inner primary main shaft seal

[flht1550]

I'm changing my inner primary seal in my 2002 flht that the transmission main shaft spacer runs in. i'm questioning which way is the correct way to install it. the way it was in when I removed it I'd say was face up but after getting it removed. . I can read on the seal that reads oil side, which was not the way it was installed. I say if the seal was installed with the words saying oil side facing in it I'd call that cup side out. I hope this is making sense and somebody can tell me the correct way to install this seal.

[fleetmechanic]

I recently replaced a 12052A seal on a 2010 that was leaking and the flat side saying "oil side" went in facing the chaincase.  Hasn't leaked yet.

[smoserx1]

The right way "looks" wrong.  Sounds like yours was installed wrong.  The oil side in this case is the primary/clutch direction and NOT facing the transmission. 

Shows it here:

https://www.youtube.com/watch?v=UaWHAPOwV08

[sandrooney]

I agree. The right way seems wrong. I learned this the hard way.

[flht1550]

Thanks guy's that's what I needed to know, I had a feeling is wasn't installed correctly. Always thought that the motor seal looked like it was installed back words  also.

[jjdalynh]

samesies (on a 2003).   The old seal 12052 looks flat when looking at.  The lip seal/spring garter is towards the oil side, same as the new one.  New one 12052A is 'cup side out' like you see.  Oil seal/garter spring is still towards inside ('oil side').

[smoserx1]

Just looks to me like if you put it in backwards there is a chance the lip might not make it onto the race, and I would be especially concerned about this using an S&S race with the tapered stop.  When I installed my S&S race it got real tight with about 0.2 inches to go to the MDG and I don't think the seal would have made it installed in reverse.  A massive primary leak would result if this is true.

[FSG]

so if your changing the seal ARE you changing the race as well and if so are you fitting the S&S race?

[JW113]

The oil side in this case is the primary/clutch direction and NOT facing the transmission. 

Um.... isn't there in the oil IN the primary/clutch? So "oil side" goes towards the primary, yes? Why would that look wrong?

-JW

[92flhtcu]

I was taught the rule of thumb is the spring side goes to the fluid you are trying to seal in(meaning the side you can see the spring from)

[mrmike]

I was taught the rule of thumb is the spring side goes to the fluid you are trying to seal in(meaning the side you can see the spring from)

Yup.

Mike

[JW113]

I'll drink to that. But... what do you do when there is a spring on BOTH sides? Ala fork seals.

-JW

[smoserx1]

Um.... isn't there in the oil IN the primary/clutch? So "oil side" goes towards the primary, yes? Why would that look wrong?

Because on many seals the lip and spring are on the cup side but not on this one, and that may be why the words 'oil side" are embossed on this particular seal.

[92flhtcu]

Rule of thumb for single spring type seals....

[mrmike]

I'll drink to that. But... what do you do when there is a spring on BOTH sides? Ala fork seals.

-JW

Well then either way your going to be right, lol

Mike