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Discussion Starter #1
I just had installed a 31 spline FRPP differential with the carbon fiber clutch pack and some Alloy axles and they are too long. I had to shim the caliper brackets about 1/8" to keep them from rubbing the rotors. Wazup widat? Also because of the longer axle the ABS pickup is only about half way over the exciter ring. Is the ABS going to work?
 

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So the diff and axles are both new?
Anything different about the C-clips or how they seated into the side gears?

That's a little crazy....
 

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Is this a fox? Maybe you have sn95 axles and that's what's pushing them out
 

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Discussion Starter #4
Is this a fox? Maybe you have sn95 axles and that's what's pushing them out
2003 mach1 and the axles are for 99-04 and the part #s are correct. The only thing I can figure is that the mach1 uses the thicker and vented Cobra rear rotors. All other 99-04 Cobras are IRS. So maybe Alloy didn't pick up on the difference or didn't want to make a different axle for such a small run of cars.
 

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If you went from a 28 to 31 spline differential, that is the main problem. The 28 spline differential uses a 0.75" pin. The 31 spline differential uses a 0.875" pin. None of the aftermarket companies I've ever seen compensate properly and make their 31 spline axles shorter to compensate.

Get some precision shim washers and put them between the caliper hanger and axle bracket.
 

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If you went from a 28 to 31 spline differential, that is the main problem. The 28 spline differential uses a 0.75" pin. The 31 spline differential uses a 0.875" pin. None of the aftermarket companies I've ever seen compensate properly and make their 31 spline axles shorter to compensate.

Get some precision shim washers and put them between the caliper hanger and axle bracket.
So the 31 spline side gears are pushed (approximately).062" to the outside compared to 28 splines? Learn something new every day!
 

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Discussion Starter #9
If you went from a 28 to 31 spline differential, that is the main problem. The 28 spline differential uses a 0.75" pin. The 31 spline differential uses a 0.875" pin. None of the aftermarket companies I've ever seen compensate properly and make their 31 spline axles shorter to compensate.

Get some precision shim washers and put them between the caliper hanger and axle bracket.
Yeah that's what I did and your answer certainly makes sense.
 

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Discussion Starter #10
If you went from a 28 to 31 spline differential, that is the main problem. The 28 spline differential uses a 0.75" pin. The 31 spline differential uses a 0.875" pin. None of the aftermarket companies I've ever seen compensate properly and make their 31 spline axles shorter to compensate.

Get some precision shim washers and put them between the caliper hanger and axle bracket.
Thanks Jack. Also, will I have any ABS problems since the pickup is no longer completely over the exciter ring?
 

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.067 inches is insignificant. It is about 1/16th of an inch.

It sounds like your axles are a tad too long out to the flange, along with that 1/16th inch.

What did the axle manufacturer say?
 

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Discussion Starter #12
.067 inches is insignificant. It is about 1/16th of an inch.

It sounds like your axles are a tad too long out to the flange, along with that 1/16th inch.

What did the axle manufacturer say?
Mfg said it's the correct axle. So it's a combo of what Jack said and what I said earlier about the mach1 having thicker rotors than all the other straight axle 99-04 SN95s. It took a 1/8" to get acceptable rotor clearance and now the ABS sensor is only about 1/2 covering the exciter ring.
 
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