Roadster Upper Control Arm Nut Size and Thread Pitch?

[32J]

Hi - My front upper control arms were shipped without a nut and washer on one of the arms (see photo). What is size and thread for this nut and I'll see if I can get one at the local hardware store.

20211029_214423.jpg

Thanks,

32J

[Jeff Kleiner]

I don’t know offhand but you have 3 there—-take one to the hardware store and match it.

Jeff

[32J]

Yes, was going to do that for sure. My local Home Depot, though, has limited selection. I may have to order online. And I'm also mildly OCD... I can't have 1 thing not like the others! (Maybe it's a carry-over from watching Sesame Street too much as a kid? ).

[johnnybgoode]

I'm pretty sure those are "Stover" flange nuts that are a form of locknut. Mine were quite hard to tighten up and you just snug them up to the bushing so the arm will move freely and the locking feature (they are slightly oval) of the nuts stop them from backing out. Scott

[JohnK]

I believe those control arms are made by SPC Performance. Give them a call.

https://www.spcalignment.com/race

[Jim1855]

Just measured mine. Took longer to find the tools than to measure the shaft and nut.

9/16-18 7/8" hex X .5" thick will work but these may not be the "factory" issue.
Probably not a hardware store size/pitch. www.mcmaster.com will have them you just need to decide on what type.

A digital caliper with IN/MM units and thread pitch gauges again IN/MM are really handy tools. The caliper will get used a lot and the pitch gauges will minimize mistakes.

I'm not good for much but I can measure things.

Jim

[32J]

The 3 nuts that were supplied, they were pretty tough to tighten. I think they may be a type of 'deformed thread' locking nut. I found a nylon lock nut in my shop with the correct thread pitch, so I used it along with some blue threadlocker. Hope that's okay for now. Can always change it after go-kart shake down.

32J

[johnnybgoode]

A nylock and washer should work as well as the flange nut. FWIW the rear passenger side nut is the easiest to get to on a finished car if you are planning to swap it out later. I also regularly check/adjust those nuts whenever I grease the front suspension. Scott

[edwardb]

For a critical suspension part like that, I'd sure recommend getting the original parts. No excuse for them not being there. Your temporary parts are probably OK. But I'd get the right ones on there for the long term. As already mentioned, those are SPC Performance parts. If FF won't supply the missing parts, seems that SPC should. Best guess is they're the ones who messed up.

[JohnK]

Some threadlockers can damage some types of plastics so out of an abundance of caution I don't like the combination of thread locker + nyloc nut. There are "plastic-safe" thread lockers but those aren't that common. If you're worried enough to feel you need a nyloc nut plus thread locker, you're better off just getting the correct deformed thread nut.