RE: Allison MD3060 oil leak
mooschi - 1/11/2009 8:09 PM
1997 American dream w/Allison MD3060. I have a transmission oil leak that is coming from what appears to be a pluged orifice that could be used for the dipstick if it were to be mounted on the opposite side of the transmission. The plug has a rubber seal with a metal plate above it and a 1/2 inch not protruding from the top. The oil leaks from this plug primarily when the vehicle is parked and shut off.
Can anyone tell me how to stop the leak? Any ideas would be appreciated.
From the factory, the 3060 had the option of having the dipstick on either side of the transmission. The unused hole has a plug installed in it. The factory plug is a push in plug and I don't think Allison ever used a plug that had a nut on it(could be wrong about that but I know the new ones are a push in plug). I wonder if someone removed the factory push-in plug and replaced it with a welch type plug.
My suggestion is, remove the plug that is in the transmission case now, probably by loosening the nut you see. Careful this plug does not fall into the trans. When the plug is removed you should just see a smooth aluminum bore. The factory push-in plug has an o-ring on it that seals the hole.
Get an inspection mirror and a light and see if the hole in the case is damaged. If it's not, get the factory plug from an Allison dealer or distributor and replace it. You can locate your nearest Allison authorized service and parts facility by using the service locator at
www.allisontransmission.com.
If you want to try a quick and easy fix, if the welch plug that's in there is the right size, maybe you can just carefully tighten the nut.
It leaks only when shut off because when the engine is shut off, half the oil in the torque converter drains into the sump.
Just a free opinion. I hope this helps.