sierra uprights. pinch bolt on the machined ring supplied by bgh geartech. seems alot of play, torqued to 70 nm, and still the ring can move. should i just bung a washer in?



also might it worth a longer bolt and nyloc for iva friendliness?

Has it run of thread on the bolt, Pull the bolt out and check the thread length, as a good bit more than 50% of the effective length of the bolt has to be threaded for clamp to work.

The neck of the hub is meant to clamp around the stub on the bottom of the damper. The blade is only there to clamped between the two faces so that it should prevent the damper coming out of the hub during unexpected extreme loads. So the moral is, keep tightening until there is NO play. Intially you will be tightening to pull the split circle together to clamp against the bottom of the damper.

Also make sure that (if using a shouldered bolt) the threads run up the bolt to the shoulder and the length of the shoulder is NOT longer than the depth of the blind hole, otherwise you could just be getting to the bottom of the threads and not pulling the clamp together.

As said I would be tempted to use a longer bolt and a lock nut for secrity after tightening.

B T i think this answers your question



JGG

i thought that was the case, just worried about snapping the bolt, i think the max for an m12 8.8 is about 90nm, and i wasn't far off that with loads of slack to go... will pulling the split circle together not increase the torque untill its completely clamped and is this where i'm going wrong?

Might be a stuped question

BUT

Are you fitting the bolt from the correct side?
The upright hole is threaded on one half and just a hole on the other side and the bolt fits from the hole through to the threaded side.

I know its a basic question, but always check the basics before going any further.

hmmmm good question...

Hi mrwibble,

The haynes manual gives a torque setting of 57 to 68 lbf ft for the hub carrier to strut pinch bolt.

Len.

thank you avogolen. I was being very stupid in not realising only one side was threaded, which of course it would have to be, or else you'd destroy the thread...

thanks for help

its good to check the basics before going any further