Main Drive Gear Seal

[Scrap]

RE: 57 Four Speed Transmission. About to install the seal I received from my HD parts counter, not an HD part, James Gasket JGI-35230-39-DL. It has a secondary seal. I assume the main seal faces the spacer and the secondary seal faces the sprocket. Is that right? Also, he included the small seal that fits over the main shaft and butts up against the main drive gear. I only see that part on later transmissions. It doesn't appear to be made for my transmission, I guess it would fit in the bore of the MDG if it is made for it. Is there any reason to use it? It seems that it would affect the position of the clutch hub. I have also seen advice on the site regarding the use of the cork seal. Should I use it? I was not going to use any gasket sealer, should I?
Thanks,
Sam

[1950Panhead]

Here is a photo of the main seal, this is an original drive gear, later drive gears have a seal, there is also a seal in the nut for the clutch rod.
You can leave the cork ring out.
Jerry

[Scrap]

Here is a photo of the main seal, this is an original drive gear, later drive gears have a seal, there is also a seal in the nut for the clutch rod.
You can leave the cork ring out.
Jerry

Thanks, just curious, is that a James Gasket Seal? Why do you suppose mine included the cork seal with the main seal from James? I replaced the cork clutch nut seal with two later style seals.

[Cotten]

I'll vote for the cork, Folks.

Just like in the 'book'.

Otherwise, you are betting solely upon the modern rubberstuff on the outside of the modern seal housing.

....Cotten

[Hog54]

That modern rubber stuff seal has sealled mine for 24 years,never a drop.

[RUBONE]

I like the cork for function and the comfort of nostalgia...

[Scrap]

I like the cork for function and the comfort of nostalgia...

How about gasket cement?

[Panacea]

I bought one of Ray's "O"-ring spacers for next time I replace a seal, so far, no need..

[Cotten]

How about gasket cement?

Scrap!

Back before seals had a rubbery skin, the metal housings were swabbed with a goober or cement, mostly as a lube for installation.
The cork was intended to seal the backside, so it was suspenders and a belt as a sealer. Goobering a rubber-skinned housing would be additional redundancy, but it might be the best way to avoid tearing the skin as it is pressed in.
(Then you better have the cork in there.)

It should be obvious that the counterbore for the seal must be dressed of all burrs and puckers from the staking of previous installations.
And don't forget to set up the main drive gear endplay before you install the seal and spacer!

....Cotten

[Panacea]

Cotten, sorry for the dumb question but don't you have to remove the mainshaft to set the endplay on the drive gear? (with the right thickness hard washer). I agree it's a good idea to check the endplay, but if it's wrong you're seal job just turned into "might as well go thru the tranny":) Or am I missing something?...Mike

[Cotten]

Mike!

The maindrive gear assembly floats independent of the mainshaft, and can be measured with or with out the mainshaft installed.
One merely puts a dial indicator upon the torqued sprocket, and then pull it in and out.

Adjustment using a variety of the inner thrustwasher would require the shaft to be removed, of course.
But most often it requires takeing up of excessive play, which is easiest to adjust by machining the spacer.

MDGSPACD.jpg

A simple counterbore where the gear butts against it can be cut precisely, however it takes a carbide tool at least.

MDGSPRCT.jpg

....Cotten

[Scrap]

As long as the spacer is now in the lathe, would you machine if for an O ring? Or do you think this is overdoing things. On my bike, at least, the tranny would not be the only thing that leaves a spot on the ground.

[Panacea]

Cool! I never thought of machining the spacer. Thanks for the insight!...Mike

[1962FLH]

well it may not be proper but I used the lathe on high speed and a 4" hand held grinder and it worked great in my 4speed for any years. Oh and it was in a 1976 93" stroker shovelhead and it did pass my torture test daily.

John

[Cotten]

As long as the spacer is now in the lathe, would you machine if for an O ring? Or do you think this is overdoing things. On my bike, at least, the tranny would not be the only thing that leaves a spot on the ground.

Scrap!

I see no practical advantage.

....Cotten