I just installed a new clutch in my wife's 1986 745T. The engine has had a persistent oil drip at the rear of the engine. The Volvo rear main seal was fine, The soft plug, at the end of the intermediate shaft, at the back of the engine was not. I repaired the leaking soft plug with JB Weld.

Hi John,

I bet you were elated to find the rear main seal was not the leaker. My compliments on your (always) excellent imagery.
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Art Benstein near Baltimore

When you've seen one shopping center you've seen a mall.

I would be fine with that repair. It's not like you couldn't remove it if you had to for some reason. With a good surface precleaning epoxy is a good call for that application.

The other consideration is that the JB Weld was quick (probably on your shelf?) and you could make the repair and move on with the job at hand. I like it.

Randy

John,

I consider you to be a top notch mechanic, but are you sure you want to fix it this way? (Seriously, I looked at my watch to see if it was April 1.)

JB Weld is good stuff. Some brickboarders have successfully used it to stop 960 blocks from leaking coolant.

How would you have fixed it? A new soft plug might leak also.
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john

I don't know - it just always seemed to me that stopping a fluid leak at the outer surface is not a real reliable fix. If there is reasonably good access to the plug, then yes, I think I would personally feel better about replacing it. The very few freeze plugs I've actually had to replace in my life, I had pretty good luck driving one side inward and they tend to cant in the hole and the opposing side comes out, giving you somthing to grab on to.

Hopefully whoever installed it didn't gouge the heck out of the block somehow. Given the little-to-no pressure behind that plug, there must be something obviously wrong with one of the surfaces, or it's not a tight enough fit.

What I find notable about this is that this is apparently a 21 year-old clutch!

Unless this leak sprang since the last change, otherwise one assumes it would have been fixed then...

That looks like liquid gasket painted in there first, then JB to protect it?

Shifted

The engine was overhauled about ten years ago. Overbore, hot tank, etc. The machine shop installed the soft plugs and the visible liquid gasket.

I cleaned all of the old liquid gasket off and sanded everything clean with emery cloth before cleaning with lacquer thinner, followed by the JB Weld.

The clutch was new at engine overhaul.

Volvo rear main seals have a much tighter grip than aftermarket rear main seals. I use only Volvo rear main seals.
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john

p/n 463905-0 ?

I thought about buying a new soft plug (part number 463905), and installing it. However, if the soft plug installed ten years ago leaked, what would stop a new soft plug from leaking? Also, I don't know how much clearance is between the soft plug and the end of the intermediate shaft. You'd have to drill a hole in the soft plug and pull it out. Limited clearance between the soft plug and the intermediate shaft could make that a tough job.
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john

I am with you John,would not pull that plug out of a good engine in my car.Why invite trouble?JBweld and on your way.It will not likely leak in our lifetime.Bill

The gist of your message is the assumption JB Weld is a miracle epoxy that should join the ranks of other miracles occupied by Blaster, duct tape and WD-40. That John Sargent would trust it to a test risking a second tranny drop, gives it more legitimacy in my estimation, however I'd put more faith in the work John put in to clean the wound and create some tooth for it to adhere and stay put through temp changes. Guess I'll pick up some of that stuff next time I'm out shopping. Great post and we're all aware of the options John had.

Problem I see is your excellent photography makes it look as though this is laying on your workbench in a warm room, so it invites all us armchair critics to second guess you. Only comment I have about replacing the plug, you would come up with yourself anyway, but for others that might - don't use a drill on this one, rather if a hole is necessary to start a slide hammer screw, a sharp punch would be favored. The longevity of the crank seal is not only due to its manufacture, but care in installation and oil habits. Interesting to me was seeing the bosses that eventually were used to mount the flywheel index sensor. I always wondered when they appeared and if they did much earlier than the EZ-K system, what their historical purpose was.

The original engine (B23FT) in my son's 1984 760T had the two holes drilled and tapped for the RPM sensor. Volvo must have built all of the B23/B230 blocks for any fuel system they sold.
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john