I have a good sized oil leak at my ball cap on a 1926 T. Is there a good way to fix it without taking off the oil pan? ( or at least slow it down) I tried the blue sealer but it did not seem to make a difference.
Sounds as though your ball cap has too much clearance to the transmission tail shaft which could explain the oil leak. A loose driven plate plug could also cause excess oil from the transmission to come out from the ball cap.
Another cause could be a worn "ball" at the end of the torque tube resulting in fore & aft movement but the u-joint area should be packed with grease so under most scenarios, the grease would be migrating out of the ball cap cavity not oil if there was excess wear.
A few things.
The clearance of the 4th main. Babbit bearing at the rear of the transmission. If too loose the oil will leak.
There is a plug inside the tail shaft of the transmission. If it is missing, oil will leak.
If you use two gaskets it will leak. There should be one gasket between the back of the transmission and the 4th main. The ball cap does not have a gasket. If it is too loose, a shim can be placed between the driveshaft ball and the ball cap.
You need to completely pack the universal joint with grease which will slow leaks, and don't overfill the engine with oil. It should be above the lower petcock but not above the upper one.
It will still leak oil, but not as much if all the above are in good condition.
Maybe too much oil…at least it shows that you have some oil. Up to, but not above, the top petcock is enough. A lot of folks that "rebuild" engines think the freeze plug like plug isn't important and don't put it in. You can check it by dropping the rear end and looking inside the u-joint hole.
A fix, that really isn't a fix, is to try to install some kind of plug or plugging material into the end of the transmission, though the u-joint socket (hole). There's not a lot of clearance at the end of the U-joint though so you can't stuff too much in there
I have the same problem on my '15. Just fill the the U-joint area completely with grease as others have suggested.
The way I do it is to remove the grease cup, and put a short length of tubing on my grease gun and run the tubing past the U-joint to the bottom of the cavity and pump it full. This will avoid an air pocket. Next put the grease cup back on and you should be good to go. Joe
I thought ball cap at first but reading Don's post again, maybe he is referring to the wish bone pan mount??