gearbox Oil

[Mark]

Hi, I have a recently acquired 1989 Featherweight - quite a rare beast, being an SEF*. The gearbox should be 90 grade, but it appears to me that the seals are not what they were let's say. So can I get away with 140 grade?

[CatiGull]

Check out the FAQs Mark, that one is covered. If you dont mind a puddle of SAE 140 where you store your engine, the short answer is yes....although I would put it right...