1928/29 Model 72/75 rear main seal

[BlueDevil]

There has been a lot of good but conflicting information confirming both the inclusion of a rear rope type seal and just an oil slinger.

 

I put both my 72 and 75 engines together with those seals that were in my gasket kit and ran into a major problem.

 

It took 80 #/ft. of torque to turn the engine over, the starter was useless and there was definitely no way to hand crank it.

 

I am going to remove the seals and try it without.

 

All the bearing clearances are good. I loosened all but the front and rear main bearing caps with no effect, but when I loosened the rear everything turned smoothly.

 

I guess there is a reason for the nearly 1/2" hole in the bottom of the rear main cap.

 

I will put it back together and see how things go.

 

 

[BlueDevil]

Also, if they were using a rope seal, why would there be a slinger on the crank to begin with??

[stakeside]

Are these engines similar to the Dodge Bros engines?

[leomara]

You may want to bounce this question off of Restorer32 because they (Penn-Dutch Restoration Services)  just finished my Model 72 engine rebuild....

[viv w]

Yes that 1/2 inch hole is there to drain the oil back into the oil pan from the trough, make sure it is clear. Model A Fords work on the same principle. Where your pencil is pointing into the hole, are there any threads, as some motors have a drain tube screwed into the bottom of the rear cap.

 Also the babbit on that bearing looks a bit crazed and maybe breaking up. 

[BlueDevil]

That is assembly lube that has had a few turns. No threads. The babbit is like new

[Vintageben]

Hmm yeah having a look through the manual I cannot see any seal just the slinger and drain hole. I know my 65 doesn’t operate with a seal and works fine.

[stakeside]

If the oil reservoir behind the rear oil can not contain the oil flow it will overflow and drip out the bell housing. It may be  the rear bearing is in poor shape the wear will allow excessive oil flow to the reservoir.