Mustang Drop Spindles

Discussion in 'Classic Mustang Specific Tech' started by degins, Nov 28, 2006.

  1. Some of you have participated in the earlier thread discussing a drop spindle for our Mustangs.

    I have bought a couple of pair of D0 drum spindles and am ready to start the evaluation and design. I want some input on a few issues. For that person(s) who will inevitably post about your distain for the fact that I need to ask these things, I never claimed a performance inclination, just the ability to make this project happen, so don't bother.

    There are two areas that I want clarified.

    1. How much drop is needed (or wanted)? How much is too much (will create interference at the lower control arm)?

    2. I intend to preform a second tie rod mounting point on the steering arm at a point about 1.5" up the steering arm for R&P applications. How thick should the mount be (In the direction of the tapered hole)? What ball joint stud taper should be standard on this second mount (top and bottom diameter and depth of the hole)? Are there going to be tie rods available that are correct for the second mount? What size threads are used on outer tie rods for the various R&P systems?

    The questions in 2. above is predicated on the assumption that the available rack systems come with outer tie rods propper for the different year model Mustangs. Are these tie rods different than the original ones? If so, then the tie rod issue is going to be a mess.
  2. I can not answer your question but have one of my own, My ex father in law said that the Bill Stroppe prepared drag Shelby's solved the steering problem in the mustangs by lengthening the spindle's, and relocating the control arms.
    He promised some tech on this but, he could not recall if it was just the standard Shelby drop in conjunction with the lengthened spindles.
    I am hoping someone can chime in, if there would be any advantage to the lengthened spindles Maybe you could produce them also, make a mint and send me 1\2 for the suggestion:D .
  3. 1: i think most of have agreed that a 1" drop would be good but some want a 2" drop and some don't. i think a 1" drop will help the geometry issues immensely.

    2": all the aftermarket racks have provisions for any of the early tie-rods and even granada tie-rods on most if not all of them, you don't have to use a specific spindle on any of them so you're good to go there with whichever one you decide, but i would suggest the beefier 70-up tie-rod taper. of course that means i'll have to change the outers on my 69 to 70 units but i'm cool with that. :D i think the thickness of the added tie-rod mount should be the same as the original location mount but you can probably go a bit thicker there but probably not too much, maybe 1/8" or slightly more. any thicker than that and i think you'll run out of room to put a cotter key in the castle nut but as long as the cotter key can be used still go as thick as you need to, i do seem to remember the steering arm getting thicker closer in to the spindle pin, is that what you're running into?
  4. 1.5" drop? & picture worth 1k words

    Thanks - eagerly awaiting this project. I think many of the guys on the Pro-Touring forums especially and here in general will be as well, as they are dropping their cars and putting on large wheels and wide tires - a drop spindle will get the lip of a 17" wheel over the UCA.

    1. What about a 1.5"? I don't think any of the 1" guys will mind, and you will rope in some of the guys looking for 2" - better market appeal, even if it is mainly a psychological thing to show you are acommodating everyone. A 1.5" drop may also clear different types of UCAs farther in - if you raise the wheel up, it will help it clear the various designs of UCAs a little better, and therefore let people use bigger front tires and wheels. BIG plus for the Pro Touring guys. Should not be a problem down below at the tie rod mount point, there's a lot of room there for more tire and wheel.

    2. Not sure about the first question. I am sure the guys who are NOT using R&P will want to see thick metal around that second tie rod hole - psychological fear of breakage thing here. Second - not sure, same as stock spindle, I assume, since everything else is made for that - bigger market.

    My Steeroids rack came with proper length tie rods, and the kit was a '67-70 kit IIRC. The adjusters are pretty much bottomed out, as you can see, and I believe they will have to reach farther to get to the 1.5" farther in mounting point. So at least in my case, I can just thread them out a bit, no problem.




  5. i'd be cool with a 1.5" drop.
  6. When and how much?

    What does the production timeline look like and what is the target price?
  7. I second snakepilot's post!
  8. +1 on a 1" drop how much do you figure a pair would run if u had enough interest?
  9. I'd figure 4 months and $300/set.
  10. sounds great too me. keep us posted please.
  11. I would buy some as well.
  12. I might be able to get ball joint taper and such for each year stang tie rod if I can find the suspension parts book at work. It should have the taper degree, diameter of hole plus thread diameter, and thickness of the hole... I'll try and get it for you wed.
  13. the second hole (the one closer to the wheel) will have to have more material around it than the original hole if you want to maintain the strength of the steering arm. the closer you place the tie rod to the center of rotation, the more force will be required to generate the same torque on the spindle. If you know the properties of the material you're using, it wouldn't be too difficult to calculate the area needed.

    Personally, i'd just stick with the stock position for the hole. A lot of people end up running bump steer correction kits , which move the tie rods closer to the wheel.
  14. i think the idea here is to have the option of using one casting for 2 different spindles. if he drills/machines the relocated mount out, the original mounting boss would most likely need to be cut off. on the regular location the relocated mount hole would not be machined.
  15. My understanding is that the 71-73 tie rods are bigger and beefier - the same ones used on the 69-70 boss. I would go with those.

    I second 1.5" + of drop.

    Also, position of the inner hole is somewhat crucial. Send me a PM you still have time to select where it will be and i will scour for someone who can give you a good answer.

  16. shagg, you are semi-correct that the 71-73 tie rods are the same as what was used on the 69 Boss but the 70 Boss used the same tie rod as all other 70 models, even the 6 bangers and they are the same as the 71-73 units as well.
  17. Spendles

    For myself a 1" drop is preferred. Question 2, If both holes are machined I would include a little extra metal around the non stock hole. Maybe a tapered bolt to use when using the stock location. Can't collapse if there is a tapered bolt in there.
    I will buy a set if, 1 drop is not to severe. 2.they have relocated rack steering tie rod hole.
  18. I figure a drop can be done with springs no problem. Getting a 9"-10" wide wheel on will require a drop spindle, and thats where this can shine.
  19. I definately agree that puting extra material around the second hole would be a good idea. As for how much to drop it, I think 1 inch is good and 2 inches is too much. Either way, a 1 or 1.5 inch drop would work for me and everyone else I know. The more wheel/tire combos you open up with your product, the more marketable it will be. Either way, as long as its between 1-1.5 inches I'm in for 2 pairs =-)