Brakes The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

[Mustang5L5]

The caged nuts are obsolete. Ford uses a different nut now, shown above, that has loctite on the inside.

fords official policy (at least from what I’ve seen) in all their newer vehicle service manuals is that ALL the hardware is one time use now, and must be discarded.

 

[TwoTone_89GT]

Alright everyone, I have a question. I have most of the parts I need to convert my '89 GT to five-lug/all disc. I have '95 GT spindles(new hubs, dustshields, and caps), 13" Cobra front rotors, and '02 GT rear disc setup with NRC brackets. I'm trying to figure out what front calipers to use and what MC/Booster combo would be the best match. I'm having a really hard time trying to find '03-'04 Cobra front calipers BUT I can get ahold of '97 Cobra front calipers. Would those work ok?

As for the car itself. It has a fiberglass hood, tubular k-member and coil overs, H/C/I with an Anderson N41 cam and will spend the vast majority of it's time on 17x4.5 front runners and 15x8's on the back with 275/50R15 tires. Later on I may pick up some "normal" street wheels. Thanks in advance everyone!

 

[Mustang5L5]

All 99-04 cobra, mach calipers are the same. I’m actually surprised you are having a hard time finding them as they are the most common casting these days given the earlier cobra caliper were discontinued earlier.

94-98 are 38mm x 2 piston.
99-04 are 40.5mm x 2 piston

If you get the 94-98 version, use a 94-95 cobra 15/16” MC and 93 cobra boooster or 94-95 booster

If you get the 99+ version, run a 1993 cobra master cylinder and the same boosters listed above .

 

[silverlx50]

So I need some help with my setup.

I'm running North Race Cars Big Brake kit up front with 94-95 Spindles. I'm running LMRs 17x8 Pony wheels, offset 19mm backspacing 5.25". The front wheels seem to stick out a lot further then I expected. Any idea of how to narrow the width a little? Are there different 13" rotors that may work?

For the rear, I have cobra rear brakes from North Race Cars and I have Ranger axles. I can't find a solid measurement on length but I think they may be a hair longer then Fox length axles. My rear tires rub the fender and its been rolled. I'll be tackling the Detroit Speed mini tub kit next month and wanted to see if there are other options along with fox length axles. Does anyone know the length difference between the Ranger and Fox axles?

FRONT

REAR

 

[Mustang5L5]

The SN95 wheels that are 17x8 use a 5.72”
Backspacing. So that’s about a 1/2” difference than the sn95 17x8s would pull in.

Ranger axles are the same lenght as fox axles. Only difference is the 5th lug. If they were longer the drum would not be located properly over the shoes.

Not a whole lot of options to pull your wheels in to be honest.

 

[silverlx50]

The SN95 wheels that are 17x8 use a 5.72”
Backspacing. So that’s about a 1/2” difference than the sn95 17x8s would pull in.

Ranger axles are the same lenght as fox axles. Only difference is the 5th lug. If they were longer the drum would not be located properly over the shoes.

Not a whole lot of options to pull your wheels in to be honest.

Nice thanks for the info. I was told Rangers were about 1/16" longer which is very very small. I have seen cars with my same rear wheel setup and theirs is tucked in a but more... I guess that's the world of modding...

 

[90sickfox]

It's the wheel offset that isn't correct for a 5 lug swapped fox. A different ( narrower ) tire size will bring the tire in more but they'd have the stretched look and I wouldn't advise it.

 

[KRUISR]

What tires are you running front and rear?

If you can, what is the dimension from the axle face to North Racing axle bracket?



This is a 16x8, 0 or 8mm offset with a 245/50/16 tire using fox length control arms and 96-04 spindle



Same rim and offset with a 255/50/16 tire and my OEM 4 lug axle.

I think you may have an SN95 axle in the rear.

 

[Mustang5L5]

Nice thanks for the info. I was told Rangers were about 1/16" longer which is very very small. I have seen cars with my same rear wheel setup and theirs is tucked in a but more... I guess that's the world of modding...

Ranger axle lenght is 29 5/32
Fox axle lenght is 29 3/16

That’s a difference is 0.027” it’s negligible.

 

[silverlx50]

So it looks like the Ranger axles vary depending on year. They were put on the car in the late 90s so could be one of the two different sizes.

Ranger axle lenght is 29 5/32
Fox axle lenght is 29 3/16

That’s a difference is 0.027” it’s negligible.

 

[Mustang5L5]

So it looks like the Ranger axles vary depending on year. They were put on the car in the late 90s so could be one of the two different sizes.

The only ranger axles recommended to be used, and the ones included in the ford racing 5-lug drum kit (discontinued) were the 83-92 axles, and only the LH side ( or RH ford Aerostar axle) In 1993 the Ranger axle grew 1” per side. Your going to notice a significant gap between drum and backing plate with 93+ axles.

The correct axle shaft has the part number E3TZ-4234-C and was what came in the Ford M-1126-A kit.


If you are unsure on what axle you have, pull the wheel and look at the drum gap, or perhaps even pull and measure and axle

 

[KRUISR]

If you have the 93 and up axles, that could explain you clearance issues in the rear.

 

[silverlx50]

The only ranger axles recommended to be used, and the ones included in the ford racing 5-lug drum kit (discontinued) were the 83-92 axles, and only the LH side ( or RH ford Aerostar axle) In 1993 the Ranger axle grew 1” per side. Your going to notice a significant gap between drum and backing plate with 93+ axles.

The correct axle shaft has the part number E3TZ-4234-C and was what came in the Ford M-1126-A kit.


If you are unsure on what axle you have, pull the wheel and look at the drum gap, or perhaps even pull and measure and axle

I will have to take a look.

 

[limp]

Converting over to 5 lug and wondering if the original 83 spindles and rotors, and calipers are even worth keeping??
Should I toss them??
Is the 7.5" rear end something someone could use??

 

[Wayne Waldrep]

Converting over to 5 lug and wondering if the original 83 spindles and rotors, and calipers are even worth keeping??
Should I toss them??
Is the 7.5" rear end something someone could use??

Don't be a dummy like me and toss Fox parts.
Somebody will buy them on eBay. Or need them on here!

 

[Mustang5L5]

There’s always a buyer, but I’ll be honest I don’t think there’s a huge population of folks looking for pre-86 brakes and 7.5” rears these days

 

[AeroCoupe]

I know this late but the guys over on www.foureyedpride.com are the 86 and down Mustangs, T-Birds, and Cougars so they may be looking for the 10" front brake parts and 7.5" rears.

 

[WDP327]

Anybody try brembo Cadillac ATS front calipers on the sn95 spindles?

 

[KRUISR]

Anybody try brembo Cadillac ATS front calipers on the sn95 spindles?

Lots of people. Just search for ATS calipers here.

I am about to do it on my sons 1989 GT that will be getting SN95 spindles - just not sure whether I will use 94/95 or 96-04 spindles. I have XTS brembos on my 90 GT with 96-04 spindles. The ATS ones install the same, just need to use smaller rotors than the XTS. We are planning to use 13.23" S197 rotors with the ATS/CTS calipers.

 

[86VertFinland]

5lugs...the cheap easy way.

Late model resto sells a kit for $400 to convert the basic 4-lug Fox into 5-lugs. Basically the kit uses OEM Ford components...in one easy kit with lube and misc items.


Basically, the requirements are as follows

Front (w/11" rotors): For the 87-93 V8 Mustang... 84-86 SVO or 84-92 Mark 7 front 11" rotors (either with or without ABS...doesn't matter)

Front (w/10" rotors): For the 79-86 and 87-93 4cyl cars, use the 83-92 4cyl Ranger front rotors

Optionally you can elect to replace the bearings at this time, or reuse the ones in your 4-lug rotors. Most often, they will directly swap over.

Rear: (All 4-lug drum rears) '83-'92 Ranger/Bronco II Left (driver) side axle (29-5/32") from a 4cyl or 3.0L V-6 with the 7.5" rear end, or '86-'97 Aerostar RIGHT side axles (29-5/32") is what you want. The 9" drums are off the 7.5" equipped ranger or aerostar.


Simple swap the axles and drums, and you are good to go.

Pros: Keeps stock fox offset up front and in the rear. Doesn't change a thing other than add a 5th lug. Cheap, Easy

Cons: Limited wheel selection. Front hub is the issue

List of the OEM Sn95 wheels that fit the front rotors without modification

94-96 16" Pony Wheels
94-95 17" GT wheels
94-97 Cobra 17" Wheels
1995 Cobra R wheels (OEM)
V6 Mustang wheels

Other SN95 wheels will bolt up, but you won't be able to run the center caps.

Hi! You had good info on swapping sn95 brakes to
79-86 fox. I have one stupid question.. i already have swapped 11” brakes and spindles from 1996 Mustang to my -86. Its still on 5-lug drums rear and master cylinder is original.
I just bought rear disc kit from foxbodybrakes.com (sn95 10.25”) eith one piston GT calibers like i have in front.
Does my original master cylinder work with these? I also bought new proportioning valve.. Or do i need a mc from svo, 1985 town car or 1993 cobra? I am confused..

Thanks in advance if you would be so kind to help..