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SN95 5-lug conversion

Under the Hood    -    Rear Brakes    -    Front Brakes

For the rear brakes, there are two routes that you can take if you are going to be using 94-up Mustang parts. The 1st is to get 94-04 GT/V6 rotors/calipers and the 2nd is to get 94-04 Cobra rotors/calipers (There are also other brakes you can get from a Lincoln or Cadillac but I have not researched that route and this article will not be documenting those options). I found a pretty good deal on non-Cobra hardware, so I decided to go that route. The setup includes 10inch solid rear rotors from a 94GT along with 99GT 38mm single piston Varga calipers. You can go ahead and use any 94-04 Mustang rear rotors and calipers but be certain that you don't try to mix and match Cobra and non-Cobra parts. The Cobra used 11.65" vented rotors and Cobra specific calipers. Also, be certain that you do not try to use Cobra specific anti-moan brackets with non Cobra brakes, and vice-versa since they will not fit. Some have also used 99-up anti-moans with success, but I had a bad experience with them and recommend using 94-98 anti-moan brackets for reasons that I will discuss further in the article.

 The next order of business that I should discuss is axle length. If you are going to be using Ford 17x8 rims with 5.72" BS (like most factory 17x8 5-lug Mustang/Cobra rims) and no wider than a 255/45/17 tire, I highly recommend the SN95 GT/V6 axles (94-98). These axles are 0.75inches longer than the stock 87-93 axles and they stick out just enough to give it max wheel cleavage (as I like to call it) without posing a fender rubbing problem. Even on a lowered car, you should not have to roll your fenders in any way. I have heard of some rare instances of people having to lightly roll the fenders or grind a little of the fender lip, but I have had no problems at all, even with two people in the car along with a lowered suspension. You can say good-bye to the rear wheel  in-board problem if you use these axles. Here is a comparison of the stock axles and the sn95 axles side by side (note the length difference).

 

*Sidenote: If you currently have 16x7 Pony rims (4.91" BS) and stock 87-93 axles and you want to know how much further your wheels will stick out with a 17x8 (5.72BS) rim with sn95 axles, here is the math.

First the axle will push the wheel out by 0.75" on each side.

Next, the Pony rim has a distance from the vertical mounting reference point to outer wheel lip of 7 - 4.91 = 2.09 inches. The 17x8 Ford rim has a vertical mounting reference point to outer wheel lip distance of 8 - 5.72 = 2.28 inches. Therefore the 17x8 rim will stick out 2.28 - 2.09 = 0.19" more than the Pony rim if the axle length were the same. So if you combine the two lengths: 0.75" from the axle and 0.19" from the rim, each rear wheel will stick out 0.94" inches further than it did on each side with the Pony rims and stock axles. So if you go to the rear of the car and measure from the outside of your drivers side rear wheel to the outside of you passenger side rear wheel, you will measure a difference of 1.88" (wider) than it was previously. It sounds like a lot, but I have been running this combination with no problems whatsoever, on a lowered vehicle.

 

If you decide that you want to use a 17x9 rim, I would make sure they have at least a 6.42inch backspacing in the rear if you are going to use sn95 axles. Because very few popular rims come with that large of a backspacing, you will likely be better off finding a set of stock 87-93 length 5-lug axles that could be taken off of an '83-92 Ford Ranger pickup or Bronco II (driver side only) from a 4cyl or 3.0L V-6 with the 7.5" rear end, or '86-97 Ford Aeorostar Van (passenger side only). The stock axle length is 29 5/32". So make sure to measure them for that length and 28 splines if you are getting them used. If you are going to use sn95 rear disks with these stock length 5 lug axles, you need a non-factory caliper mount that is carried by "North Coast." (http://www.northcobras.com/catalog/brakes/brakes.htm)

The 94-up Mustang caliper mounting brackets will not work with this length axle. You also should take quad shock clearance into account.

 I do not recommend using 99-up Mustang axles because they are too long (1.4" per side) for most applications. There are also some Lincoln axles that will also fit, but will place your wheels much too far out (1.25" on each side). Here is a pic of a fox with Lincoln axles:

 

The idea is, decide on what rims you want to use, and get the brake parts according to that.

 I began by jacking up the rear, placing the rear subframes on jackstands, and wedging a piece of wood between the front tires and the ground for safety.

 

Once you remove the rear wheels, and have the rusty drum staring you in the face, you really begin too appreciate the work you are doing, even if it is to just get rid of those hideous drums.

 

Making sure that the e-brake is not set, slide the drum out from the axles studs. You may have to gently tap it with a rubber mallet. Next you will see the inner drum brake maze. If you have ever done a drum brake job, you know how many parts there are and how time consuming it could be. And for what? Ancient technology?

 

At this point we can go ahead and remove the axles. Place a large container under the rear end and loosen all the rear end housing cover bolts. I made sure to leave the top three bolts slightly in. Then pry off the cover with a screwdriver until the gear oil begins to drain. Once it is fully drained, remove and clean the cover. Also clean the surfaces that the cover contacts since this increases the chances of getting a good seal once you bolt everything back together.

 Rotate the rear wheels until the 8mm bolt holding the pinion shaft is exposed. Put the car in gear, and remove this bolt. Be careful to keep the 8mm socket flush against the bolt to avoid stripping it. It helps to use a 6 inch length, 3/8" head extension here. Once the bolt is removed, you can slide the pinion shaft out.

 

Now, put the car in neutral and have someone press in one of the axles. This will expose the c-clip which you can slide out using some needle nose pliers. You may have to rotate the axles in order for the c-clip to be oriented in such a way that they can slide out. Once the C-clips are removed, slide the axles out from the rearend housing. Be very careful not to damage the bearings or ruin your axle housing seals. It may be a good idea to replace the seals at this time since you have everything apart and they are cheap. Mine looked to be in very good condition so I left them alone.

 

I just started to collapse and undo all the drum brake parts, including E-brake cables until all that was in front of me was the axle and rear drum mounting plate. Remove the four bolts that hold that on and pull the drum mount off towards you..

Now you are ready to install your caliper mounting brackets. Reuse your existing hardware from the drum mounting plate and tighten all four bolts evenly. The new sn95 axles, are not side-specific, so grab one and gently slide it into the axle housing. Have someone, once again, push the axle all the way in which will allow you to install the c-clip. Once the c-clip is in, pull the axle out gently, and you will hear it click into place. After both sides are done, reinstall the pinion shaft and bolt. The 8mm pinion shaft locking bolt requires a bit of RTV and a torque spec of 15-30 foot pounds.

 

Place a bead of black silicone (RTV) around the rearend cover and bolt it back onto the rearend housing. You should wait a few hours for the silicon to fully dry before putting in gear oil and 4oz of friction modifier. Use 80w-90 or 75w-90 gear oil. The fill plug is on the top-front of the housing, and it can be removed using the end of a 3/8" square extension. I used a hand pump to fill the housing until I saw fluid spilling out of the hole.

 You are now ready to slip on the rear rotor and secure it using a wheel bolt.

 

It is important to know that the rear disk caliper pistons "rotate" out, NOT "spread" out. You need to by/rent a tool from your local autoparts store. With the pads removed, rotate the caliper piston out just enough so the caliper just barely slides over the rotor when it is loaded. You may want to put some anti-squeal lube on the back of the pads. I did not, and have no unwanted noises at all.

 

Next up is the subject of anti-moan brackets. I had someone send me some brackets that they claimed were from a 99GT. When I tried to install them, I noticed they were too short in length if I tried to mount the U-bolt thru the shock mounting bracket. If I placed the U-bolt on the outside of the shock mounting bracket, the anti-moans didn't quite fit, but I could have bent them slightly to make them fit. I have seen pics of people making these 99-up brackets fit with some force, but I decided to get rid of them and buy some correct length 94-98 anti-moan brackets which fit perfect.

 

Make sure to install the anti-moans without tightening the U-bolt nuts completely. The caliper mouting bolts are to be tightened down first, followed by the two anti-moan U-bolt nuts.

 Now you are ready to drill mounting holes for the rear brake lines. I bought my brake lines brand new and specified "95 Mustang GT" at the parts store. You will notice that the brake lines each have a metal bracket with a mounting hole already in it along with an alignment tab. Use these brackets as templates for where you need to drill your holes. The tab requires a 11/32" drill bit, and the actual mounting hole can be made using a 9/64" bit. You will need to find two nuts and bolts of the appropriate size. For the brake line brackets. I cannot tell you what size nuts and bolts I used because they were found at the bottom of my tool box, trial tested, and found to fit.

 

In order to attach the stock hardlines to the softlines, you will require a single Weatherhead 7818 adapter per side. These can be purchased at your nearest Napa Autoparts or Carquest. Just for your reference, I could not find them at my local Kragan and Autozone.

Attach your softlines to the rear calipers using your banjo bolts and copper crush washers, placing a washer on either side of the brake hose, where the banjo bolt goes through.

 On the opposite side of the softline, you will notice that your hardlines are too long when you try to attach them and they either need to be cut and re-flared, or bent into an "S" to take up the slack of the extra length hardline. I originally planned on cutting and re-flaring, but thought I'd at least give bending them a shot since it was easier. I had a tubing bender to get me started and I used a large socket for final adjustments to avoid putting any kinks in the lines. If you do it this way, make sure to bend the lines out of the way of the rubber snubbers. I will fully admit that this is not the best way to go about shortening the lines, and it doesn't look the best, but it does work just fine. If you have the resources to cut and re-flare, then by all means do it.

 

Now you are ready to remove the existing emergency brake cables. On a '93 car, all you need is the '93 Cobra brake cables, and nothing else. Nothing needs to be welded or modified in any way as many people seem to say online. Simply disconnect the stock e-brake cables from the bracket in the transmission tunnel (I cut mine with a dremel, and made sure to remove the driveshaft to give me more room to work with. Some people say that a 13mm box wrench works great on the three little tabs too). There is also a single holder that keeps the cables against the underside of the car. Just route the new cables in exactly the same way as your old cables were routed and secure them using this holder, one on each side. You may need to have someone pull on the equalizer a bit to give you enough slack to attach the ends of the cables to the rear caliper e-brake mount. Make sure to use the ebrake brackets that attach to your lower control arms. These will keep your ebrake cables from rubbing on the tires. They can be taken from any 94-98 Mustang.

 If you have a 87-92 Mustang, you will need the following e-brake parts:

M2809A (2) rear cables
M2810A (1) center e-brake cable

Page 3: Front Brakes