Is rear main seal worth doing preventatively?

[zdj355]

I am doing some work on the bike to get it running since PO parked it in 2013. It would be pretty simple to replace the rear main seal now since I am replacing the clutch anyway and everything is off, but the cost of parts ads up quick. No indication of a leak. Does it make sense to do the rear main seal as well or just oring? Are they a known vulnerability?

[K1300S]

You answered your own question.  You are in there and it is cheap.
Yes.

[The Mighty Gryphon]

Welcome, I would definitely replace the o-ring.  Get a Viton one, they are only a couple bucks at your local bearing distributor.

The rear seal would be nice, but if money is tight and it isn't leaking you can probably let it go for now.  Of the five Motobricks I've owned, I've only replaced one rear seal, and that was on a bike with 120,000 miles.

Also, you can save a few bucks by reusing the clutch basket hardware.  MaxBMW recommends replacing them, but only the big clutch nut needs to be replaced because of the danger of the threads galling from the high torque.  The other parts do not require replacement according to the factory shop manual.

[frankenduck]

I subscribe to the adage: "If it ain't broke, don't fix it."

I also do oil changes with:
50% Mobil 1 15W-50
50% Mobil 1 High Mileage 10W-40

The high mileage oil has additives to:
1 - Cleanse (starter sprag)
2 - Recondition seals (rear seal, clutch nut O-ring, water pump)

[zdj355]

Ok, I probably won't do the rear main seal. Mainly because I don't have the right tool to drive it and I've seen the stories of 1 seal turning into 3 from improper installation. Thanks for the replies.