Effective rear main oil seal in a '57 283?

[Perry M.]

Re: Effective rear main oil seal in a '57 283?

Before I did my seal replacement I did a lot of research on the subject. I came to believe that there is only one replacement seal available and that being the Best 3711X. Others sell it as there own. When they were first introduced, the kit contained the wires to make the seal fit tighter in the grooves. The wires were latter dropped, not sure why unless they made a newer, thicker version. All I know is that the no wire version fixed my oil leak. Good luck and let us know the outcome.

[G B.]

There is no joy in Mudvillle

I just finished removing the rear maincap. The two-piece seal is installed correctly. The ends do project slightly above the cap and block mating surfaces. I can see the thin remains of gray silicone on the mating surfaces, too. In other words, I can find nothing wrong with this installation of the Best Kit. Also, the crankshaft surface has no wear grooves that I can see or feel.

I'll try the four-piece seal kit design next, but I have very little hope that it will work any better. You guys with no-leakers have "got you a 'tater" as some say in Alabama. And in Mike McCagh's case, multiple 'taters... a regular 'taterfest, as it were.

There's always Plan C: shop on-line for a drip diaper.

[Joseph L.]

Re: There is no joy in Mudvillle

I followed this procedure on my 1957 engine and have not had a rear seal issue. It has about 2000 miles now.

1. Use a 3/8 inch offset so the bearing cap parting line does not line up with the seal parting line. Push the end of the seal up into the engine block case 3/8 inch; this offset will be on the bearing cap as well.
2. Install the other seal half in the bearing cap. The 3/8 offset will be sticking out on the opposite side.
3. Apply sealant (like Permatex Ultra Copper) to the bearing cap to block interface. The sealant will be between the flywheel flange and the flange on the crank where the rear bearing ends. Keep the sealant off the seal split line; only on the cap mating surface next to the seal.
4. Install the rear main cap and torque to specs.

Joe

[Gary J.]

Re: There is no joy in Mudvillle

If you want to use some good sealant try this. I have had good luck using this. You can buy it at your local GM dealer.

[Jimmy G.]

Re: There is no joy in Mudvillle

On a lighter note remember this "If it does not leak -- It can't be a Chevrolet"

[Edward M.]

Re: Effective rear main oil seal in a '57 283?

Jerry touched on an interesting point, and I recall hearing something similar many years ago. Once an engine has been align bored, the specifications for things like clearances for rear main seal are changed / altered. I am not sure how to measure and adjust for that.

[G B.]

Conclusion

With the help of the machine shop owner, I installed the new 4-piece neoprene kit yesterday. I off-set the seal mating surfaces about 1/4". I used Ultra-Copper silicone as recommended in the instructions. I made triple-sure the seal lip was installed correctly, and let everything sit dry overnight to allow the silicone to set.

Unfortunately, it still leaks. Not as bad as before, though. I now have a 2" circle after a long drive, not a 4" circle. I'm going to live with it. I've had all this fun I can stand. Of course, I could pull the engine, take everything apart, and have the seal seats in the cap and block made perfectly round. Yeah... ri-i-i-ight. I'll just buy more oil.

My thanks to all those who offered encouragement and told me about their personal experiences. A special thanks to Mike McCagh who gifted his new kit and refused all payment. That was classy.

I now return to the Fortress of Solitude and back to work... on something I can fix.

Jerry

[Mike M.]

Re: Conclusion

sorry to hear the 283 still leaks. agree that an occasional qt of oil trumps pulling the engine. regards,mike

[Edward M.]

Re: Conclusion

Sorry to hear that you still have a leak.

I am really wondering if your previous comment about an engine that has been align bored may have some bearing on this situation.

It would be nice to figure this out once and for all.

Good luck Jerry.

Ed

PS: I agree, the Maryland Missile is a class act.

[Perry M.]

Re: Conclusion

I too am sorry your motor still leaks. I never would have thought that line boring could cause a seal failure. I need to research that further. It will only leak when running so clean it after its been sitting for awhile and then do not start it again, ever.

[Joe R.]

Re: Conclusion

You know what they say! If at first you don't succeed use larger hammer!

Happens with old Corvette owners all the time!

JR

[Bill S.]

Re: Conclusion

Sounds to me like either your align bore was not done correctly or the rear main seal journal is egg shaped.

[G B.]

Re: Conclusion Redux... wherein I am covered with shame.

Driving during the last two weeks convinced me that the oil leak had NOT been reduced by replacing the 2-piece Best rear seal with the 4-piece design. So I did what any other obsessive car nut would do: I took things apart again. I removed the driveshaft, shifter, transmission, starter, oil filter canister, bellhousing, clutch, and flywheel.

And there it was. The machine shop had not fully tightened the threaded plug in the rear of the right oil gallery passage. This plug is located above the rear seal, the the oil had run down and out as if the seal was leaking. You can see the oil sheen in the second photo. It's obvious in the third photo that one plug had not been tightened as much as the others.

I replaced all three plugs (using thread sealer paste) myself. I know this engine will eventually start spotting the floor with something, but I am absolutely thrilled that it isn't leaking anything now. Who knew it was possible? Well... actually several of you told me it was, I just didn't believe I could achieve your success.

.

[Dick W.]

Re: Conclusion Redux... wherein I am covered with shame.

Driving during the last two weeks convinced me that the oil leak had NOT been reduced by replacing the 2-piece Best rear seal with the 4-piece design. So I did what any other obsessive car nut would do: I took things apart again. I removed the driveshaft, shifter, transmission, starter, oil filter canister, bellhousing, clutch, and flywheel.

And there it was. The machine shop had not fully tightened the threaded plug in the rear of the right oil gallery passage. This plug is located above the rear seal, the the oil had run down and out as if the seal was leaking. You can see the oil sheen in the second photo. It's obvious in the third photo that one plug had not been tightened as much as the others.

I replaced all three plugs (using thread sealer paste) myself. I know this engine will eventually start spotting the floor with something, but I am absolutely thrilled that it isn't leaking anything now. Who knew it was possible? Well... actually several of you told me it was, I just didn't believe I could achieve your success.

.

With a Chevrolet engine, that is only a momentary situation. Don't put your drip pan away, you will need it shortly

[Mike M.]

Re: Conclusion Redux... wherein I am covered with shame.

jerry: great u found the source. several years ago, i installed the 265 engine in a 55 i was in the process of restoring. it too leaked profusely , from what appeared to be a rear main seal. eventually i pulled the old cast iron PG and discovered the same problem u encountered. the machine shop had the 3 plugs tight but they didn't add sealant to the treads, hence leakage. i gave the machine shop hell . henceforth,i've always pulled the 3 plugs, inspect, and then add sealant. the restored 55 now belongs to rick hendrick and i've not checked under the car to see if its pissin on his floor. regards, mike