AO Platinum Member
Join Date: Aug 2003
Location: London, England
Re: ATF in a manual transmission
If you already have broken gear teeth then you probably need to think about finding another gearbox!
As for which oil to use, some manual gearbox are spec'd to use ATF fluid instead of gearoil.
One point to remember about types gearoils in synchro gearboxes is that extra slippery is not always what you want because the synchros need friction to work.
So if it is spec'd for a GL4 gear oil do not use a GL6...
Some topspec ATF fluids meet the GL4 standard too (i.e. Redline D4 ATF, but that costs over £12/L...!)
Many years ago I made the mistake of using GL6 gearoil and Molyslip in an Audi Coupe gearbox, it was like the synchros were no longer there... it was dreadful!
Audi TT 3.2v6 DSG
xAlfa 156 Selespeed sp3 + Brembo conversion
Fiat Cinquecento 899cc