rear main seal----what a beast

[John M]

Spent saturday stripping transmission ,clutch and flywheel to replace rear main seal and renew clutch on my 1986 R65 everything went smoothly other than pulling the rear main seal (what a beast ).  It wouldn't budge using a slide hammer.. the screws I installed in the metal lip just tore out.
I finally used a large slot screwdriver to punch the outer edge of the seal
in towards the centerline of the crank ,then spent an hour cleaning off black rubber from the outside edge of the seal which had bonded to the aluminum. All good in the end, I wouldn't have tackled this job without the support I get from this site  (Nmaf's clutch rebuild with pictures helped me be well prepared before I started )  Thanks to all of you,
Best regards John ---------  see you in Bloomsburg

[Bob_Roller]

Did you remove the cap that goes over the end of the crankshaft before trying to remove the seal ?

[John M]

The cap was removed with a puller purchased from Ed Korn at cyclewerks
 the outer edge of the seal seemed to have bonded to the aluminumof thecrankcase.

[Rob Valdez 79 R65]

I had the same problem with the input seal on the replacement gearbox I bought last Fall.
It is a smooth-side-case gearbox (old) and I wouldn't be surprised if it weren't the original seal.  It was VERY nasty!

There is the potential of hurting the outside sealing surface, using the method we used.
You probably had less chance of that, as the seal you worked on is much larger diameter than the one I was working.

[John M]

I was very careful in the placement of the screwdriver  I used to separate the seal from the aluminum driving the seal inward a little bit to force a separation  from the aluminum . The hardest part was getting the residual  black rubber off the aluminum once the body of the seal had been pulled out . this took about 1 hour of finger nail picking and scouring with small pieces off plastic scouring  pad infused with brake kleen spray,

[nhmaf]

A job well done - hopefully you'll never need to go into that area again on that bike!
But beware, owning airheads is like a creeping moss, first there is only one in the garage, a year or three later, there are two, and then..

[John M]

Having been successful with this job I am going to pull the heads for a rebuild and probably put new rings on my pistons ( I expect that the nikasil barrels will not need replacement ) . the bike has been burning  some oil in addition to what it was leaking through the rear main seal.
My trip last summer with some extended high speed cruising (135-140 kph for several hours ) seemed to be the beginning of the major leaking of the rear main seal.