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Steve, the machined spacers look very nice. I am currently waiting on the arrival of some cusco pillowball nuts from RHD japan to confirm fitment. If these end up not working, I will likely end up doing what you did but with a larger inner diameter to accommodate.
I should probably measure this again next time I'm in the garage, but my calipers were telling me the threaded section of the 8100 shaft was 12.78 iirc? thread pitch is definitely 1.25.
I'm actually getting shims done for my Penskes so I can just use a jam nut setup rather than the CUSCO nut spacer. It never threaded on smoothly enough with fingers or wrench not to just rotate the shaft, and there's no flat spot (on the JRZs at least) to hold the shaft, so I had to blow them on with an impact gun, which isn't ideal. I ran a tap and die on the shaft and not multiple times and it didn't make a difference.
I'm actually getting shims done for my Penskes so I can just use a jam nut setup rather than the CUSCO nut spacer. It never threaded on smoothly enough with fingers or wrench not to just rotate the shaft, and there's no flat spot (on the JRZs at least) to hold the shaft, so I had to blow them on with an impact gun, which isn't ideal. I ran a tap and die on the shaft and not multiple times and it didn't make a difference.
Peter, would you happen to recall if your shims will be threaded for the damper pin shaft (where they put the rebound adjuster), or unthreaded? Interesting bit of information you brought up regarding the JRZ damper shaft. Did not know they were like that!
Penske did a nice job with this - they added the flat part at the bottom of the threaded end so you can hold them while you tighten the nut. I still like the jam nut since I an a belt and suspenders kinda guy. Tighten the main nut then add the jam nut to ensure it doesn't back off.
The bushings Guy made are not threaded - I don't see a need for them to be. They are aluminum so won't bung up the threads on the shaft. I guess there might be a long-term possibility they would wear on the inside where they contact the threads but I am not worried about that. If you are worried, have them turned from steel. Any wear on the threads wouldn't matter since you won't be putting a nut where the bushings are. Actually, if this was a concern, Have an extra set or two made from aluminum. IMHO that isn't needed tho
And a doh! I didn't notice that they have the thread size listed on it!
Last edited by MilesBFree; Sep 7, 2023 at 09:11 AM.
Thinking more about it, i don't think you want the bushing to be threaded, as it is then basically a nut. it potentially becomes an adjustment where you don't want one. i.e., if it doesn't screw all the way down
What spring sizes are you guys using? We have perches for 60, 65, and 70mm springs, and 10mm as well as 12mm shaft spacers. Happy to help if you guys have JRZ, Penske, Moton, etc shocks and need top hats for them
Bumping this thread with an update. I finally got a spacer manufactured that will allow me to use my (formerly Steve's) 8100's with the cusco pillowball mount with the help of Turk82 (he did all the work, I just gave him dimensions and a shape)
I'll figure out the spacing on the bottom when I get the spring hats (might have to make those too! ) These are made out of 304 stainless (they didn't have any 316SS and 304 was sufficient for the application anyway)
The flared end will face down and will be secured with a jam nut.
) These are made out of 304 stainless (they didn't have any 316SS and 304 was sufficient for the application anyway)
