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SN95 5-lug conversion

Under the Hood    -    Rear Brakes    -    Front Brakes

I originally thought that the front brakes were going to be the part that I breeze through in this conversion, and if I could do it over again, I would have done just that. The story goes as follows. I jacked up the front of the car, set it on jack-stands, removed the wheels, and started pulling off the original brake parts. As you can see, the previous owner of my car installed cross drilled and slotted 11 inch rotors with Performance Friction Carbon Metallic pads. I don't know how much this combination improved braking compared to stock, but I can undoubtedly say that this car stopped significantly better than my 100% stock 93GT. I will admit that part of this is attributed to the weight difference between the two cars.

First, undo the sway bar end-links. Then, disconnect the caliper soft-line from the inner hard-line by prying off the U-shaped retaining clip and using a flare wrench to disconnect the brake fittings.

Next, remove the calipers by taking out the two caliper mounting bolts and wiggling the caliper loose off the rotor. Then, wedge a screwdriver between the rotor "hat" and the grease cover in order to pry the two apart to gain access to the large spindle nut that keeps the caliper from sliding off the spindle shaft. Remove this nut using a large monkey wrench or appropriately sized socket. Be careful not to let all the wheel bearings and associated pieces from sliding out. I usually slide out the entire rotor out while keeping my thumbs pressed against the bearings. Then I place the rotor flat against the ground and gently tap the grease cover back in which ensures that none of the bearings fall out. At this point, here is what you are looking at:

Here is a picture of the old brake parts which I sold on ebay to help offset some of the cost of this project.

Now, remove the tie-rod cotter pin and castle nut. Use a pickle-fork to disconnect the tie rod stud from the spindle. Be careful not to damage the grease cover.

There has been some controversy over whether or not the SN95 spindle offers a lower bottom strut mounting point than the stock 87-93 spindles. Although it is difficult to see from the pics, I had a family member hold the two spindles side by side, with both spindle axis' in a single line, and I measured 0.5" lower bottom strut mounting point for the SN95 spindles (in the vertical direction). This measurement is likely irrelevant to people using 87-93 struts, but if you are using the longer 94-up struts, every little bit counts to help prevent the longer struts from bottoming out.

Here is where things started to diverge off the path that I laid out. Begin by loosening the two lower strut bolts, but do not remove them at this time. Next, position a jack under the front control arm (make sure that the jack is under the arm, but leave about 1/4" of space between the jack and the a-arm). In the pic above, you can see the spindle castle-nut and cotter-pin. Remove the cotter-pin with a set of needle-nose pliers and unthread the nut. Before I reveal the method that finally worked for me, I'd like to tell you what NOT to do. Also, please keep in mind that everything I say here, is my personal experience. I know some people may have used one or more of these methods successfully and might want to argue that I don't know what I am talking about. There may be someone out there that disconnected their spindle from their ball joint using their teeth even. Point is, the following is a documentation of what worked and what didn't work for ME on MY car. (:

I began with a regular carpenter's hammer and repeatedly struck the top of the balljoint stud from the top with no success. A friend of mine suggested I try using a 3-2 Jaw-puller (2-ton) from Autozone. The result was that I snapped it under load. It snapped so easy in fact, that I didn't even bother trying the 5-ton Jaw-puller since I didn't want to snap another $35 tool. The next idea I had was to go rent a large pickle-fork from Autozone. Armed with the largest pickle fork known to man, I went to work. The result was a pickle fork with the teeth broken off as well as trashed balljoint grease covers!!! I have yet to hear of anyone on this planet snapping a 1 1/16" U-pickle-fork, but somehow I managed it. About now I am thinking maybe someone glued these balljoint studs into the spindle. Because I FUBAR'd the stock balljoints, I went and ordered a new set of FMS (M-3075-A) front control arms. I didn't realize it until I received them, but the bushings are significantly stiffer than stock and allow for tighter "real-time" alignment specs since worn control arm bushings cause the alignment specs to change significantly when the front suspension is under extreme load such as braking, hitting large bumps, or taking aggressive turns. It can also be altered when the front suspension is under reduced load such as launching or during the "rebound" after hitting a bump.

While waiting around for my new A-arms to arrive, I did a little research and found that a good way to break the spindle loose from the A-arm is to use a large 5lbs hammer and alternate the striking points. Begin by giving it a few swings from the top, then from one side, and lastly from the other. Hitting it from the side seems to be the secret of this task. Much to my delight, alternating this series of hits a few times broke the spindles loose (now you can remove the two strut bolts and slowly lower the jack being careful not to let the spring shoot out). Now I was able to install the new A-arms that come with brand new balljoints. *Note: New Ford Racing A-arm bushings are very stiff so it takes some finagling with a pry bar to get the holes to line up.

Now you are ready to place the new SN95 spindle on the a-arm. Before you install the castle-nut, make sure to first place the 0.330" spacer (5/8" ID) on top of the spindle to prevent you from running out of threads when you attempt to tighten the spindle castle-nut. You can have the spacer machined out of steel at a machine shop or make a post on www.corral.net/forums about this and you should get a response from one or two people who sell these spacers there. That is how I got mine. Unfortunately, Ford Motorsport does not sell these individually and I don't know of any stores that sell them ready to be used. Another option is to use washers that total about 0.330" in height when stacked. Be sure to tighten the castle nut to 110-150 foot pounds and place the cotter-pin back in for safety..

Keep in mind that if you do not replace your A-arms, don't ever allow your stock A-arms to drop all the way down, unloading your springs. This way, you don't have to go through the trouble of having to get the coil spring back into the perch (by using a spring compressor or dropping the inside of the A-arm once the strut is connected to the spindle). Once the coil springs are installed, if you try to connect the tie rod to the spindle, you will notice a large amount of "toe-in" in the alignment of the car. The car likely cannot be driven like this since the two front tires will fight each other down the road. In the pic below, you can see the excessive toe-in.

What you need is to loosen the tie rod locking nut and undo the tie rod end about 6 turns from the "rod" in order to straighten the front wheels. Once you ballpark the alignment, then you can at least drive the car to the alignment shop for a professional alignment. Remember, the front of the car tapers, so you don't want the front wheel flush with the fender. With the steering wheel straight, try to align the front wheels as close with the rears as possible. Once you have the alignment dialed in, tighten the tie rod locking nut, put the tie rod stud into the spindle, torque the castle-nut to 35-47 foot pounds, and install the cotter-pin. Also, install the sway bar end-links as well as the strut to spindle mounting bolts (torque to 140-200 foot pounds).

Now the fun part starts! Grab one of your 13 inch rotors, slide it on the spindle and tighten it down with one or two of your old wheel nuts. Don't forget that some of the Cobra rotors are side specific. There should be an "L" or an "R" on the inside of the rotor. Next, slide the loaded Cobra caliper (also side specific) over the rotor and spindle mount, and tighten the caliper bolts to 75-90 foot pounds. Just for your own reference, L and R correspond to the sides looking from the back of the car to the front. So L = driver side and R = passenger side.

Now you are ready to attach your front Cobra brake hoses. I got mine from a '95 Cobra. The drivers side soft-line to hard-line attaches directly while the passenger side requires a Weatherhead 7828 fitting. I bought my copper crush washers directly from Ford. You need two per side. Torque your banjo bolt to 30-40 foot pounds. After you tighten up the fittings, do not forget to re-attach the locking U-bracket which keeps the brake lines in place.

At this point you are ready to bleed the brakes. It is always a good idea to begin by bench bleeding the master cylinder to ensure that there is no air stuck in it. After you finish bench bleeding, and the MC is in the right place, fill the reservoir up with DOT 3 or 4 brake fluid, and bleed each caliper (starting from furthest from MC to closest - PR, DR, PF, DF) without letting the reservoir run dry. If it runs dry you have to start all over. Make sure that you have no leaks. Generally, if you have no leaks and a soft pedal, it could mean that you have air in the system or that the MC is bad. If you have a hard pedal, check to see that the vacuum hose is attached to the booster, check the angle that the pedal shaft is going into the booster, and check to see if the brake switch is getting hung up on the pedal. Just as a side-note, I installed a brand new Cardone 95 booster and I had a rock hard pedal. I was almost ready to tear the thing down before I decided to try one more thing. I took the car out and did a series of hard high speed stops. After a few of these, the pedal started to feel normal and the car was stopping as I would expect a sports car to stop. Maybe there was a bit of grease on the rotor or maybe the booster diaphragm popped into place. I don't have a particular explanation for this, but who can argue with a working product?

And the finished product:

Some Notes:

When you do your alignment, for a street car I recommend:

-0.75* camber, max caster that your plates will allow, 0-toe. This has resulted in excellent tire wear in my car. Also consider that my car has brand new front control arm bushings and a solid upper strut mounting hole which will help maintain alignment during the stresses and changing suspension load characteristics while driving.

This project, for most people, is not just a weekend worth of work. If you have a second car, and ample time, this could be a fun project with big rewards. But if you fully expect to wrap this all up in a weekend, you may have great frustration ahead of you. I am not saying it cannot be done, but if you are working by yourself in the garage with jack-stands and hand tools, it is highly unlikely.

One subject I have been reading about is the bump steer issue that can be introduced with sn95 spindles on a lowered fox due to the tie rod coming up to meet the spindle at such a significant angle. I can report that I have detected zero bump steer since my conversion, even with my lowering springs. If you do have problems with this, you may need to get a bump steer kit which will put your tie rod back down.

I must report that the car stops incredibly well. There is virtually zero brake fade that I could sense, even during hard high speed stops. I have spoken to a few people who have Cobra brakes up front and GT/V6 10 inch disks in the back like myself, and they reported that their cars seem to like equal bias front/rear (adjustable proportioning valve turned all the way in). My car is the same way. Even if I have full bias to the rear, my back tires will not lock up before the front.

If you have any questions, please feel free to ask. If you ask me questions that are fully covered in this write-up, I will likely direct you to the corresponding section. Thanks for reading and I hope this write-up helps you in your swap.

Thank you.

Luke

info@mustangmotorsport.com