Rear Main oil Leak Fix

[DaWizard]

WARNING! This is NOT a tried and true fix for the rear main oil leak, use this information at your own risk!!

Just to clarify this, I am not posting this for discussion, I am posting this because tomorrow morning the pan comes off my Tudor and I have a tool made to hopefully make this work, so I will be updating this with pictures and more info probably tomorrow evening.

This was found in the most recent issue of Speed magazine and I am letting you all know I plagiarized the article. I did not ask permission to copy it, nor did I ask to permission to post it. If this gets anyone in trouble, I apologize now.


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[DaWizard]

Removed the pan today and find that there is no clips to locate and hold the spring for the oil pump!

So, looks like I am going to need to fabricate some sort of clips to hold the spring on the bottom of the pump. Luckily the pump has 4 bolts holding the bottom together, so it shouldn't be too tough to make something.

Something else, the rear main didn't have a drain tube, nor was it loose in the bottom of the pan. Now, that could have had something to do with the constant rear main leak.

So, I have done the modification to the rear main and removed a .0005 shim to tighten up the bearing a wee bit. So, tomorrow morning I should put it all back together. RMOLF 1.jpgRMOLF2.jpg

[Mitch]

A very interesting read you posted in the tech sec. Well at least your Babbitt looks decent, do you plan to install a new tube? I hope so

[George Miller]

early 28's had the spring on the clean out on the bottom of the pan. Maybe you have a 28 pump.

[DaWizard]

Oh, the new tube is on and ready.

[DaWizard]

This is not the early pan as should be. The engine seems to be a transplant as even the number pad is too long for the car date.

[plyfor]

the vendors sell the spring holding clip that is attached by 2 of the 4 bolts, if that's what you're referencing.

[Tom Wesenberg]

the vendors sell the spring holding clip that is attached by 2 of the 4 bolts, if that's what you're referencing.

Yep, that's what I'd buy, and in fact often do, as the spring needs to be replaced if it has any rust or pits on it.
The spring was broken on the last engine I had the pan off.

[DaWizard]

Well, the spring is in good shape, got a new clip at Moss this morning along with a new valve cover gasket. Now that the gaskets are all in place, time to do the muscle work and get to the pan.

Henry sure could have saved some money on the cost of that oil pan, no structural support so no real need for that beefy of material... maybe he used a window cutout or something.

[Dennis]

What's this? Doesn't look good to me...

[Tom Wesenberg]

What's this? Doesn't look good to me...

Just a chip off the old block!

[Mitch]

Don't you like to reuse your old gaskets?

[Mitch]

JB weld

[Ed H]

What's this? Doesn't look good to me...

That would account for your leak

[DaWizard]

Well, I'm not sure it would account for all the leak, it is after all on the down side of the slinger, and since nothing rubs against that I don't feel it is anymore to blame for the leak than the gap between the cap and the slinger. So, I put it back together, and since I did modify it and tighten it up a bit, I think it will be fine.

[Mitch]

Do you have a pic of the other side of the cap after drilling the hole?

[DaWizard]

I'm not sure what you are asking for. I only drilled the hole through the babbit and enough of the cap to break into the oil return galley where the slinger puts the oil to return to the pan. I did not need to remove the galley plug to do this, so I don't have a picture of the hole through to the oil galley. I did drill the hole in a slight angle, maybe 5° tilt toward the oil pan to aid in flow, though the article didn't mention anything about it.

[Mitch]

OH ok i got it now, thanks for the clarification, i see that in the article

[Tom Wesenberg]

I'd be worried about taking oil away from the rear main thrust surface.

The crankshaft oil slinger rides in the rear groove, so I'd think oil would escape through the broken chip in the cast iron.
I'd want to plug it either with JB Weld or a good sealer that sets up.

[DaWizard]

Tom, I did not take ALL the oil away from the thrust surface, I only took away that which was being pushed out the bottom of the bearing. The top is still as it was, so I believe there is still some oil in the thrust area, just not on the bottom where is was leaking from. I hear no harmful noises coming from the crank.

[Dennis]

Did you check the end play of your crankshaft? How much was there?

You might want to check out the brass rear main seal Bert's has. I don't know how it is supposed to work but I was told it fixes end play and rear main leaks.

[DaWizard]

Just an update since it's been a week or longer and I am still driving it like I stole it.

I have NO (zero, zilch) oil leak from the rear main. I was hoping to get a pressure steam cleaner to clean the rest of the crud off the trans and flywheel housing, but alas, not yet. But there are NO drips in the pan from the cotter pin!!

The fix is in, it WORKS!!

[jfreddie]

As Tom W says, you will have thrust oiling problems...and it will appear gradually in the form of excess crank end play and oil leakage. I'd be sure and check what you have now so you can keep track as it wears...and wear it will.
I had a customer who did the same mod and it took about 5000 miles to start disintegrating the rear thrust. At that point it started leaking oil and had excessive end play.
We took off the rear main and ordered a new rebabbitted cap from Bill Barlow. The rear thrust had completely fractured and was only about 1/32" thick.
The rebabbitted cap was not a complete fix as the upper rear thrust was worn also. Now the new lower rear thrust was carrying all the load.
But with the lube restored and judicious light clutch pedal usage he was able to get another three years and 10,000 miles before the thrust finally wore again to start leaking oil.
Not trying to rain on the parade, but I believe your oil leakage was caused by lack of an oil tube.
I know you've put a lot of work into this mod...but if it were mine, I'd spend the $75 to get a rebabbitted rear main cap and replace yours before it does real damage.
Just my 2 cents...thanks.

[Mitch]

Excellent info!

[DaWizard]

Hey jfreddie, WELCOME to the VFF!!

Thanks for your input. I didn't know anyone else had done the modification. I did do a search of the interweb and didn't come up with anything before starting the procedure. Is that information posted somewhere? It would be nice to have something as a reference.

[Dennis]

Somewhere I read recently they can solder babbitt back on the thrust of a cap and block without having to completely do the entire block. You still need to cut the face of the thrust to fit the crank. That was what was wrong with mine, too much end play. Plus it had the small oil tube. I went a different route than babbitt plus 3/8" tube.

[jfreddie]

Thanks for the welcome...hoped I hadn't offended anyone.

When my aforementioned customer finally wore out his rebabbitted cap, and we pulled the engine all we had to do to restore the rear thrust was install a brass upper seal/thrust and order a new rebabbitted rear main cap. The end play and oil leakage was brought under control...without having to do a total rebabbitt.

Be interesting to hear more about soldering up the babbitt on the rear thrust block and cap. Would certainly depend on the amount of damage to the thrust and if pieces were missing. Also, what specific solder blend was used.

Could be very touchy with the temperature control.

Seems that if the block is already removed and disassembled to do the solder repair why not rebabbitt the whole rear main. That way the integrity of the rear thrust isn't an issue.

Just my thoughts...thanks.

[Mitch]

Welcome!!! jfreddie

[Dennis]

Thanks for the welcome...hoped I hadn't offended anyone.

When my aforementioned customer finally wore out his rebabbitted cap, and we pulled the engine all we had to do to restore the rear thrust was install a brass upper seal/thrust and order a new rebabbitted rear main cap. The end play and oil leakage was brought under control...without having to do a total rebabbitt.

Be interesting to hear more about soldering up the babbitt on the rear thrust block and cap. Would certainly depend on the amount of damage to the thrust and if pieces were missing. Also, what specific solder blend was used.

Could be very touchy with the temperature control.

Seems that if the block is already removed and disassembled to do the solder repair why not rebabbitt the whole rear main. That way the integrity of the rear thrust isn't an issue.

Just my thoughts...thanks.

That is what I thought, why not rebabbitt. I think it was a matter of pinching pennies.