transmission vent

[DJK]

In order to eliminate possible sources of leaks, I was thinking why not put a vent in the top of the trans. by removing the small plug near the speedo pinion and installing some 3/8" steel line as a vent. I noticed there is a hole in the front for one of the shift shafts that is not covered by the gasket. Any thoughts on this?

[dpollo]

there should be a gasket between the trans and the bell housing.  The trans vents along the input shaft and bearing retainer.

[DJK]

The gasket doe not cover the hole for the upper shift shaft. Someone mentioned it is an oil return, it is wide open to the bell housing area as far as I know, haven't checked where trans mates to bell housing yet. That is on today's to-do list.

PS I forgot there is no seal on the input, so it can vent thru there.

Edited May 1, 2020 by DJK
change

[Sam Buchanan]

2 hours ago, DJK said:

The gasket doe not cover the hole for the upper shift shaft. Someone mentioned it is an oil return, it is wide open to the bell housing area as far as I know, haven't checked where trans mates to bell housing yet. That is on today's to-do list.

PS I forgot there is no seal on the input, so it can vent thru there.

 

There is a bit of confusion here. The hole referred to as an oil return is located inside the bearing retainer. It returns oil back into the transmission that makes it way out of the bearing retainer . The hole you are referring to is for one of the shift rails and the gasket between the trans and bell housing should seal that hole. I'm not sure why there is a hole in the gasket at that location, maybe it is so the gasket will fit multiple applications.

Edited May 1, 2020 by Sam Buchanan

[dpollo]

if the upper shift rail hole is not covered, or surrounded, by a gasket, oil will leak from this area.

[DJK]

7 hours ago, Sam Buchanan said:

 

There is a bit of confusion here. The hole referred to as an oil return is located inside the bearing retainer. It returns oil back into the transmission that makes it way out of the bearing retainer . The hole you are referring to is for one of the shift rails and the gasket between the trans and bell housing should seal that hole. I'm not sure why there is a hole in the gasket at that location, maybe it is so the gasket will fit multiple applications.

Sam, that makes more sense about the oil return in the input cover. The gasket between the trans and bell housing has a hole at the upper shift rail location, so technically it should seal OK to the bell housing. When operating the Shift mechanism w/ the trans on my bench, I can make that shift rail protrude out of the trans., but that should not happen normally w/ properly adjusted control rods. 

Thanks for the clarification on the oil return, I am used to trans. with seals in the input housing!!!!

Edited May 1, 2020 by DJK
spelling

[DJK]

6 hours ago, dpollo said:

if the upper shift rail hole is not covered, or surrounded, by a gasket, oil will leak from this area.

The gasket has a hole, but it goes up against the bell housing. I just thought it strange that the gasket wasn't solid at this location. Shifting the trans by hand on my bench, I can make the shift rail protrude from the front of the trans., this should not happen with properly adjusted shift control rods.

Thanks for the response.

[dpollo]

when I have made this gasket I have not bothered with that hole.  The factory gasket has a slot running south from the bearing retainer, I always cut that one since it maybe allows any stray oil to escape.

[DJK]

22 minutes ago, dpollo said:

when I have made this gasket I have not bothered with that hole.  The factory gasket has a slot running south from the bearing retainer, I always cut that one since it maybe allows any stray oil to escape.

Yes, there is a slot in the bottom of the gasket.