Should I Tack-weld My Nrc Caliper Bracket To The Axle Flange

Discussion in 'Fox 5.0 Mustang Tech' started by 1200gt, Jun 4, 2013.

  1. These are questions that speak to the various ways to do a 5-lug REAR brake conversion, more specifically where STOCK LENGTH axles are being use in conjunction with 94+ rear disc setup on an 8.8.

    I have an 86GT and this process for this year is not much different from the Fox cars up to 1993.

    I have come across a couple ways to do the "bracket conversion."

    1) Use North Race Car (NRC) caliper brackets, which I understand are a little thinner than OEM pieces, at least in the main body of the bracket. OEM bolt-hole-counter-sinks are 3/16" - about the same thickness as the whole NRC piece.

    2) Use the OEM caliper brackets, but with a section cut out of them to allow them to be mounted in-board on the axle flange - thus requiring a few washers to get all aligned.

    The later option leaves some weakness issues in the caliper bracket as they are no longer one solid bracket.


    It speaks to both options:

    Can I tack-weld either of these brackets to the axle flange after I have mocked up everything an assured there are no interference issues or other anomalies like squeaks etc.?

    I would do this to add strength to the brackets in either option.....
  2. Do the second method and then weld the cut out section back onto the rest of bracket. I did the second method but didn't bother welding the cut out section back on and honestly I'm not even worried about it.
  3. There are no strength issues with the NRC brackets. I ran them on my car for years. The bracket is only holding the rear calipers, which don't do a whole lot of braking anyway.

    Just bolt on the NRC brackets as they are designed and call it a day.
  4. i have NRC brackets and there will be no issues with strength or longevity
  5. I may be wrong about this, but i believe the oem brackets are cast iron, whereas the NRC brackets are made from a stronger steel. Probably why they can be thinner. I also used the oem brackets, no welding, and no problems thus far.

  6. It seems as if no one has had any issues going either way as I read these few responses.

    As it turns out, I have two sets of the rear OEM Caliper Brackets that I would love to put to some good use.... maybe even sell them it I can get a value set. Note: If I use one of these I have to spec-in some washers for alignment following thru on the in-board installation method.

    On the other hand, the NRC brackets need no washers added to the kit and mount-up on the outboard side in the OEM location. However, they are about $$$160.00 per set.


    This information will no doubt go towards helping others who might be on a TIGHT budget to make decisions on this issue. Fortunately, I am blessed at-this-moment to be able to afford the NRC pieces. Being that I am conscious of my $$$, I would take advantage of the option to cut the OEM pieces if I can certainly determine there is no exaggerated safety risk doing that modification.

    TACK WELDING this method seemed to be an added safety modification to insure no movement or flex..... I guess no one has done this to there setup????

    So, my decision is still up in the air right now. I have a little more time before I start on this mod. But as I read these comments, it seems I would be alright doing either method if I choose, even without any Tack-welding of the either of the bracket offerings. Talk me down if you believe otherwise...

    Any more comments or experiences with this MOD? Certainly a newbie to Fox Cars will find your ideas useful. I've read post on this issue dating back to 1994... that still live to pass on great ideas. Albeit on another site, this Cut-Caliper-Bracket-Method being one such Thread - One Poster has his name up in lights so-to-speak. When you google certain aspecs of this mod, his entire build dominate google images; he has a Capri if you are interested.

    Anyway, hope to read more coments on this before I finally decide and btw, thanks to all who have commented...

  7. I don't think tacking the bracket will help much. The bracket, under load, will attempt to twist around the axle. Usually the 3 bolt holes closest to the caliper are kept and the slot is made on the opposite side. Under the worst braking conditions, i highly doubt you could muster enough shear force for this to be an issue. The OEM brackets are cast iron
  8. Been there and done that! With success! :nice:

    Do the 87-88 T-Bird Turbo Coupe rear end swap!

    Auto trans 87-88 Tbird Turbo Coupes come with 3.73 gears and manual Turbo Coupes come with 3.55 gears. Cost is $125-$300 for the rear axle. Add another $100-$200 or so to complete the brake upgrade.

    I choose 3.55 since I do more highway driving. Both ratios have 10 5/16" disk brakes with vented rotors as standard equipment.

    It takes 2 guys the first day to get the old rear end out and the new one bolted in place. It takes 1 guy another whole day to do the brakes.

    You will need a several sets of fittings, I recommend that you get them from Matt90GT's website, Read Matt's instructions thoroughly, everything you need to know about the brakes is all there. You need to be patient and follow all the internal links, and there are many of them. You will need 2 fittings in the rear to adapt your old brake tubing to the TC disk brakes. The fittings go between the steel tube and the caliper brake hose. You will need another set of fittings to make a 2 port to 3 port adapter. To make life simpler, just buy the kits from Matt. You could piece them together, but it's not worth the time unless you work at an auto parts store with all the fittings ever made.

    You will need to drill the quad shock mounting holes 2” below the holes drilled for the Turbo Coupe mounting points. The bolts are metric, so don’t loose them or the nuts. A 15/32” drill should be about the right size unless you have access to metric sized drill bits. Going without quad shocks is not an option.
    When you install the axle assembly you will need to leave the bolts for the control arms only finger tight. Once the axle and all the control arms are in place, put jackstands under the rear axle and under the front A arms. Level the car as best you can while it is on the jackstands. Then and only then tighten down the control arm nuts and bolts to the factory specs. This assures that there is no preload to position the axle up or down, it is preloaded to normal driving height.

    You will need a proportioning valve, Summit has one for $40 + shipping.
    You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also has that, about $10.

    You will need a new master cylinder, see Matt's site and make you choice. I used a 94-95 Mustang master cylinder. Note that rebuilt 94-95 Mustang master cylinders do not come with a reservoir. That means a trip to the junkyard and some more money spent.

    Your brake pedal may be very hard and almost impossible to lock up the brakes. I had to replace the front calipers with 73 mm calipers from a 91 Lincoln Mark 7 to get the braking performance up to par.

    Bleeding the brakes will require 2 people and some coordinated effort. I don’t recommend using you wife or girlfriend to pump the pedal – they get offended when you yell at them. I used a homemade power brake bleeder constructed from a garden sprayer and some fittings from Home Depot. It cost about $25 and was worth every penny. See for details and pictures.

    See for help with the emergency brake. The red words link to some very useful photos on how to modify the handle. The stock setup tends to lock up and not release properly.
    All in all I have been very pleased with the results.

    Turbo Coupe axle swap parts list:
    87-88 T-Bird Turbo Coupe Rear axle
    94-95 Mustang Master Cylinder with reservoir
    Brake line Adapter fittings
    3 line to 2 line brake fitting kit
    Proportioning valve, Wildwood 260-8419 Summit or Jegs
    Kit to gut the stock proportioning valve Ford Racing M-2450-A Summit or Jegs
    Reuse stock brake booster – no changes needed with the parts in this list
    73 mm front calipers from a 91 Lincoln Mark 7 (two calipers) local auto parts store
    Emergency brake cable parts: Summit or Jegs or Late Model Restoration
    79-92 Mustangs use: M-2809-A* Parking Brake Cable (need 2)
    93 Mustangs: use 93 Cobra Ebrake cables.
    All years use: M-2810-A* Parking Brake Cable (short cable that attaches to the parking brake handle)

    I recommend that you use reman calipers and use the calipers from the Turbo Coupe axle for cores to return. The parking brake mechanism and the caliper slides tend to lockup and freeze

    Identifying a Turbo Coupe rear axle:
    1.) Measure the rotors - a TC disk brake uses 10 5/16" vented rotors.
    2.) Measure the length of the quad shock mount arm and compare it to the mount on your existing stock axle. The TC quad shock mount arm is about 8" long if I remember correctly.
    3.) Measure the distance between the axle flanges and compare it to stock. The TC rear axle assembly is 3/4" wider per side, or 1 1/2" wider for both sides.
    Fixing the added axle length problem:
    If the extra width is a problem for your wheel and tire combination, North Racecars makes some rather expensive brackets ($160 +) which allow you to use the stock axles. See
  9. Thanks J, for the response.

    I assume you mean that you've tack welded one of the rear caliper bracket choices that this thread is about. ( when you say: Been there and done that!) If so, would you give a brief description of how you approached the welding part?

    Thanks for the added option to a different approach to the 4-lug to 5-lug mod. I probably would have considered either of your detailed methods had I not already procured 90% of the parts to get it done with my OEM 8.8 and the donor parts from a 94GT. One compelling thing about your swap is the 3:55 gears OEM on the Turbo Coupe.

    Are your methods in the "STICKY THREAD" about 5-lug conversions? That would be a good place to plant that info...

    Anyway, I will be taking a look at the NRC Brackets and possibly not even bothering to tack-weld them. I thought tack welding the OEM Cut Brackets would safe some folks some money and be safer once tacked...
  10. No welding of anything on my brake system. The "Been there with success "was for the Turbo Coupe rear axle swap.
  11. Keep in mind that because the OEM brackets are cast iron, you may be doing more harm than good welding them to the steel axle tubes. Improperly welded cast iron is weak and now brittle cast iron.
  12. Thanks RacE!

    This is a bit of input that I was looking for. It seals my opinion of welding the OEM pieces. Conjoining this info with all the other inputs above, I have decided to just do the NRC pieces with NO welding - being that I can swing the extra cash-out. If I were on the budget AND certainly NOT racing the car, I would opt for the Cut OEM Bracket method.

    Thanks guys for all your input.