swisstonihasher

Anyone out there also have a crunching sti 6 speed gearbox on 5th gear? Its not really that bad as increasing engine revs during change seems to help. I'm using decent fully synthetic gearbox oil and I've tried putting more than max to see if it helps.

Its only a minor crunch more annoying really...

scoobyboy

there are a few bullitins about the 6 spd box might be worth getting the dealer to check them out for you

JohnD

iTrader: (5)

As you are increasing revs I assume you are getting this on down changes?
Using full synthetic oil in the box may well be aggravating your situation. There has been a lot of discussion here about the experiences of a number of people with such problems when using full syn. (me included, but in my previous classic 5-speed) Changing back to a semi-synthetic fluid cured the problem!
JohnD

swisstonihasher

This is really bizzare as I've used the Silkolene Silktran SYN 5 75w90 oil in my old 5 speed and had perfect gear changes. What oil do you recommend now and use?

I used mineral based gearbox oil once in 5 speed, although upto Subaru's recommended grade, it didn't make for smooth gear changes - although didn't crunch the gear like it does on the 6 speed.

It actually wants to crunch sometimes changing up, not down! When I say "increasing revs" I should of said just keeping revs up and not letting it drop to or near idle. It's only from 4th to 5th, every other gear is fine.