Moser 60 and Wilwood 14"
 

Folks, ran into an issue during mock up and I'm looking for some suggestions on how to best remedy it. The rear wilwood rotors do not fully seat on the axle flange. Upon close examination - it appears the the shoulder of the axle studs are wider than the threads, so the rotor/hat hangs on them preventing them from fully seating. I see 3 options:

1) Have new/different axle studs pressed in. (PITA)
2) Put 1/4" spacers in. (Don't like this option at all)
3) Machine the stud holes on the hat.

I'd prefer #3. I am disappointed that you drop this much coin on these (guareenteed to fit) parts and they don't fit together...guess it goes with the territory.

It appears that the rotors are hub centric - they fit snuggly. Would it be an issue to throw the hats on my drill press and open up (or rather chamfer) the axle stud holes slightly?

Is it the camfer on the axle hub holding it off? Might have to slightly camfer the inner edge of the rotor hat.

If it is the stud bases I have never seen that, but if you cannot get the maching done there, send the hats to us and we will handle it.

Had the same problem with mine on my 67(moser rear), open up the holes in the hat. Measure the OD of the shoulder, increase the hole diameter .010" or so and re-chamfer the backside. :thumbsup:

Rich

This is a brand new problem. You both have the big boy 2 piece rotors, I wonder if it is exclusive to those 2 piece set ups? We did not have that problem on MotiV8tr which ran the same brakes you have, but I used a rear I had in inventory for 6 monts so maybe there is a recent change in materials

I will check with Moser on this and see if they are using different studs?

As I said Gale, I will be happy to do the machine work on the hats for you. Let me know when the hats are ready and we will send a shipping call tag on our nickel. We do not want it to cost you a penny. We can turn them around same day.

Merry Christmas

Update
 

Thanks Frank - I took more measurements and photos tonight so I was *absolutely* sure what was going on.

First the good:

I mentioned that the forgeline center caps were being pushed off the front wheels by the Wilwood dust caps. You graciously offered to machine them. I took them off just now and found a 1/8" tall casting tab on the back of the Forgeline center caps. I trimmed them off with a razor and it all fits perfect. What is nice about this, is that appears I have no fitment issues on the front of the car (final verdict when I install the fenders.) See the first 3 pictures. Hope this comes in handy for others...

Second, the bad:

It is definately the axle studs. Hard to see in the pics, but hopefully you will see the change in width at the base of the axle studs (it's about 1/16" wider than the threads). As suggested, opening the rotor hat holes by 1/16" would allow the hat to sit flush on the axle. However, in measuring it, the shoulder on the studs is taller than the face of the hat (shoulders are approximately 1/8" high and the hat thickness is less). This means that the studs won't fit into the Forgeline wheels completely - so the wheel will not seat properly. I tried just putting the wheel on without the hat and sure enough, it won't seat down the last 1/8". I think the only option is to replace the wheel studs on the axles with ones that are machined all the way down... maybe switch to the threaded in studs vs. press in? I don't think I can use a tap/die to chase threads all the way down - that is probably a bad idea anyway. Suggestions?

Those studs do look different. I will make the call Monday.

Frank, I had the same problem with mine when I installed them. All I did was took a sand paper boring toll and cleaned the hole on the rotors a little. Slips on and off fine now.

I'd just open up the rotors to fit the studs (or let Frank do it since he so graciously offered) and then countersink the backside of the wheel if necessary. I would think that with the rotors in place, the wheel shouldn't have any issues since it'll be moved outward by the thickness of the hat, but maybe I'm not seeing the whole picture.

I know that with several of the more popular ARP options, the knurl/shoulder length of the studs do tend to protrude through the rear axle flanges. The studs you pictured appear to be an OE replacement stud, but I can't quite make out the three digit number on the head to cross reference it to its application. Stock steel drum hubs up front will see the same thing...the nice thing is that most aluminum hubs have sufficiently thicker flanges that it's typically a non-issue.

Tobin
KORE3

OK, Moser says the studs are the same one they have always used. So it looks like some of the rotors / hats have a slightly smaller lug hole bore.

Michael informs me that we have also taken a cartridge roll to the lug holes in the shop for clearance. Shows you what I know!

No worries about going to large, the center bore will keep the rotor where it needs to be.

As for the wheels no slipping over the studs...that is a new one, but a tiny camfer on the lug holes with a burr bit would take care of that pretty quickly.

i had the same problem on my ats spindles with ARP studs.. the knurl on the studs protrudes thru that flange, simply chamfer the 5 holes in the rotor hat on the rear face and they will slip right on...