The Stovebolt Site Forums The Shop Area Driveline transmission oil leak.

I have a '37 chev with a 61 261 eng/37 tranny combo. I know there is an oil leak past the driveshaft seal and religiously check and refill thru the fill hole until it starts dripping out. This time after topping off I developed a sizeable oil leak thru the 1/4" dia hole located on the underside of the snout of the transmission bearing retainer. Never happened before. Anyone have any ideas as to why? Want to parade the car over the holidays but don't want to wreck anything.

1937 was the last year for a carbon throwout bearing. With that setup there was no snout on the front bearing retainer for the ball bearing throwout bearing.
In installing a 261, you or who ever did the install would have needed to replace the front bearing retainer with a 1938-47 4 speed front retainer, needed for the clutch design that would fit the 261.
There were two styles of that bearing retainer. 1938-46 and 1946-47 (early and late in 46)designed to work with an input shaft with "oil return grooves on shaft", that moved any oil back into the transmission.
If the wrong retainer is used there can be leakage from the front of the transmission.
A lot of people use a sealed front bearing (but remove the rear seal to allow oil to enter it) to stop oil from exiting the front of the transmission.
You would be safe to run the transmission a little low on oil to prevent oil from leaking out the front.