

[cuppas]

yeah i wouldnt drive it in that condition

get it towed to the mechanic, have him take it apart and take a look at it with you there

if you dont trust your mechanic haha