Big gearbox leak...

[ejenner]

I noticed gearbox oil leaking quite fast from the small cover on the front of the primary drive case. (where the input shaft lives)

Is it simply a case of replacing the seal on the cover? I broke one of the blades off the plastic propeller from the end of the input-shaft when I was changing the gearbox. Does anyone think the plastic propeller needs 4 blades to stop the oil from comming out the front of the box? Should I replace that as well?

[A. Nijhof]

Had the same problem. The O-seal will harden by time. As long as it is in place it will not leak. Once you remove the cover and install it again the seal will not be in the exact same position and starts leaking. IMHO the only remedy will be a new seal. Clean the surface of the cover and the primairy gear housing before installation. Replace the propellor as well if it's broken. It is out of balance now and probably breakdown futher, altough the mass is not that big. But when it thears down you got debrie in your gearbox oil, do not know what that will cause.

[ejenner]

Tis only plastic. would break-up pretty quick if it got into the gears! I'll probably get a new seal for the cover. I was pretty sure I'd do that but the explanation helps me understand why I need to replace it. Cheers.