Trans cover oil leak-Should I plug this hole?

Idaho Stanger · 04-14-2012, 11:55 AM

Hi,

I've been chasing a oil leak at bottom of 3 speed in Genny (64.5 coupe w/200). I'm 90% certain oil is working its way out of this small hole on top of cover, moving backwards and finding its way to bottom of trans. My question is why? I checked oil level in trans and it was just below bottom of top most of two plugs on side of trans. With inches between this level and cover of trans, how would the oil be finding its way out. (Does it heat up alot inside trans?). Anyway, placing a piece of duct tape over hole seem to resolve issue. Should this small hole (is it a vent?) be covered? Would an incorrectly installed cover gasket be to blame? As allways, any help would be appreicated. Photo attached below.

PrecisionTrans · 04-14-2012, 10:38 PM

The hole in the cover is indeed a vent and should not be plugged. Take off the cover and check to see that the vent hole in the gasket is towards the rear of the trans. If the hole is towards the front, oil can pile up at the front of the trans during stops, and then find it's way out the cover hole.

Idaho Stanger · 04-14-2012, 11:10 PM

Aaahh! Thanks for the info PrecisionTrans, I'll pull cover off and check gasket. Am I mistaken or is it doable to do this with trans still in car? Car is up on jack stands and I think I should be able to remove cover and check. would I use a gasket sealer upon reinstallation?

Again thanks for your reply.

22GT · 04-14-2012, 11:42 PM

The 2.77 is so small there's a reasonable chance you can do it still on the car.

Idaho Stanger · 04-15-2012, 10:15 AM

I'm going to try to do this on the car. Just checked shop manual and last instruction in section relating to reassembly of the 2.77 trans clearly states to make sure gasket vent is to rear and that cover vent is to front. Great things these shop manuals. I should use them as a resource more often! They seem packed with useful information. LOL

Idaho Stanger · 04-15-2012, 11:00 AM

Done! Just removed cover and gasket. Gasket has two holes, about 3/8" in diameter. these holes were at the front end of the trans. cover. flipped gasket around 180 so they were at back end and re-covered. Hopefully that will be the end of this issue! FYI there was a bit of oil lodged between the cover and gasket, could see how it could migrate out the vent hole. Again thanks to all those whose input made this repair possible!