1987 fork conical valve installation - which way?

Hi. I have an 87 510 TE that uses the Husky conventional fork (not USD) designed by Marzocchi so I am told. It has a floating conical valve ring that slides on the damper rod inside a a housing in the bottom of the fork tube. The valve ring is a non return device to control oil flow during rebound I guess. Anyway I have had the fork lock solid on two occasions now - one during rebuild while testing it and the second while actually riding the bike! The conical valve gets forced backward into the valve housing, distorts and grabs onto the damper rod locking the fork solid.

Clearly this is not good. I have confirmed I installed it as shown in the manual and parts book with the small end of the conical valve ring facing upwards on the damper rod. Attached photos show this. This seems wrong to me as the cone should face down to give a good seal on the valve housing chamfered seat and also to prevent it distorting as if obviously does if pushed down onto the lip of the housing "big end" first.

Can anyone confirm which way this conical ring should be fitted to work properly and not lock up the forks?

Thanks

Taper downwards. As in your RH photo...

Also, there are some upgrade parts and extra holes in the later damper rods. There are 4 extra holes in the parts you picture to let the oil escape from behind the fork seal when the forks compress.
There is a pic on the 'News' section on my site..

Hope this helps!
Andy

Thanks Andy. Exactly what I was after! I saw your cut away photo. What dia are the extra four holes in the damper rod? Cheers Steve

6mm. You need to drill through the alloy spacer tube (inside it) too so the holes go somewhere!!!

Andy

Hi Andy, I know this is an older subject but I was reading it due to I am rebuilding a set of 87 XC conventional forks and was just wanting to confirm if that tapered dampening ring is installed with the taper facing down or up? The 87 manual says to install the taper facing up toward the triple tree. Is the manual wrong in this case? Thank you for the help,
Marty

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