Finished prototype Mustang disc brake spindles

Discussion in 'Classic Mustang Specific Tech' started by degins, Jun 6, 2005.

  1. I am not the source for NPD. Their spindles are nearly identical to my spindles with two minor physical differences. The NPD spindles are expensive, $558 per set and dont include splash shields. Mine are $259 ($230 for forum members) for a complete set and they include splash shields. I'll look into the possibility of the GW kit fitting.

    Edbert or snakepilot,
    If you give me part numbers or model name of the GW set, it would be easier for me to be certain of the application that you are speaking of. Thanks.

  2. My first model knuckle and caliper bracket is an exact functional reproduction of the original Granada/Maverick type. As such this "spindle" will use granada outer tie rods. The model under development will use the same (or very similar) knuckle and a 68-73 type bracket. I say 68-73 type because there are, as you have noticed, at least 2 interchanges for the bracket during 70-73. They use the same knuckle and caliper. I have recently bought a bunch of sets of 70-73 so that I may figure out the exact difference.

    I think that I will use the same knuckle with both the Granada and the 70-73 type cliper brackets. I will lose interchangibility with original brackets, but I think this is more feasible than carrying two knuckles.

    Is there an Aussie equivalent for the Granada type brake system, perhaps from the Australian Falcon?
  3. I believe there is an Equivalent, from the XY Falcon of the same era (60s - 70s) I'm pretty sure it's either the exact same thing as late 60s Mustang suspension or it is interchangeable at least. I'm not too big of an expert on our classic cars though unfortunately, I like Mustangs. Also, there isn't many resources on Aussie Falcon suspension / steering swaps into Mustangs.

    Hang on, I think there is also a source of brakes from the XE/XF Falcon of the 80s too. I think the suspension and brakes may have stayed the same (basically) up until then.

    I'm not too sure though.

    Thanks for your reply to my questions!
  4. This is the brake kit I am interested in:

    Pro-Vintage disc brakes: The heart of our system is a well designed aluminum billet hub. The hub assembly provides the exact same offset as factory disc brake units. Wheel offsets with our negative Roll system are 3.75 backspace using a 14 inch wheel, 4.00 backspace for a 15 inch wheel, 4.5 backspace on a 16 inch wheel and 4.75 backspace for a 17 inch wheel.
    Pro-Vintage kits are offered in three different diameters, 11.75, 12.00, and 13.00 inch.
    We also incorporate aluminum hats which attach to the rotors for two reasons:
    First, we want to further reduce heat going into the hub and second, we can index the hat on the hub, rather than on the bolts. This combination provides longevity for the hub and bearing assembly, plus reduces overall weight. The calipers are Wilwood Super Lite II's 4 piston calipers. We chose Super Lites for 2 reasons, piston diameter and overall physical dimensions of the caliper.

    Brake calipers are bolted into position with special steel brackets. Master cylinder, adjustable proportioning valve and braided steel lines are also included.

    Spindles needed for this kit are the large bearing spindles. We use the large bearing spindles off of 1969-73 Mustangs.

    1967-1968 Mustang with spindle assembled 13.00 rotor PVM-6813
  5. Degins I don't know if this will help, but here are some pics of a 71 disc knuckle. This LOOKS just like (that is the caliper bracket look just like) the 70-73 that NPD advertise. Whether NPD pic is correct or not is another question.

    I don't know if that helps or confuses the issue.

    I hope you can end up with a strong Mustang spindle, that I (and probably many others) might be able to use with a brake kit. If you use the same spindle as the one you have, and lose compatability with original brackets, this means most likely that kits won't fit either.

  6. Thanks,
    I have specimens of 70 and 71 disc brake knuckles. My first exam indicates that they are identical. I'd guess the interchange difference must be in the bracket. I'll be taking a closer look after my first production batch of the granada spindles arrive next week. I'll consider making an interchangable 70-73 knuckle and bracket(s) if the market warrants it.
  7. So do you mean that the calipers themselves probably mount to the brackets differently and the bracket to spindle mount is the same?
  8. Reading through NPD's catalogue again, and 68 - 73 use the same single piston caliper.

    Apart from overall geometry changes, there is only the tie-rod taper and the spindle size, which are both known to have increased in 70, but remained the same from then right? There is also the ball-joints, did the taper for those change maybe?

    Hmm, interesting indeed. There is the dicrepancy on Baer offering kits for 70 and 71-73 seperately. Balljoint taper shouldn't effect brake kits though. Perhaps there was a performance caliper option or something in 71-73?
  9. There are two types of disc brake knuckles during the 68-73 period. The small pin variety of 68-69, and the larger pin 70-73 one with a slightly larger tie rod mounting hole. The knuckles are otherwise identical (same geometry, same mounting). I suspect that the interchange difference between 70 and 71-73 spindle assemblies is subtle. There was only one caliper used during the 68-73 period on main production Mustangs.

    I'll scrape off the ton of grease and rust from the examples that I have, make some measurements, and let you know.

  10. i may be wrong but i think that one of those kits is for drum spindles and the other is for disk spindles
  11. Bnickel I thought someone was going to say that, but sadly no, they have the follow segregation in kits

    70 with disc
    70-73 with drums
    71-73 with disc
  12. I think (hope) you're going to find you're correct about the subtle changes, I was reading an article last night, saved the link and they say from 68 up they used the single piston floating caliper, with the most significant change to this setup in 1970 with a larger spindle. (I'm not sure if they meant the knuckle or just the spindle bit, but either way they would be correct.)

    I hope they (70-73) are the same, that would simplify things, but I'm wondering why no-one's yet to have picked it up that they are the same. Maybe the Mustang body type was used as a clue, 71-73 were very much like our 70s Falcons, and different from the 70 model.
  13. Hello Degins. I'm resurecting this thread to see how you're coming along with the spindle development.

    You mentioned that you were planning to produce a '70 spindle in the future, possibly followed by a drop spindle. Rather than produce a drop spindle, which may have a limited market, how about producing a '70 style spindle with a 1" shorter steering arm for use with all the R&P kits whose turn radius is now wider than stock? Also, what would it take to get you to make a production run of "custom specified" spindles with both a shortened steering arm and a raised pin instead of a dropped neck. In other words, the overall height remains stock, but the spindle (pin) and brake mounting points move up relative to the ball joint mounts? This will maintain the geometry relative to the uca and lca, but will enable the spindle to fit inside a 17" wheel without using spacers.
  14. The project has come along quite well, thanks. I have just received my second shipment of spindles and slotted rotors. Sales have been very good and I have had no customer complaints. I will receive my final (hopefully) 65-66 geometry specific prototype tomorrow. Production is scheduled for next week. I am also modeling original 70-73 style disc brake spindles, caliper brackets, shields, slotted rotors, hoses, and calipers. I am seeking to constantly improve the quality and content of the kit. I will soon be including, in every kit, new corossion protection coated calipers with stainless steel pistons, an adjustable pushrod, aplication specific outer tie rods that don't require adapters, and brake hose to chassis brackets. I'm also working on year specific hard lines and power brake pedal and booster conversions.

    The problem with producing specialty spindles is that I think that the market is very limited. It cost me several thousand $, a lot of work, and a lot of time to model a new spindle and produce the tooling. the production run would need be fairly large.

    The R&P special spindle has come up several times and I asked the forum community to show its interest by suggesting specific (3D) geometry for the steering arm, but got no response. I would need to have this issued well defined before proceeding. I'm afraid that a dropped spindle is a low priority right now.

    I appeciate your interest and input.
  15. Degins, i think a spindle with a repositioned pin that would lower the car would be a very good seller. by raising the the pin about 1-2" (i forget what the optimal distance was) in the casting but basically leaving the rest of the geometry alone would give a much better scrub characteristic as well as lowering the car at the same time while keeping the rest of the geometry essentially stock and workable. that also accomplishes better centering the wheel between the upper and lower control arms which would allow wider wheels to be used and that is where the scrub radius comes in. it would be a compromise of course as anything suspension related always is but there is not another manufacturer that makes anything like it the only option is to order custom Coleman spindles or the like.

    if you could produce a spindle like that with the raised pin you would basically have the market cornered. i believe there is a huge market for it for the performance guys as the stock spindle is basically the only major factor in getting the early cars to really handle like modern cars. it would be like Bell Tech was in the 80's when they were the only company that made lowering spindles for chevy trucks, the entire market for lowered sport trucks grew up around Bell Tech spindles. i honestly believe that there is a large untapped market for lowering spindles for early mustangs. everything else about the mustang suspension can be optimized with something IE: rack and pinion conversions, coil over kits, upper and lower control arms with better geometry and stronger, strut rods, altered suspension pickup points etc. everything is covered except the spindle. the aftermarket pretty much even has the rear suspension stuff figured out with bolt in 3 and 4 link systems, panhard bars, watts links etc. but again the limiting factor is the front spindles.

    i think you should contact companies like TCP, Global west, Air Ride Tech, etc and see if they think there is a market for a good drop spindle. it's very likely that if you were to produce one that these companies would either offer as part of their front suspension kits, offer it seperately or even it just put a link to it on their website possibly all of the above. i truly think it would be worth your time to investigate it.

    as for the altered tie rod placement for the rack and pinion kits i can give you a rough idea of where it needs to be located. basically it needs to be relocated about 1.5" toward the pin and about 1" outboard from where it is now. you could most likely just add another hole for the altered placement to the existing spindle though a little extra meat around the boss wouldn't hurt. if you wanted you could just have one casting to cover to stock and the altered location and just not machine the altered location for the stock replacement version. even on the altered version you could still have the boss for the stock position or you could cut it off completely for a cleaner looking part.
  16. The production Granada spindle steering arm gets wider at the tie rod hole. If that width was extended an inch toward the pin you would have the option of relocating the tie rod. If you are not too far along in developement of the 70 and up, please consider some extra meat. I think the RP industry would jump on it.
  17. i have seen the mod done to production granada spindles, there is enough meat there, but a little extra would be nice to support the tie rod. used to have the mod outlined on there website but they took it down for some reason. I'm sure Randall himself would have the specs of where the tie-rod needs to be relocated to.
  18. If you machine your own hole, you can use a size that cirlce trackers use. Bumpsteer kits are 1/3 the price from race car suppliers.
  19. bnickel,
    I suppose that a drop spindle application based on 70-73 type would not use the original caliper. Would it then be better to base the spindle on disc or drum design? I know there are caliper brackets available for both the 70 disc or drum spindle that use later model calipers and larger rotors. Would these brackets clear the tie rod castle nut if the tie rod mount hole is repositioned as you propose for R&P? Thanks for your constructive response.
  20. as for the brackets clearing the castle nuts on a repositioned tie-rod application i don't think there would be a problem possibly have to notch the bracket but i doubt it, it really isn't moved that far forward and any interference would be minimal.

    i suppose on the drop spindle that it may be beneficial to use a drum spindle. as you say the stock brake bracket would be pretty useless with a relocated pin. although it might be possible to use a modified caliper bracket with a spacer at the upper mount location to push the caliper outwards thereby allowing it work the new pin location. i guess more research is in order. the guys at know all the specifics on the drop spindle needs better than i. maybe i could start a new topic on the subject and you could join in and we couild get a better idea on the brake part of it. i've always planned on using non-stock brakes anyway so i guess the question of mounting the stock units never crossed my mind.