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Vexing gearbox oil leak

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Andy65

Jedi Hopeful
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65 BJ8 with overdrive. Have oil dripping off the X channel of the frame to the right of the gearbox stabilizer. It is a significant leak drip....drip....drip after a 30 min drive. Lost nearly 2 qts in probably a couple tanks of gas. Can't for the life of me tell where it is coming from.

Oil appears to be on top of frame. Of course it could be blowing there. Is there anything prone leaking in this area? The only things I can see above the area are the speedometer drive and the overdrive lever. They may have a drop but nothing obvious. The propeller shaft flange seems oil free so I'm thinking the transmission seal is okay. Overdrive to transmission seal doesn't show oil.

Tightened overdrive filter brass nut. I know these can leak. Drain plug looks dry. Bell housing looks dry. Of course the drip stops shortly after the car stops. I'll check the newspapers in a day hoping. Could the speedo gearbox or overdrive lever leak that much? Is there any kind of pressure relief thing.

For this much oil to come out it has to be under pressure or leaking from a low point in the gearbox.
 
For a leak tha stops when the car is parked and that causes that much oil to be lost, I'd take another look at the output seal at the back of the gearbox. The adapter that rides in the seal (attached to the fwd universal joint)can sling oil so that you can't tell where it is coming from. You could rule out the tach drive by puttng a little plastic cup under it (use tape or wire it in place) and go for a drive and see if there is anything in the cup. Clean all the oil off and go for a short ride. You might find where it is coming from if you start with clean surfaces and drive only around the block. I should also warn you, I've been known to be completely wrong sometimes.
 
Anyone have an output shaft seal go? I would think if it leaked, there would be oil all over the flange and universal joint plus above where ever the rotating shaft slings it. Its dry up there I tell you!! It's dry! Hee, hee, haa lock me up. I've been on my back with a mirror too long.
 
Did you look around the speedometer drive, or the right-anglr drive? That's a well known problem area.
 
My 100 has leaked profusely from the OD control shaft, though the oil shows up well beneath this point when it falls off the OD. The control shaft is usually under the oil level in that unit, so it tends to leak whether parked or running. So it makes quite a mess and consumes plenty of oil.

There is an o-ring seal that when properly installed cures this problem. You need to drive out the pin and remove the actuating lever to replace this seal. I think it can be done with the tranny cover off but with the OD and transmission in place -- though I have not tried to do this job on a BJ8.

Good luck and good leaking!

Bill S
NM
 
Andy,

Have you checked the overdrive to gearbox joint? Mine had a leak that sounded just like yours for a very long time before I checked the bolts on this joint - embarrasing really, but after tightening up the bolts, only a few drops have been lost whereas before it was a lot.
I had been through every other possible leak before I checked this simple joint!!
Good luck
 
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