flanged crank main seal

[N3377D]

I have an a65 with a flanged crank. The main seal leaks a little bit as do the pushrod tubes valvecovers, mag gaskets and rearcover.This engine is a 46' model that has 297 original hrs on it. 37 of them this year after sitting for 35 years and has never been apart . I have reasearched replacing the seal and have found nothing like what my engine has. Behind the flange in the bore where the seal should be is a machined aluminum piece that fits tight in the case with some type of seal behind it. It looks like a washer machined from about 1/4 inch aluminum that is split into 2 pieces to fit behind the flange. My question is has any one seen this before and can this aluminum piece be removed without splitting the cases?

[astjp2]

Re: flanged crank main seal

Sounds like the thrust bearing, get a manual out for the engine and take a look at the front bearing images. Hope that helps. Tim

[resojames]

Re: flanged crank main seal

It sounds like a trick we used to use on engines that had so much blow by that we had to put a flange on to keep it from blowing the seal out of the seal recess. The factory rubber seal it self has a rib running around it that fits in a groove that keeps it from popping out. However, you had to split the cases to install this seal so most aftermarket seals do not have this ridge and do not stay in nearly as well, thus the home made seal retainer.

[Ragwing nut]

Re: flanged crank main seal

How far back is this "washer"? 1/2"? If so you are looking at the thrust face and you have no seal installed. Should have a split rubber seal that is flush the the exterior cast surface for a flange crank. If it was taper crank, there was a metal seal that was original. Any pics?

[N3377D]

Re: flanged crank main seal

This mystery piece is not something someone has made and used as a patch, it was there from the begining I am almost positive. I don't have any pics yet but it is looking like no one has seen this before. I guess Im going to have to show yal what it looks like and so you don't think I am crazy.The engine runs great, just leaks a little and I had to take it off the plane to rework the exhaust so I am starting the dreaded process of getting in deeper and deeper !

[Len Petterson]

Re: flanged crank main seal

To the best of my knowledge a flanged crank has a split seal. It is made to be replaces without disasamable the engine. It would be impossable to but a solod circle over the cranktrough ot the forge flange anyway.
Len

[Mark Julicher]

Re: flanged crank main seal

I'm going to be in Ft Worth for about 10 days starting next Thursday the 5th. Would it be possible for me to come look at your mystery part?

[N3377D]

Re: flanged crank main seal

Well the mystery seal has been removed. I have pics but gotta get some help posting them. Turns out it is not a washer shaped piece, but an aluminium chanel shaped cage around the out side of the entire rubber seal.The seal didn't have a spring like the new ones it has a metal spring device bonded in the rubber to push on the lip of the seal. I think it may have just been a seal with a different design than the current ones. The pics will tell the story, anyway its out without splitting the case and a new all rubber seal should work fine.

[N3377D]

Re: flanged crank main seal

Here are the photos. Has anyone seen this before?

[Ragwing nut]

Re: flanged crank main seal

Looks like a tapershaft seal cut in half, but they were standard issue double sided garlock seals. I would install a correct FACTORY CONTINENTAL seal and be done. Do not use a Superior seal, they are too soft and have a tendency to weep.

[Forrest Barber]

Re: flanged crank main seal

yes someone modified another type, you need to use a genuine split seal for the flanged shaft. clean the shaft & case real well I then rough up the crank a wee bit with spiral groves that lead the oil back into the case when the shaft is turning. I use Goodyear plio bond , I am sure newer stuff is out there. Do you ahve a mechanic who has done this before??