1989-1992 Spindle Faq - Error Check,Additions

Mike8675309

Registered User
Here is the Faq I created based on the last few threads. Please check for errors or corrections and then we can try to get it added to the FAQ section:

1989, 1990, 1992 Front Brakes and Spindle FAQ

What Brake Mods are available with STOCK front Spindles(1989-1992)?

None. The spindle design on the first years of the SC were changed in 1993. The 1993+ spindles are very similar to the Ford Mustang. And since a ton more Ford Mustangs were built, that's where the brake mods can be find. So if you want those trick dual piston front calipers, or those bigger Mark VIII brakes, or even bigger KVR brakes. You need to change out the front spindles to those from a 1993+ Thunderbird or Mercury. An SC part is not necessary.

Do I need to swap the front Hubs If I swap the Spindles?

No, the 89-92 hubs will bolt onto the 1993+ spindles. But there are some issues to consider:

The 89-90 hub does not have a machined lip to support the center of the brake rotor. The 91+ hubs have a machined lip to help center the rotor that fits a larger opening on the brake rotor. That means a 89-90 rotor won't fit on a 93+ hub, but a 93+ rotor will fit a 89-90 hub but won't gain the support of that machined lip.

A replacement 89-90 Hub is around $200. A replacement 91+ hub is about $75.

So the story here is you can retain your 89-90 hub if it's in good shape. But when it's time to replace it, move to the 91+ and get some new rotors. And if you're getting new rotors now, get the 91+ rotors. (Any of the upgraded brake rotors should be for a 93+ already)

What is the biggest brake I can fit with STOCK wheels?

The largest brake rotor size is from a Mark VIII car at 11.57". The downside to that choice is that it's only available with the Mark VIII caliper which is single piston. The increased surface area of the rotor will help disappate heat quickly, but you won't gain the increased clamping force of a dual piston setup. Not a must, but certainly handy if you want to do any type of road racing.

Stock rotor diameter is 10.9"

What is the issue with the 1989-1992 Spindles?
Below is a picture of the 1993+ spindle on the left, and the 1989-1992 spindle on the right. Notice the tabs sticking out on the 89-92 that are used to retain the brake shoes. In 1993 it was changed out to a bracket that bolts on. These are the major items that prevent a larger rotor, and dual piston calipers from fitting on them. Yes you could cut them off, but notice the reduced material around the bolt holes for the caliper brackets. Remember, you're messing with your brakes here.

spindlecomp.jpg


Thanks to George Davenport (gldiii) for the pictures and information and Rich Thompson from www.MN12Performance.com for his information and heads up on a deal on PBR dual piston calipers and Ed Nicholson(fast Ed N) for his detailed information.

Edits:
Fixed Ed's lastname spelling.
 
Last edited:
Looks good Mike, except you spelled my last name wrong !! ;)

It's Nicholson, like Jack, except I'm not quite as mean or talented, or rich for that matter. :p


cheers
Ed N.
 
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