Lower control arm touching rotor.
 

I have a speedway mustang to welding front end on our 1953 Chevy pickup. when you turn the tires the rotors rub the bottom of the lower control arm. why is this happening the bearings are attached to the spindles I didn't see anything that would space them out further does anyone know?

Re: Lower control arm touching rotor.
 

Both sides of the same thing.

Re: Lower control arm touching rotor.
 

The 11 inch rotor sits in a lot further than the stock 9 inch rotor does. At least according to the stock 9 inch one on this 66 MII fast back front end I have stashed out in the pile.

I'd think that a bit of diligently applied persuasion with a 2-1/2 pound hammer in the right spots and maybe a few touches with the grinder or flap wheel to get clearance will get the job done. A miss is as good as a mile there.

The inside face of the stock MII rotor is over 1 inch away from the control arm.

Re: Lower control arm touching rotor.
 

After looking at your photos a bit more and taking the liberty of putting them upright it looks like the big issue may be that lip on the inside of the rotor. There is no reason for that lip to be there and if you bought a stock rotor it wouldn't be there.

It would cost a few bucks to fix someone else's mistake but I'd take the rotors off and haul to someone with a brake lathe or lathe and have those ridges cut off. The only time you usually see a ridge like that is on rotors with a lot of miles on them that the pads have worn the rotor down (usually several sets of pads) and the rotors were never turned.

Re: Lower control arm touching rotor.
 

I'll look into new rotors. The setup only has about 100 yards on it . We turned it and I pulled it with my truck up my super steep driveway and that's what groved the rotors.

Re: Lower control arm touching rotor.
 

You don't need new rotors you just have to work on that lip of the control arm a bit and take just a little off the tin piece that holds the ball joint boot down. Just roll that end lip on the control arm back a tiny bit, dress it up with your flap wheel, shoot some spray can black on it and done.

Re: Lower control arm touching rotor.
 

I have the same setup: Speedway MII with stamped steel control arms and strut rod. I have no clearance issues. Speedway sells several different spindles for their MII kit; make sure they sent you the correct set. Ditto for the wheel bearings. No spindle bushings in that kit that might place the rotors out farther? Their online photo does show it's kinda close, but not as bad as yours:

https://www.speedwaymotors.com/Musta...les,22750.html

But yeah, worst-case scenario, have the rotors clearanced by a machine shop.

Re: Lower control arm touching rotor.
 

I'll call this week to see what they can do for me about it. The project went on hold I ordered the kit about 5 years ago so they probably won't send me anything free but I'll ask about a discount if it's not my error.

Re: Lower control arm touching rotor.
 

By looking at this shot taken from an old article on how to install a MII front end on your 54 Chevy car brake rotor clearance has been an ongoing issue with stock lower control arms.

Re: Lower control arm touching rotor.
 

We just got hit with snow. But next time I'm out there in the shop I'll grind the heck out of it. Then post some pics. I just want to make sure I'm not creating an unsafe situation before going forward.

Re: Lower control arm touching rotor.
 

Speedway's site shows about 1/4" clearance between the arm and rotor - close but definitely more than the OP has in his pics. On their site you can enlarge this photo.

Re: Lower control arm touching rotor.
 

I dont see any calipers mounted yet? Have you tried fitting the calipers? If they dont fit over and center up on the rotor, you might have the wrong rotors and causing the offset to be inboard to much.

Re: Lower control arm touching rotor.
 

From 2006 Read down the page! As I said before, this has been an on going issue with stock MII/ Pinto lower control arms from the get go. https://www.hotrodders.com/threads/l...pension.93743/

Also read down this page. Where it clearly states that you have to grind the end of the control arm for rotor clearance. https://vr6coilbracket.com/Mustang-I...tors-p50694270

Re: Lower control arm touching rotor.
 

in the streetrods we build, we use 76 Granada rotors and Gm calipers on the mustang II frontends and dont see that collision. Good luck

Re: Lower control arm touching rotor.
 

Replacing the rotors with new ones is not going to solve your problem. What I would do is take your rotors to a machine shop and have them turn the rotors and remove just a slight bit off the inner part of the rotor where it hits the lower control arm.
Vic

Re: Lower control arm touching rotor.
 

Not necessary if you read the two links I posted above. This isn't some new rare thing that just happened to him with the rotors he has, it was a very common deal when guys were all using the oem MII control arms before tube A arms started showing up. You reworked the control arms a bit for clearance and were all good and away you went. No looking for the "right rotors" no dinging around with other mods.

At first look it looked like who ever had machined the rotors originally had left a ridge on the inside of the surface. A ridge that would be beyond the area the pad contacted. That may be because of the groove the a arm cut in it. I'm thinking that that is still in an area that the pads don't touch.

Still it is a five minute job to do exactly what they said to do in the Welders series link and be done with it. That is what everyone has done in the past.

rand: Welder Series
Thickness: 3/8"
Brake kit for 1974 -78 Mustang II and 1974 – 80 Pinto/Bobcat spindles. This kit adapts larger 11″ Granada rotors and 1982 – 92 Camaro (or equivalent) calipers for a simple, effective, and inexpensive brake upgrade. Some 14″ wheels will clear the calipers. 15″ wheels will clear. The 1975 – 80 Granada rotors move each wheel out 1/4″ from stock Mustang II rotors.

The stock Mustang II dust shield must be removed from the spindle and discarded. The Granada rotors fit onto the Mustang II spindles using stock Granada bearings, seals, outer washers, nuts and dust covers. Stock Mustang II spindle nuts can be used.

The end of the lower control arm must be ground away for rotor clearance. DO NOT INSTALL THE ROTOR UNTIL THIS CLEARANCE HAS BEEN ESTABLISHED. 1/8 inch clearance is enough.

Use stock brake pads (#7070A or FMS #D154) for the calipers.

NOTE: The squealer tab on the inside brake pad must be bent 1/8” toward the rotor surface. This can be done by carefully tapping it with a hammer. The outer pad tabs may need to be bent slightly to tighten the pad on the caliper. This will keep the pads from squeaking.

Stock GM calipers have a lip around the brake hose port. Grind this lip and rotate the hose fitting so it clears the coil spring when the steering is at full turn lock. Be sure the brake flex hoses do not touch wheels, tires or any other parts under any suspension travel or cornering conditions.



Be sure to read the installation tip sheets shipped with each kit.