Help - '78 Fork Rebuild

[0m3nc0w]

I went to change the fork oil in a recently purchased '78 R100/7 and when I went to drain it all that came out was a black ooze with grit in it, so I had to completely disassemble.

When I finally got both legs off the bike and opened things up it was apparent they hadn't been serviced since it was purchased new... the bushings were completely GONE, they had been pulverized into a fine grit and emulsified in the fork oil to create an interesting substance that had caked onto the dampening rod and all the internal parts like shotcrete. Soaking in turpentine for 2 days did nothing. I finally had to take them and have them commercially blasted with a high pressure steam gun to get all the crap out.

I'm now trying to reassemble them and the Clymers manual isn't as detail oriented as I might like. Several questions I have:

1. Do I have this small bushing in the right place?



2. Which is the proper orientation for the large bushing?
and
3. Do I have all the parts lined up in the correct order?



4. What the heck are these 4 extra rings for that came with my rebuild kit? When I disassembled mine these were definately not inside the fork tubes, the shocks or the dampening rod assembly.



5. The two washers on the right (above) were sitting on top of the fork springs, however they don't show up in the Clymers manual... Toss em?

6. Is the gasket (#40 listed below on the Clymer page) referring to the copper piece on the bottom of the dampening rod assembly or is this another pulverized part that I'll need to order.

[Bamboo812]

1; not sure. 2; curved end down. 3; see #1 4; large rings under top cap? middle ones replace copper washers if they are alloy. 5; toss them. 6; replace it with aluminum crush washers shown above (see if it fits)

[sprints@pldi.net]

I recently did mine - the large white plastic goes radius down, the small white plastic pushes in the bottom of the fork tube just inside the threads.
See Brook Reams fork rebuild images online -

http://brook.reams.me/bmw-motorcyle-reb ... k-rebuild/

[Seth]

I didn't think there should be anything where the copper washer is on the bottom of the dampener rod (part 29 in the drawing). Are you sure the small crush washer isn't part 42 that goes outside bottom cap of the fork leg from the bottom, sealing the nut that holds the dampener rod?
And I agree that the crush washers on the left are they for the top caps. I thought the bottom cap rings were more rounded rings, almost like metal o-rings.
Maybe someone put the large washers in the forks to very slightly increase spring preload.

[sprints@pldi.net]

Every book shows it differently and some with repeated upgrade parts in line with the originals - very confusing. Your small washer is actually #40 called a 'gasket', it replaced the copper washer and is the only true crush seal. It goes on the bottom of #29 and pinches between it and the bottom cap - it is the only oil seal and a little tricky to keep in place when assembling; the #42 is actually a wave washer to secure the nut. The bottom cap should have a more rounded copper ring. It is also tightened enough to crush and seal the oil.