ARP Stud Help

[metros]

Way back before I received my 818 I had a local speed shop install the Evo (m12x1.5) ARP extended wheel studs and new wheel bearings at all 4 corners. I'm now getting around to installing my wilwood brake kit on my 818 and having some issues with the wheel studs. I went to test fit the 2-piece rotors and found that they'll fit on 2 out of the 4 corners (1 front/1 rear) and won't fit on the other 2 corners.

I assumed that the wheel studs maybe didn't get seated 100% and bought a few open ended lug nuts from the local autozone and stacked 6 washers before using my impact gun to get some torque through the stud. 1 corner stayed the same (almost fitting the rotors but not quite) and 1 corner improved but is now at the almost fitting but not quite stage as well. I've gone back through all 5 studs and re-drove the lug nut down on the washers. At this point I'm not sure what to do. I don't want to keep chancing that I'll strip an ARP stud and have a lot of work to repair it. But I also can't get the rotors to fit on the 2 problem corners.

Tips? How much can the ARP studs take?

Appreciate the help.

[Jaime]

Can you take a picture of where you're having interference problems? The inside face of the Wilwood hat should sit directly on the hub surface - the studs shouldn't interfere there. The only thing I can think of is that the splines on your studs are too long and they protrude past the hub outer surface. If that's what's happening, seating them deeper will make it worse.

You may not have had a problem with the Subaru rotors if they had a recess or a deep chamfer around the stud holes. I don't have my donor rotors any longer, so I don't know for sure.

[metros]

The rotor will fit maybe 1/4" onto the arp studs. The rotor doesn't come close to seating down.

[Jaime]

That's quite strange. Is it because the studs are have too large a diameter to fit in the Wilwood holes, or because they seem to be mis-aligned?

[metros]

More misaligned, they fit on one front and one rear corner. The studs look perfectly flat on the back of the hub. No clue why the rotors aren't lining up.

[Bob_n_Cincy]

Sound to my like the studs didn't get pulled in straight or got bent by whatever was used to install them.
I've done 6 wheels with those studs and have no issues.
Use a square against the hub and stud to see if they are straight.
Bob

[metros]

Putting a flat edge on each stud and the digital level on top of that I found a few studs were off. 2 were perfectly level and 3 were off ranging from .3-.8 degrees off. That doesn't sound like a lot to me. It may be enough to prevent things from lining up though.

Took the two offending corners off the car and back to the shop they go.

[C.Plavan]

Hammer...... :)

[metros]

I thought of using a 2 foot pipe that I use as a breaker bar to straighten them slightly. Then thoughts of being on track and second guessing the integrity of the studs crept into my head.

Better safe than sorry for wheel studs.

[Jaime]

Here's how I would straighten them with a little fuss as possible:

1. Bang the studs out of the hubs with a hammer. Make sure to thread one of the spare lug nuts part way on so that the force is on the lug nut and the threads and not the tip of the stud. Don't try to remove them, just leave them dangling.
2. Slip the Wilwood hat over the studs.
3. Mount a wheel. A cheap steel wheel would be preferred.
4. Use the lug nuts to pull the studs into the hub.

At this point, I think the only methods that will work are this one or C. Plavan's. The studs will try to follow the spline impressions they have already made in the hub, so simply removing and reinstalling will probably not make any difference.

[Jaime]

I thought of using a 2 foot pipe that I use as a breaker bar to straighten them slightly. Then thoughts of being on track and second guessing the integrity of the studs crept into my head.

Better safe than sorry for wheel studs.
A bar won't really help because it won't fit tight enough and will just be concentrating force on the end of the stud. The only "truly safe" way would be to spin a 12x1.5 threaded sleeve over the stud, almost all the way down and hit that.

Threading a lug nut on to the end of the nut is flush with the tip of the stud and hammering the lug nut would at least protect the threads.

[D Clary]

Lilse tools (I think that how it is spelled) makes stud installer, It has a tapered seat and bearing and you can draw the stud right in with a lug nut