Gear oil

[Grahamgrot]

Hi went to check the final drive oil level, took out the level plug and about 1/3 litre of oil poured out, so is it over filled or can oil from the gearbox run into the final drive? 1975 T3 on main stand.

Cheers
G

 

[john zibell]

If the gearbox output seal is bad, oil can end up in the final drive. How is the gearbox oil level? If the rubber bellows at the cardan join is full of oil, then the gearbox output seal is bad.

 

[Grahamgrot]

Hi thanks for your reply, the gearbox oil needed about an eggcup full of oil

 

[john zibell]

Hi thanks for your reply, the gearbox oil needed about an eggcup full of oil

I don't fill the gearbox to the level plug on the old Tonti bikes. I only put in 700cc instead of the specified 750cc. The venting on that gearbox isn't great and heavy oil will stop airflow through the spring that holds the detente in place on the shift drum. With the full 750cc they are prone to blowing out seals.

 

[Amboman]

I never use level plugs on the transmission or rear drive. Drain thoroughly, measure the correct amount and fill.

 

[john zibell]

I never use level plugs on the transmission or rear drive. Drain thoroughly, measure the correct amount and fill.

I do the same after a level plug lied to me on filling a rear drive on an 850T. Left me stranded in the white mountains of New Hampshire back in 1976.