General Tech OD Transmission Leak

I posted about this many months ago. TR4A Overdrive transmission gear oil leak--appears to be from the side plate where the solenoid sits. But it's very hard to be certain.

Geo was kind enough to offer his lift, but I've been so busy I haven't made it over there, not to mention I'm reluctant to drive the car with such a bad leak.

The car has been sitting since about last Christmas.

Well, today I started the process of getting the car ready to tear apart again so I can access the transmission. I first checked the catch pan I put under the car to catch the leaking gear oil. I'm serious--there's over a quart in the pan. I've literally lost half or more of the total fluid, and the car has been sitting idle. I've just never heard of such a thing. I asked once before, but to leak like that something pretty darn bad must be going on.

I'm not sure I'll know until I get the side plate off, but even then I just can't imagine that kind of a leak. Does anyone have an advance clue I can look out for?


thx

My guess would be one or more of the following: plate is warped, bolts holding the plate are loose, no plate gasket nor sealant, or gasket torn. It could also be a missing or worn "O" ring around the operating shaft that goes through the plate.
Bob

Use UV dye to figure it out. See my experience here...
https://spitfiremk3.wordpress.com/2...verdrive-filter-cover-for-a-triumph-spitfire/

If you take off the transmission cover, you have good access to the OD and that plate from inside the car. Might want to remove the driver's seat for a little more room.

If it is indeed the plate, the shaft seal is a likely culprit. I'd drain the rest of the oil, remove the plate, replace the seal, clean the surfaces, and replace it with a new gasket and sealer. That really should seal it well.

If it's not the plate, the lower edge of the OD-to-adapter plate seal is another likely leakage point. The plate is not strong and can easily warp. To reseal it, you'll have to remove the overdrive, which is a royal pain, so, before doing this, be SURE the leak isn't somewhere else. Then, again, clean the surfaces and install a new gasket and sealer.

Thanks everyone; I’m on it.

Just fyi, and FWIW: I pulled the transmission. I'll fix that side plate; that's where the leak is.

It took me twice as long to remove the transmission because I deliberately (and wrongly) left the rear cross member in place thinking I could pull the transmission out so long as I removed the bolts holding the transmission to that rear mount. No--the rear mount must be unbolted and extracted (unless the Incredible Hulk stops by the give you a hand and something magical happens). The reason is that the transmission is made with an underside hump that hits that cross member when the transmission is pulled back, even if unbolted from it. I simply must be removed. Following the manual is the only way to go. If ever a car is made that in the future will have such a step by step manual as does the Triumph, times will be good.