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Old 03-22-2019, 07:45 AM   #21
Railcarmover
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Default Re: Rear Main Bearing Oil Behavior

The original poster cited oil at thousands of psi due to 'squeeze'. I used the graphic to point out that no pressure is created when gravity lubricating the main bearing.I appreciate the fact that all anyone wants is to limit oil leaks but bear in mind,ford used seepage from the rear main and shift detent rods to lubricate the front radius rod ball assembly.



This is a 1931 Ford showroom..look carefully under the front of the cars they have drip pans..

Limiting the flow to the rear main journal by restricting the annular tube feeding the bearing is some dangerous shirt tail engineering..
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Old 03-22-2019, 08:21 AM   #22
Keith
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Default Re: Rear Main Bearing Oil Behavior

Brent,


We saw a instant where the welch plug was removed from the rear main cap and not put back in during the reassembly. The rear main leaked profusely and took awhile to figure out what was happening. Replacing the missing welch plug solved the leak.


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Old 03-22-2019, 03:39 PM   #23
dareheart
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Default Re: Rear Main Bearing Oil Behavior

Do what ever you want it"s your car. Mine don"t leak!
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Old 03-23-2019, 07:11 AM   #24
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Default Re: Rear Main Bearing Oil Behavior

Brent and I are on the same page. As I stated numerous times , the first order of business is to return the clearances to the .0015" specification. This in it's self is enough to keep the oil where it belongs. As soon as the engine is started up the wear begins again. The small tube I mentioned is only intended to prevent the flow of oil, when the clearances begin to get out of tolerance again, from overwhelming the ability of the groove and tube in the rear main to evacuate it back to the oilpan. By inserting the tube and preventing the oil from being slung into the bell housing you can save a clutch and any other parts from being contaminated by the oil.
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Old 03-23-2019, 07:39 AM   #25
30 Closed Cab PU
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Default Re: Rear Main Bearing Oil Behavior

Quote:
Originally Posted by roy green coupe View Post
One very important factor is crankcase pressure from blow by past the rings , this is certainly more important than what is going on in the bell housing.

Arm Chair Mechanic here. I thought the Crankcases Oil Breather Tube prevented crankcase pressure caused by blowby?


That is why you get fumes/oil on the motor on the drivers side, pushing fumes/oil out the breather tube on motors with blowby.


If I am wrong, would appreciate learning why.
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