Disc brakes not compatible with new axle studs, help please

[B0neCrush3r]

77 Restomod, Coyote with 6r80, 17" wheels BFG KO2 35s

I injured my hand and can't work on the Bronco.

I took the Bronco in for an oil change and to have my tech check a squeak in the rear expecting to have it back in a couple days...that was 6 weeks ago. The squeak ended up being a bent rear axle.

Ordered a new set of Yukon 31 spline 9 inch axles (Chris at Complete Off-road), studs are not compatible with my older (10yrs) wildhorses disc conversion kit.

I ordered these:
https://www.wilwood.com/BrakeKits/BrakeKitsProdFront?itemno=140-13305-DR
https://www.wilwood.com/BrakeKits/BrakeKitsProdRear?itemno=140-13323-DR
E brake part # 3026 at WH4x4

Wilwood stated a manufacture date of 2/28 even after I offered a case of Bourbon to speed things up.

I'm open to some alternative suggestions or if you happen to have a spare kit laying around I would love to buy them off of you.

I also find it odd that there is a compatibility issue, is this common? I searched and couldn't find much info.

Thanks,

Nathan

 

[Timmy390]

Too short? Too long?

Studs are pressed in. Change them out. PITA sure but it's part of the game

Tim

 

[duffymahoney]

How are the studs not compatible? The spline?

 

[duffymahoney]

I used Moroso 46180 also Arp-100-7703 works. Just fyi, both are much longer then stock.

 

[Rustytruck]

spline diameter oversize? ream the rotors to fit?

 

[B0neCrush3r]

Info sent to the tech, I'll post what he says.

Thank You

 

[B0neCrush3r]

He replied and stated the studs are incorrect for the gen 1/10yrs ago wildhorses disc brake kit.

The way the brakes and the new flanges are, the studs where the splines engage the flange of the axle have to allow the rotor to sit between them.

I'm not exactly sure what that means.....

 

[Rustytruck]

rotor conversions were done many ways in the past. cj 7 rotors were used and the went over the studs and over the flange of the axle. this required the outside diameter of the axle to be turned down so the rotor would go over the flange. there have also been situations where the rotors were mounted on the axle from the inside of the axle flange with the studs going through the rotor and then the axle flange. this was pretty rare since it would require machining the back side of the axle flange and there was the torino flange on 74-75 medium duty axles using the explorer axles and disc brakes. and there were the Lincoln Versailles axle swaps to get disc brakes. and I am sure there have been many more than that. go to the installer and video the problem with your phone and post the problem.

 

[B0neCrush3r]

Thanks for the reply. I'll get over soon and do that.

 

[Green_Bastard]

Is it because the rotor doesn't sit far enough back on the new axle flange for the caliper to fit over it?


Sent from my iPhone using Tapatalk

 

[Broncobowsher]

Aftermarket axle flanges thicker than stock. Is that the issue?

 

[Green_Bastard]

Aftermarket axle flanges thicker than stock. Is that the issue?

That's what I'm thinking. If so it's an easy fix


Sent from my iPhone using Tapatalk

 

[Quick & Dirty]

He replied and stated the studs are incorrect for the gen 1/10yrs ago wildhorses disc brake kit.

The way the brakes and the new flanges are, the studs where the splines engage the flange of the axle have to allow the rotor to sit between them.

I'm not exactly sure what that means.....

If the rotor is outside the flange, use the front drum studs (66-75 Bronco) Front studs have 3/4" length shoulder vs 9/16" for rear studs.

If the rotor mounts on the backside of the flange, use the front disk studs (76-96 Bronco)

 

[STalon89]

I had the same issue with my brakes and them making contact with the studs. Make sure your new axles are correct for the bearing size of your rear end (small large or medium duty) 77 is large I believe