Where to get extended leaf spring center pin? (1 Viewer)

[White Stripe]

I use grade 8 hex bolts from the hardware store. Whatever size fits I use.

 

[GRM]

GRM, if your grinding on a hardened hex head cap screw/bolt like a grade 8, the heat from your grinding has weakened the bolt.

vfer, I'm pretty sure a spring pin is essentially a grade 5 bolt, and fine thread, so the nut and bolt has more metal contact. I always carry spare bolts because breaking a spring pin bolt is not that uncommon.

I'm with pbgbottle, I use socket head cap screws(allen head). They are usually made from alloy steel and stronger than a grade 8 bolts and the head is pretty close to the same dimension as a spring pin bolt. We wheel pretty hard and I used to break spring pins quite often. When there's an issue with something breaking often, I try to find a solution. I haven't broken a spring pin since going to SHCS. The problem I have with bolting the shim to the spring is, that when you tighten the bolt down on the shim and spring the shank of the bolt will distort/bend because of the angle of the shim. This distortion weakens the bolt regardless of what bolt you use. I no longer attach steel spring shims to the spring. My spring pin bolts only hold the leaves together and locate the axle.

While I’m sure I have affected the heat treat of the bolt when rounding off the head (which, is only taking down the edge, not fully rounding the bolt), I highly doubt it affects the shaft of the bolt. Plus, a center pin is around a grade 3 bolt, so this is still stronger, even if I go to town grinding the head round.

I should also mention, I always run the centerpin ‘upside down’ with the bolt head going through the main leaf and the nut on the bottom of the pack. Every time I’ve broken a center pin its from the main leaf moving against the 2nd leaf. With the bolt shank at the main leaf it reduces that movement, and put the strongest part of the bolt where it is most likely to break.


In the last 20 years I have broken lots of center pins (a few cap screws too) but have yet to break a grade 8 bolt that replaced it. And the trucks that get abused the hardest are the ones with a fine thread grade 8 bolt & top lock nut instead of a proper center pin. It works well for me.

 

[pb4ugo]

I think the orientation of the bolt/pin head has more to do with whether the spring is for soa or sua. All sua springs I've seen the bolt head is on top the main spring and nut on the bottom of the pack.