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Watts link vs. PHB question

I will come out and say that this probably doesn't entirely belong here as it doesn't pertain entirely to Bosses specifically. My dad and I have a project car that we road race, an 86 Fox, and there is an issue with the rear in it, under hard corners the brake pad rubs on the rotor. I know this happens because the rear allows a certain amount of movement from the axle into and out of the housing. I haven't experienced this on my car, so assume Ford has found a way to correct this. My question is: does this partially occur because the PHB allows for more movement side to side of the axle, and if so could it be remedied by a watts link. I only ask on this forum as it seems to have the most people on it that are proficient in car racing and setup.
 

TMSBOSS

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My dad and I have a project car that we road race, an 86 Fox, and there is an issue with the rear in it, under hard corners the brake pad rubs on the rotor.

The movement of the rotors relative the calipers has nothing to do with a PHB or Watts link system.

The movement of the axel shaft and therefore rotor is related to the axel bearings and or the tolerance at the c-clip at the end of the axel. Also in the mix can be the condition of the limited slip clutch packs.

Swapping from PHB to Watts link will do nothing to stop the movement described.
 

pufferfish

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the brakes are firmly attached to the axle housing, which is what the phb or watts controls. if the axle shaft is moving in and out, changing the lateral control method will do nothing to change it. there should be a marginal amount of end play, but excessive amounts can cause this. there are only 3 parts that can cause excessive end play in an 8.8 solid axle. the axle retaining clip could be too narrow, the retaining pin that goes through the diff and goes between both axle ends could be too narrow or worn, or the clip groove machined into the axles could be in the wrong place.

that said, I thought your dad was telling me he swapped in an entire terminator drivetrain, which I thought included the IRS?
 
Didn't include the rear, we have been thinking about it but figured for the price we could do a watts link and torque arm and probably fix the rotors rubbing.
 

pufferfish

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ahh, I see. I think the solid axle is better anyhow. you should check the amount of endplay you have. do both axles have the same amount? I don't know what the acceptable limit is, but it can't be more than .020-0.30" if I were to take a guess? what brakes are you using? did you install the anti-moan brackets if they were factory ford?
 
I remember hearing a rattle from the rear end of my instructor's spec miata. he mentioned that he didn't use the anti-rattle springs that hold the pads in place and pull them back once brakes are depressed. Were the metal springs used on your car? They may require replacement as well, since they wear down and loose tension.
 
Stock single piston rears, Baer twin piston fronts. I think my dad had C clips made at some point but they didn't fit for some reason. I think my dad said its 20 thousandths movement. Where did you go Steve to have your rear end aligned after your DS install?
 

pufferfish

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I did the alignment. I had JPC change the gears out.

if the axles are within .020", the next thing I would look at is a sticking caliper slide pin.
 

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