VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc '32 rear main bearing leak with a twist

Could this be the source of my '32 194 rear main bearing (RMB) oil leak (see area highlighted in red circle)?







The oil drain in the RMB cap is clear and check ball had been removed in a previous repair attempt. The slinger and oil trough in the block and bearing cap are free of sludge and there is no evidence of the slinger scraping the sides of the trough.
I have had the RMB cap off a couple of times but I had not noticed what looks like material missing from the left and right side of the block that I believe mates up with the RMB cap. We have been discussing the RMB oil leak through various posting for a couple of years and I haven't come across this issue before.

Is this the source of my oil leak?
Can you suggest a repair option?

You have found your problem. I will send you the "fix" as I just sent it to another guy in Canada and is still in my files.

Chevgene,

Is this a common problem or is it just common for Canada?

What would have likely cause this symmetrical damage to the engine block or is it anyones guess?

As per the Chevrolet Mechanics' Repair Manual 1932-1936, I have checked:

The crankshaft end play is .002".

The clearance between the back side (tapered) of the oil slinger and the edge of the oil trough is .012"

However, I am not sure what to do about the missing cast iron material that form part of the oil trough just above the RMB cap as seen from the photos in this posting?

First the crankshaft should have between .004" and .006" end play.
There should be at least .002" clearence between the slinger and trough with the carnkshaft all the way forward.Then when forcing the crankshaft backwards there should be that amount of clearence on the other side of the slinger.
You give the clearence on the front side of the trough but the back side is important also. Move the crank back and measure it.
Has the slinger been rubbing on the trough, enlarging it?
Just want to be sure we are in the same train of thought.
I am not sure as to what I am seeing on the pictures.
From the center of the red circle in picture it looks as if sme material is missing from the block...is that correct? This may have been caused by too much end play at one time or???
Yes, this area should be built up ..is that your question?
How far up into the bloack area does this go?

Mike - between the above and your Emails I see what your problem is. Will have to give some thought as to the repair.

It might be easier if I was better at crafting the questions.

I would suggest mig or tig welding the block and then grinding to get the proper dimensions (match the other side). Since the repair is free to shrink without strain you should not get any cracking due to shrinkage. Mig (wire) welding with gas shield is relatively cool and should prove easiest to do successfully.

Chipper,

I will investigate the repair method you suggest. It would be a permanent fix.

I assume that welding would require pulling the engine from the car, removing the crankshaft, making the repair, re-assemble and re-installation of the engine?

I was hoping that it would be possible to fill the void without removing the engine by using some silicone product (as used in modern engines instead of gaskets) since the oil trough is not structural and is used to form a barrier only.

Has anyone experienced this kind of symmetrical damage to the engine block in this area before?

Never place silicone so it will come in contact with fuel. Fuel makes it swell up and look like a sack of frog eggs. When it enters the fuel system it is a sure breakdown that will require much effort to remove.

The only way I can see to fix this is to pull the engine out, remove the crank, welding more metal in and file to correct shape. It is possibly caused by bumping with the crank at some stage during removal or refitting.
Silicone will not work in this situation because parts are moving and as Ray said mixed with petrol causes BIG headaches.
Tony

I agree.......the only correct way to fix the problem is to remove the engine, disassemble the crankshaft and then do the welding. Anything else will be a temporary fix at best.

:( :o :cry:

Well, this grand old LP won't see the road again this year. :cry:

I'll begin preparations to remove the engine (I've never done that on my own before) :confused: and start searching previous postings in this site on "how to".

Some type of an epoxy wwould be better but still doubtful.

The epoxy option is interesting. I would need to find a way to form a mold while it was curing.

I have a urethane product called PolyAll 2000 used for wood, fiberglass and rust damage repairs. I'll have to find out if the urethane epoxy will survive the heat. It is resistant to most chemicals and gasoline.

Could JB Weld be used to build up the damaged area (assuming the damaged surface could be completely cleaned)?

A mold could possibly be formed by injecting a plug of Silicone gasket material into the cavity on the good side of the block. Some sort of release agent would need to be applied to the block and crank areas first to allow easier removal. It would also be helpful to imbed a handle/stiffener (curved to approximately match slinger diameter)into the plug/mold that would extended out of both ends of the plug/mold to aid removal of the plug/mold and then end-for-end it and insert it on damaged side.

Bottom line.......any type of "permanent" fix will probably require removal of the engine.

:( :o :cry:

After laying on my back under the car looking up at the problem again this morning, I have concluded that the Chevy guru's are right, the engine is coming out.

If I MIG it, TIG it or glue it, I have time to think about it.

The good thing about all this is the oil leak problem has been successfully diagnosed and a repair is possible.

Thanks for your patience.