Mk Gearbox oil

[Neil Warner]

What gearbox oil is recomended for the Mark 5 gearbox? is it the same for the Fly?

Neil

[Doug]

Neil,

I thought I read in the handbook straight 50W. That is what I use in my Mark 3 Sports. When warm I think it could tolerate a thicker oil as it noticably shifts better when cold and the oil offers some braking effect on the spinning gears.

-Doug

[eddie]

Neil,
       According to the handbooks, the Mark series uses 50 grade oil in the gearbox whereas the reccommendation for the Dragonfly is 140 grade. I am of the opinion that some of the changes of spec for the Dragonfly were an attempt to obtain a quieter engine and gearbox, rather than to improve performance. The gearbox oil is one example - another is the smaller tappet clearances, where you would have expected an increase in clearance with the change to alloy pushrods - maybe this is the cause of Dragonfly heads cracking! I have always run my Dragonfly with 6 thou clearance on inlet and exhaust, and 40 grade oil in the gearbox.
        Regards,
                      Eddie.

[Dawn]

Just to come in on this one, I too use SAE 50 in the gearbox, but my engine prefers SAE 40.

Hope between us we have answered your query,

Regards,

Dawn