Thread: Gearbox problems SIII, Advice needed

1st up, series boxes SHOULD run 90w GL4 gear oil (most standard gear oils are GL5 rated). Running a GL5 oil MAY cause excessive wear/deterioration of the phosphor bronze parts over time.

However - not related to the current problem.

How much actual clutch depression is he getting at the pedal - i.e. when you press the clutch, you can feel when the slack/freeplay is taken up. After that, you need a good few inches of travel with a solid pedal.

Sounds very strange, it really sounds like a clutch problem. But the change to 4th should be pretty easty even without a clutch.

It could be a selector issue (easy to check - just need to remove the box top cover) - but that wouldn't explain the crunching...

Clutch is releasing OK pedal travel adjustment spot on, I told my son to check the gear change mechanism and selectors first for any signs of wear, do you think ATF in my box would cause any problems, I'm wondering why the previous owner used ATF, Regards Frank.

Originally Posted by Tank

Clutch is releasing OK pedal travel adjustment spot on, I told my son to check the gear change mechanism and selectors first for any signs of wear, do you think ATF in my box would cause any problems, I'm wondering why the previous owner used ATF, Regards Frank.

I don't know why he would use ATF - maybe he thought it would help the synchros. Rick is the expert, but ATF is AFAIK about the same as running 70W75 or similar oil. Some ATF is GL4.

I tried VMX80 in my IIA, didn't make much difference and didn't help the oil staying where it should (the series selector mechanism isn't the best at sealing).