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Thread Like Summary
Allan G, ChiefRider, Nick H, NickL
Total Likes: 7
Original Post (Thread Starter)
#821522 08/28/2020 6:51 PM
by Nick H
Nick H
My '66 A65 is "finished" and I'm very happy with how it runs but it leaks oil at an intolerable level.
It is hard to tell where it is coming from but I suspected the oil pipe so I put in square O-rings from McMaster. Still leaks.
Has anyone tried a gasket here or a sealer with the O-rings?
[Linked Image from]
The oil drips from a low spot on the oil pipe itself or sometimes the frame but it is hard to tell the source.
I also suspect the joint between the case and the transmission inner cover.
[Linked Image from]
There is a gasket of course and I think I used Yamabond on one side and greased the other.
So before I take the inner cover off to check and all the kickstart and timing disassembly that goes with it,
is that a likely joint to leak? Is there much oil sitting behind that cover given the pump is clearing the sump effectively?
[Linked Image from]
I don't think it's coming from anywhere else like the sump cover or the pressure release. It is engine oil.

By the way if anyone wants a couple of the O-rings, PM me your address. I've got 100.
Liked Replies
#821573 Aug 29th a 01:04 AM
by NickL
Is the motor run-in, if it isn't crankcase pressure may be pushing past the points oil seal.
A smear of loctite 581 on the oil manifold won't do any harm rather than a gasket as that
would prevent the o rings from compressing.
If the timing cover is the culprit, they tend to be / have been overtightened in the past
which makes them an interesting shape..... Make sure all the case fixing points have no
'pulled' burrs by countersinking them slightly.
These motors are normally pretty good as far as oil leaks go, that 581 gear is very good too.

Just my 2c
2 members like this
#821807 Aug 30th a 05:06 PM
by DMadigan
Even without the dowel it should not have leaked if there was sealer around that hole.
To get a dowel out, put a close fitting rod in the dowel then use a collet to clamp on the dowel to pull it. If you do not have a collet you can carefully use a pair of pliers.
1 member likes this
#821718 Aug 29th a 11:09 PM
by DMadigan
The outside spindle diameter on the intermediate gear changed at some point from straight 0.685" to stepped 0.623" at the oil seal. Be sure you have the right seal.
On a late (rocker feed) oil union I measured the feed o-ring recess at 0.060" and the return at 0.050". The union is visibly not flat and still has the plating on it. Probably a victim of the make it tighter if it leaks syndrome.
I believe you have to lift the motor off the frame to take the bolt out.
1 member likes this
#821910 Aug 31st a 04:57 PM
by gavin eisler
gavin eisler
Remove the other dowel. Clean the gasket faces, apply engineers blue to one gasket face, or black sharpie , offer up the outer case give it a shimmy, you will probably find a dissapointing lack of uniform contact.

Use a 45 degree countersink to chamfer all the female threads, take a dead flat file and remove any other high spots, do the blue thing again, if there are divots in the faces from bodging types using screwdrivers , these can be filled with epoxy mixed with Al filings.
Once you have it as flat as you can get it, replace the dowels, stick the gasket to the outer cover with your goo of choice, grease the face which meets the main case. Insert all the fasteners and run up finger tight.

Now comes the important bit, lightly nip in the following sequence, start with the central screw, then screw at 12 oclock, screw at 6 oclock, working your way from middle part of case to outer diagonally.
The worst way to do it is start at 3 oclock then work round the perimeter ending with the centre screws , this can warp the case. in general if a case is longer in one dimension than the other its best to tighten from the middle outward ending at the long extremities , this also applies to the primary chaincase.
After all have had a light nip, leave it overnight , then repeat to final torque before oiling up.
1 member likes this
#822149 Sep 2nd a 09:31 PM
by gavin eisler
gavin eisler
Thanks for the credit, its just good workshop practice, glad it worked for you.
1 member likes this
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