Fork Rebuild Questions

[gmlaverda]

I have completely disassembled and cleaned the components of my 1969 350 Scrambler forks. New 35mm seals and rubber boots are on the way. I am having issues sourcing the 3 different size snap rings and the dust scraper rings however. And each leg was a little different internally as one side had a paper washer and a thin steel washer on the rod, the other side did not. The parts catalog is fairly useful but does not really describe the washer type or size well. Just trying to get them correct. How much fork oil and what weight for a 150 lb. rider? Thanks

[Ventodue]

1969 350 Scrambler forks. I am having issues sourcing the 3 different size snap rings ...

Hi,

1. With reference to the drawing below, can you please check that the 3 snap rings are the ones I've marked with red circles?



If so, working up from bottom left:

* Part # 3075 is a 30mm internal x (normally, but check the old ones) 1.5mm. Part# 1440 is a 14mm external (x, normally, 1mm). Neither should be difficult to find - they're standard hardware, the kind of thing that seal and bearing suppliers stock. If you can't source them locally, you may have to use the internet. Btw, you may find them being called 'circlips' or 'C-clips', because a 'snap ring' is (for some people at least) strictly speaking ...

* The last one, part # 565. It isn't dimensioned in the parts book, so just measure up the old one. However, unless one is broken or missing, there's no especial need to change them for new. They aren't doing much of a 'Job of Work' ...

...and the dust scraper rings.

The piece highlighted in blue? Remembering what mine were like, I suspect they may well be a special part. Unfortunately, they're not on even the Amici's list of spares. So you may have to stick with the old ones. But, if your bike is wearing gaiters, they're not doing much ...

..but does not really describe the washer type or size well

As shown in green? Aluminium (i.e it's a crush washer which might explain why someone tried using a piece of paper ...), 12.5x18x1.

How much fork oil and what weight for a 150 lb. rider?

The 1970 owner's manual I have specifies 180cc ATF. (ATF = Automatic transmission fluid). You can still use ATF, but if you want to use fork oil instead, then it may help to know that ATF is around 10 weight - so try a 10 weight fork oil.

HTH

Craig

[gmlaverda]

I actually found the smallest snapring locally after 3 attempts, but not the other 2. I may just try a bearing supplier as you suggest for the others. Mine are being replaced due to corrosion and breakage.
I did manage to cleanup the 2 dust scraper rings that I have and will reinstall.
The washer I was questioning was #545. I had one on one leg only along with a paper washer. The other leg had nothing. I am assuming that a steel washer is needed at this location under the snapring.
I also just realized that I am missing washer #540 on both sides.
Small details that I would like to get correct. Thank you for your help.

[Ventodue]

The washer I was questioning was #545. I had one on one leg only along with a paper washer. The other leg had nothing. I am assuming that a steel washer is needed at this location under the snapring.

Right, got you. Yeh - steel. I see the parts book describes it as a shim (rasamento pistoncino) for the little piston, part # 525. Knowing what it does, does that enable you work out its thickness?

I also just realized that I am missing washer #540 on both sides.

The parts book says those are supports (battuta contromolla) for the little (conical?) spring, part #515. So that may help establish its external diameter. As to thickness, well it seems to be a chunky thing, similar to the washer/support (#435) at the other end of the spring. MIght be a starting point?