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  1. #1

    Default Wheel Alignment Spec Question

    Ok, this may be a silly question.

    On my PC I upgraded all the front end suspension to 87-93 parts - steering rack, knuckle, brakes, tie rods, etc etc. I have the car in the shop this morning for a wheel alignment. I let them know about the upgrade parts, but they were asking what specs should they use - 79 specs or 87-93 specs? I told them to use 87 specs... but I'm not sure what the real difference would be. Is there a significant difference?

  2. #2

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    Update. Got the car back late yesterday afternoon. The shop said the alignment went good, no problems. I took the tires off today to have a look. Turn the wheels all the way to the right and the driver side strut rubs up the K-member. Turn the wheels all the way to left and the passenger side strut rubs up against the K-member. I'm thinking that can't be good.... back to the shop on Monday.

  3. #3
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    Did you use the lower control arms from the 87-93? They are longer than your originals. The only setting that needs to be set right would be the camber. Caster isn't that important, and neither is toe in. The camber will cause tire wear more than toe in. Caster helps with steering returning to center on it's own, when coming out of a turn. Most people would give as much caster as it can take.

    So if you used everything from the donor car, then I would say yes you should go with the newer specs. Tire wear will tell you if it is right. The longer lower control arms will cure the strut rub problem, if you are still using the 79 arms.

  4. #4

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    I am thinking I just don't understand the wording of the post above. I completely agree that they should just pull the caster back as far as it will go. Don't need a machine for that. Just pull it back until it won't pull any more and that will have to work. There is nowhere near enough caster even available in the OEM setup so you can't go wrong. There was another sentence that I think I just don't get what he means. Toe adjustment would be absolutely without question need to be set. If it is out even a little, the outside (and possibly inside) edges of the tires will absolutely be obliterated in 150 miles. It causes massive cupping or feathering. You will feel it in the steering wheel but by then, it is too late. And fixing the alignment won't cause the tires to go back. The damage is done. The camber is important also because if it is out it is possible you wouldn't even notice until you had tire failure. The inside edge of the tires could wear clean through while the outside edge looks completely brand new with no wear. Or the opposite is true depending on which way it is out. It would steer straight and drive fine until the shoulder of the tire worn.
    Last edited by homer302; 11-11-2016 at 07:19 PM.
    Liberty once lost is lost forever.

    John Adams
    July 7, 1775

  5. #5

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    So back to your question. I have the entire crossmember and brakes from a 1990 on my 1984. The control arms are the same from 1979-1993 so again I am confused by the above post. LMR lists one control arm for the whole generation. I changed the whole thing because it is faster then blowing the '87 crossmember all apart, taking the old crossmember apart and then removing it and then asssembling it all again. I just dropped the struts, crossmember, steering rack, tie rod ends and all and rolled it under my '84 and bolted it all back up all assembled. It fit fine and I have no rubbing. Can you post where and what exactly is rubbing?
    Liberty once lost is lost forever.

    John Adams
    July 7, 1775

  6. #6
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    Of course the toe in needs set as well. You can't have it too far in or out. My point was, if the control arms are not the same length, then the camber is going to be the biggest problem to deal with. It is the most important item to contend with. The spindles are different for each of the years listed. I do believe they are different lengths. It's been a long time since I did that change myself. Just because an aftermarket sells a part and list it for all models, doesn't mean the stock ones are all the same.

    If the strut is rubbing on the K member, that help's proves my point of a longer control arm in the newer model.

  7. #7

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    Quote Originally Posted by dynodon64 View Post
    Of course the toe in needs set as well. You can't have it too far in or out. My point was, if the control arms are not the same length, then the camber is going to be the biggest problem to deal with. It is the most important item to contend with. The spindles are different for each of the years listed. I do believe they are different lengths. It's been a long time since I did that change myself. Just because an aftermarket sells a part and list it for all models, doesn't mean the stock ones are all the same.

    If the strut is rubbing on the K member, that help's proves my point of a longer control arm in the newer model.
    You absolutely CAN have the toe too far in or out. The caster you can't go too far with. If the toe is out either way the tires will be recycle material in 150 miles. All 1979-1993 control arms are the same length, regardless of the model or engine. The spindles are not the same, that is true. I am not sure what you mean by the length but at any rate they are not the same part for sure.
    Liberty once lost is lost forever.

    John Adams
    July 7, 1775

  8. #8

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    I would hope nobody would purposefully set anybody's caster negative, but too much (there's really no such thing. ANY negative caster is too much, lol) negative caster would bring the spindle tops and strut bodies closer to the k-member at full lock turns. The left strut when turning right, and vice versa. Positive caster also helps with no-hands straight ahead and with directional stability.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  9. #9

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    Quote Originally Posted by Walking-Tall View Post
    I would hope nobody would purposefully set anybody's caster negative, but too much (there's really no such thing. ANY negative caster is too much, lol) negative caster would bring the spindle tops and strut bodies closer to the k-member at full lock turns. The left strut when turning right, and vice versa. Positive caster also helps with no-hands straight ahead and with directional stability.
    Okay, hahaha. So I guess technically you CAN set caster too far but maybe I presumed too much, LOL. It can't go too far towards the REAR of the car. No harm in clarifying that so thanks. You never know what kid is working on your car so if you tell him he can't go too far who knows what he might do! You are right!
    Liberty once lost is lost forever.

    John Adams
    July 7, 1775

  10. #10

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    Quote Originally Posted by homer302 View Post
    You absolutely CAN have the toe too far in or out. The caster you can't go too far with. If the toe is out either way the tires will be recycle material in 150 miles. All 1979-1993 control arms are the same length, regardless of the model or engine. The spindles are not the same, that is true. I am not sure what you mean by the length but at any rate they are not the same part for sure.
    What you said about toe can't be mentioned too many times. These cars especially can be quite "darty" if not right. When mine was toeing a wee smidge out, each and every dip and such in the road yanked the car all over the place.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  11. #11
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    Quote Originally Posted by homer302 View Post
    You absolutely CAN have the toe too far in or out. The caster you can't go too far with. If the toe is out either way the tires will be recycle material in 150 miles. All 1979-1993 control arms are the same length, regardless of the model or engine. The spindles are not the same, that is true. I am not sure what you mean by the length but at any rate they are not the same part for sure.
    That's was my statement says. You don't want the toe too far out or in, not that it can't be too far out or in. The OP said the struts were contacting the frame or K member. It's been a long time since I did one, but the K members might be wider on the newer model. Something is setting the strut closer to the frame, so it has to be one of the parts replaced that is causing the problem. It it didn't rub before and does now, do the math.

  12. #12

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    Quote Originally Posted by dynodon64 View Post
    That's was my statement says. You don't want the toe too far out or in, not that it can't be too far out or in. The OP said the struts were contacting the frame or K member. It's been a long time since I did one, but the K members might be wider on the newer model. Something is setting the strut closer to the frame, so it has to be one of the parts replaced that is causing the problem. It it didn't rub before and does now, do the math.
    Okay, glad to hear. If you go back and read your post I quoted I think you made a typo (no, I KNOW you made a typo) and said you can't have the toe too far out. No worries. We are in agreement then!
    Liberty once lost is lost forever.

    John Adams
    July 7, 1775

  13. #13

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    Thanks everyone for the posts. To clarify, I do have the 87 spindles on and not the 79. I also put on after market caster camber plates, but still using the conventional coil/spring set up (ie: not coil overs). What I don't understand is why the shop didn't test for clearances. Either there is something not right in my parts/set up or they didn't do a good job. Either way, I'll be having the conversation on Monday with them. They shouldn't have let the car go like that. Thanks again, there's lots here for me to mull over.

  14. #14
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    What are all the parts you installed from the 87-93? This will help us figure out what is needed to correct your problem.

  15. #15

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    Quote Originally Posted by dynodon64 View Post
    What are all the parts you installed from the 87-93? This will help us figure out what is needed to correct your problem.
    Spindle, brakes, steering rack with tie rods, struts .. pretty much everything.

  16. #16
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    Did you get the lower control arms from the 87? From my searching, I found different part numbers for 79-86 and 87-93. If you have them or access to them, measure the length of both years. You may find that the 87's are longer. Years ago when I made that upgrade, I used the control arms from the newer car.

  17. #17

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    Quote Originally Posted by dynodon64 View Post
    Did you get the lower control arms from the 87? From my searching, I found different part numbers for 79-86 and 87-93. If you have them or access to them, measure the length of both years. You may find that the 87's are longer. Years ago when I made that upgrade, I used the control arms from the newer car.
    I got new a-arms from LMR with the pre-installed ball joints. They're listed as 79-93 years. I don't have the old ones anymore to compare, but I don't remember much difference with them before I sent them for scrap. Maybe I need to find scrap 87 arms to compare?? Another strange thing I just discovered is the caster plates on the passenger side are set way in-ward toward the engine. So much so, that the other end of the top plate running across the top of the hole of the shock tower is right at the lip of the hole. I'm not liking that set up either.

  18. #18

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    Quote Originally Posted by homer302 View Post
    So back to your question. I have the entire crossmember and brakes from a 1990 on my 1984. The control arms are the same from 1979-1993 so again I am confused by the above post. LMR lists one control arm for the whole generation. I changed the whole thing because it is faster then blowing the '87 crossmember all apart, taking the old crossmember apart and then removing it and then asssembling it all again. I just dropped the struts, crossmember, steering rack, tie rod ends and all and rolled it under my '84 and bolted it all back up all assembled. It fit fine and I have no rubbing. Can you post where and what exactly is rubbing?
    Just to clarify, I am still using the original K-member. I didn't see any where that the 87-93 K-member would be required for the upgrade. The upgrade was done basically for the bigger brakes. When I did my research on the brake upgrade, I did not see anywhere that the k-member would need to be upgraded.

  19. #19
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    I'm sure there are differences in K members through the years. I don't think you need to swap it over. What we know from what your saying is, in order for the shop to get it aligned, they had to pull the right side in to the max to get the camber set. That tells me that the newer spindle is is pointing down too much. A longer lower control arm would help here. That would lift the end of the spindle up.

    Now there is two things that come to mind that might fix it.

    1st one, remove the bottom bolt holding the strut to the spindle and put in a smaller diameter bolt, that will allow the spindle to lift up. Now the best thing to do is make a bushing to fit in the spindle hole, but drill the hole for the new bolt so it is off set close to the edge in the bushing.

    2nd one, see if the K member can be shifted more to right side by loosening the six bolts that hold it in. That will help the right side but not the left. May help to split the difference. The K member can be moved around with this method. It may need some of the holes elongated to get the movement you need.

    But in the end, it sounds like you need to move the lower control arms out to get the spindles to point up more to get the negative camber you need.

  20. #20

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    Well, called the shop back today. They said they had to use chassis specs - so 79 specs, not 87 specs - for the wheel alignment. Not even sure what that means, or even matters with the problem. The CC plates I'm using are the SVE brand from LMR .. they had good reviews. I wonder if a better set like MM would give better results. I know my tires were rubbing the back of the K-member as well at the extremes, even with 1/4" spacers. I was going to put on rack limiters for this problem, maybe they could help with the strut clearance as well. Is it common to have tire rubbing issues with only 8'' rims, even with spacers?

  21. #21

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    The problem with most alignment shops are, they normally only know how to setup stock setups. The Stock Mustang suspension in most cases doesn't need to have the Camber and Castor set, because the factory sets it with a pin and its usually good for the life of the car, but when you add adjustable CC Plates and other parts to the suspension, then the Alignment Tech needs to actually adjust it, and in a lot of cases its done wrong.
    You might try doing your own alignment, MM sells a simple tool to adjust the Castor and camber, you can then do the toe in using the String method, or get some Toe in Plates and tape measures.
    You can then go to the alignment shop to fine tune it, if you feel its not right.

  22. #22
    FEP Super Member xctasy's Avatar
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    The latter K- member has issues with early Foxes when setting camber.....

    Fox Suspension Struts...you'll like this

    http://vb.foureyedpride.com/showthre...Specifications

    http://vb.foureyedpride.com/showthre...ut-Differences

    Replacement later struts have a bolt spacing change as well. The holes are further apart on '87+ spindles.
    The upper strut mount bolt spacing changed in 1990 ,you have to elongate the top hole on each strut to make them fit.

    http://vb.foureyedpride.com/showthre...e-my-strut-out

    The drillings changed at various times, and the widht of the K member after 1989.

    So some parts don't work together without work.

    http://vb.foureyedpride.com/showthre...fairmont-build

    Quote Originally Posted by Mike1157 View Post
    If you want to put anything wider than a 17 x 7 up front, You are going to push the tire out farther than you want it to go by using the late model K member. The front LCA's are significantly longer than stock Fairmont fender will accommodate.
    I have the stock 78 K member, w/ a 17 x 8 up front and by the time it was lowered to where I wanted it to ride at, getting the front end/tires back to alignment spec required a set of CC plates. Those plates barely have any adjustment left.
    The reason I say 17 x 7 instead of 17 x 8's is that you are going to lose an additional .750 clearance by using the 90 Mustang front end/LCA. It is that much longer than the stock Fairmont arm.



    Quote Originally Posted by Mike1157 View Post
    Dug these up from when I first attempted fitment on a set of 17 x 9's


    Looks Ok until you attempt to steer it.



    This is with stock LCA's and 94 spindles. I ended up getting everything to work w/ 17 x 8's

  23. #23

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    Quote Originally Posted by Chortdakooba View Post
    Well, called the shop back today. They said they had to use chassis specs - so 79 specs, not 87 specs - for the wheel alignment. Not even sure what that means, or even matters with the problem. The CC plates I'm using are the SVE brand from LMR .. they had good reviews. I wonder if a better set like MM would give better results. I know my tires were rubbing the back of the K-member as well at the extremes, even with 1/4" spacers. I was going to put on rack limiters for this problem, maybe they could help with the strut clearance as well. Is it common to have tire rubbing issues with only 8'' rims, even with spacers?
    Had to... It means that they're inside-the-box, liability-fear-driven meatheads. Stupid is the new smart. It absolutely matters for the problem you have now, that they, in their infinite wisdom, and decisions made for you, have created. Tell them about some more potentially damaging liabilities, such as the steering jamming and wedged stuck to one side or the other at a time while at full turn to avoid an accident, etc. If a sane and knowledgeable person visits an alignment shop for an alignment with intelligent specifications they want for their automobile, the alignment shop should be setting YOUR specifications if they want YOUR money. You're also in Canada, and I know a thing or three about dealing with nonsense like this - call the Ministry of Transportation and explain what's happened.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  24. #24

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    Thanks everyone for the inputs. Ectasy those threads offered good information. WT, not sure if I'll go as far as report to Min of Transport. Part of it is my error in taking it to a chain repair shop (OK Tire), that's geared towards new vehicles and stock specs, as Fastlane mentioned. I should have looked more at taking it to a speed shop that has more experience in after market parts and old cars. That still may happen, but I may also entertain the MM tool and look at doing it myself.
    Even so, as I understand it from the information I got, to create the clearance of the strut from the k-member when the wheel is turned, means moving the CC plates out towards the fenders (ie: creating positive camber). If the shop used Ford specs, which was barely any neg camber, then I'm hooped. To get the neg camber specs as outlined by MM (which seem more reasonable), means moving the plates even more in towards the engine, which will in effect increase the rubbing problem I have now. The passenger side plate is about as far in towards the engine as it can go. I did not get a spec sheet from the shop. I'll phone back tomorrow and see if they can provide one.

  25. #25

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    From my experience for the most part for the last decade or so, doing it yourself is a very good option.

    We have no idea unless and until you get that spec sheet, but it sounds like they set too much something, and/or things are not equalized side to side. Following whatever '79 specs, no doubt they did not set much positive caster, or negative camber, and as I stated earlier, odds are too much negative caster would give the result you've got. Tilting the struts back, setting more positive caster, should definitely get the struts away from the k-member upon full lock turns anyways... good luck with it.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

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