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Overdrive Leak

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mylesw

Jedi Hopeful
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Hello

I have a leak between the overdrive and the adaptor plate on my car. The box was recently out of the car and split and looks like the seal between the new overdrive and the plate is not so good. As getting the box in and out of the car is such a pain (and the od on the back of the gearbox) I am wondering if it is possible to fix the leak in situ. I am thinking about removing the rear mountings, undoing the bolts on the od so it slips backward a few mms on the springs and then squirting some hylomar in the gap to create a seal. Has anyone done this and was it successful?

Thanks

Myles
 
Hey Myles,
Notice no one has weighed in on this question. I'm no expert but went through a lot of overdrive issues last year so feel your pain. There is a fellow on YouTube, believe from your part of the world, who has an excellent video on rebuilding a Healey overdrive. Search "rebuilding Austin Healey overdrive" and should take you right to his series. Recall his company name being mentioned in them so maybe you could give him a call and see what he thinks ? As to your idea of trying to break that seal between the OD and the trans, guess it is worth a try, if you can actually do that and move the OD unit away from the plate enough without messing anything up internally and get some sealant in there. Know far more about overdrives now than I ever wanted to know after last year, but someone else who has rebuilt them might tell you "do not try that". Or just consider it more "Healey rust proofing" !!!
Good luck,
Mike
 
mylesw said:
Hello

I have a leak between the overdrive and the adaptor plate on my car. The box was recently out of the car and split and looks like the seal between the new overdrive and the plate is not so good. As getting the box in and out of the car is such a pain (and the od on the back of the gearbox) I am wondering if it is possible to fix the leak in situ. I am thinking about removing the rear mountings, undoing the bolts on the od so it slips backward a few mms on the springs and then squirting some hylomar in the gap to create a seal. Has anyone done this and was it successful?

Thanks

Myles
Click to expand...

Hi Myles,

I too had a similar leak. I thought since the car had been in a pretty bad shunt in the left front, and the front cross member bent in the center, the leak was caused by the restraining bolt at the OD slightly bending the OD case rearwards. I repaired by chucking the OD housing in the lathe and removing about .004 of an inch to make the surface true.

Since you want to try a sealant, I would not recommend hylomar, since it is a non hardening sealant. Try 'the right stuff' or a silicone product that would cure in place. Also, you should probably drain the box, open the case as you describe, and let it drain for a long while, and then try to clean the surfaces. After getting the sealant in the area, don't tighten up the box initially, let the product cure after you tighten up all but maybe half a turn. Upon tightening on the cured sealant, it won't shrink in the future.

Just a few suggestions, but I haven't tried your repair, but can sympathize.
 
I had a similar same leak between the o/d and the transmission housing on a Customers BJ8. Fixed in less than an hour.

Clean the offending area well. Go for a quick drive, come back, lift the car up and stand n wait. If it's anything like the leak I found it will be very small and will take a while to start dripping. Get some epoxy putty, Advance sells it. Use it to cover the area. When dry paint it green. I didn't try and loosen or tighten any fasteners for fear of making it worse.

This car has had an oil change since then and show no sign of a leak from the o/d.
 
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