1966 Alignment Questions

Discussion in 'Classic Mustang Specific Tech' started by bizkit1976, May 7, 2013.


  1. bizkit1976

    bizkit1976 New Member

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    Hello All...

    I have a 1966 coupe, 289, c4 transmission. I just got finished with a front end suspension rebuild. I replaced both upper and lower control arms, all new bushings, rebuilt the control valve, new idler arm, tie rods, and did the Shelby drop while I was in there. That is the history....

    I have now been trying to get her aligned properly. I took her to the go to shop in my area and they cannot get the caster right on her. The best they have it is +2.6 on the driver side but -1.0 on the passenger side. This is causing the car to pull to the right. My other numbers seem to be good but this caster is driving me crazy. I would love to hear some recommendations from you all. From what I have read, adjustable strut rods might be able to help me get these caster numbers a little closer together.

    Thanks in advance for any guidance out there....
    #1
  2. dennis112

    dennis112 Active Member

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    Caster should be positive and the same (or within 1/2 degree with the lesser being on the LH side to account for the road crown.) If the shop could get the passenger's side to be just as positive as the LH, you would be golden and track nice without pulling anymore. Also camber and toe-in should be in the proper range too. Most shops don't like spending hours aligning a gen 1 Mustang due to all the shim work. For that reason I just recently purchased a simple caster/camber gauge and learned the ins and outs of Mustang alignments. Using the gauge was easy. Messing with the shims was the time consuming part.

    I recently installed a set of adjustable strut rods on my 65 and the difference at high speed is phenomenal. I drag race my Stang and with 3.5 degrees positive caster the car drove like it was on rails at 128mph. Even though the adjustable strut rods can accomplish the caster adjustment by themselves, it is still best to have the upper control arms shimmed properly for max caster before adjusting the rods. The rods pull the lower control arm more forward while increasing caster and this can be noticeable.

    I detailed my experiences installing the Calvert adjustable strut rods and doing my first front end alignment in the following link in posts #242 and #246:

    http://www.fordmuscleforums.com/makin-progress/500588-65-mustang-gt-7.html

    Before the installation driving over 100mph was a somewhat white knuckled experience with the car drifting from side to side. With the struts and more caster, the car now goes straight down the track with minimal to no correction.

    Good Luck!
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  3. bizkit1976

    bizkit1976 New Member

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    Thanks for the reply Dennis. I understand everything you said. The thing that is killing me is why could they get positive caster on the driver side but not on the passenger? I talked to the mechanic and he said that he Putin as many shims as he felt comfortable doing. I am assuming that there is a limit?

    On the Caster/camber gauge, I am almost there. It will be a Pita but at this point, I just want it done. The good thing is that I brought my car there twice and they didn't charge me for either. The first trip was a disaster, they just looked at it and told me to get it right. ( I jacked up the control valve adjustment and the steering wheel would turn by itself on startup and installed a tie rod backwards). They felt bad that they couldn't get it to the spec sheet I brought with me and didn't charge me again. I'd really like to get my car right so I could at least bring it back so they can do the job.

    I've read about multiple things I can do to increase caster but I am not sure if ther is an under lying reason on why the two sides would be so far off?

    Do you think the adjustable strut rods can get me there?

    Thanks again....
    #3
  4. dennis112

    dennis112 Active Member

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    Was the Shelby drop done correctly? The holes are not only dropped, they are also offset. Done poorly it would definitely affect caster if the holes were not drilled properly and equally on both sides of the car. Could the car be aligned before the drop?

    The template in the back of a Tony Branda Shelby parts catalog are the correct dimensions and of actual size. Some internet templates do not print properly so the dimensions should be double checked before drilling.

    The only reason that I think one would not be able to put more shims on is that there is no threads left on the shaft bolts to hold more? I am new to Mustang alignments so that is only my opinion based upon observation. Perhaps there is something that I don't know about it-maybe the shop manual says something. I added an additional 1/8 shim to the front of both shafts from the previous alignment done at the local garage. There are definitely more shims on the front of both control arms than the rear--2 on the rear and 5-6 on the front.

    The whole idea with the shims and caster is to push the upper ball joint behind the front. There could be damage on the RH side, but I really cannot tell you why they are having issues. That would take a closeup inspection. Could be the tower or even the strut rod or frame bracket is damaged. It is also possible that the upper control arm bushings were replaced and the shaft was not centered or was shifted more toward the rear. Some people induce more caster by removing the upper control arm and pressing out the shaft bolts. Then rotate the shaft 1 turn in the direction that moves the ball joint/control arm more rearward and then reinstall. I would try that first if I didn't suspect anything else.

    Installing the adjustable strut rods with the suspension messed up from side to side would only be a band-aid, although it might work in a pinch. The rods would certainly be different lengths. A side note is that the 67 and up Mustangs do not use shims, only the factory adjustable strut rods. Obviously its your call on what you do. I do know that I wouldn't be pleased with 3.6 degrees difference in caster from side to side and would do whatever I could to correct that, with the obvious things tried first.

    A good cheap set of adjustable strut rods that are easy to install can be ordered from Glenn here: http://www.rosehillperformanceparts.com/

    He was out of stock when I wanted to order them a couple of weeks ago, but he should have them shortly. Contact Glenn and he will gladly give you an expected completion date. He is a good guy too.

    Recheck that Shelby drop.
    #4
  5. mtaqua

    mtaqua Member

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    Dennis has covered where the problems may be, I'll give you my experience with alignments. I concur with Dennis on the adjustable strut rods. I run 6 degrees for the same reasons he stated. I can drive hands off, it has no choice but to track straight. High speed, low speed, what ever it wants to go straight. It is hard to park, but I've also got a spool I am fighting. I am sure my tire wear is increased, but nothing like the drag radials on the back. The alignment process is rather easy. 4 jack stands, two pieces of conduit and some string. Make parallel lines with the string, conduit and jack stands measuring from the wheel centers. Then set the caster/camber gauge up on the wheel and follow the directions. Toe is measured with a measuring tape. I will say it sucks doing it with shims. I have probably over 20,000 dollars easy in my 66 coupe, the single best upgrade I did was the Chassis Engineering UCAs. They have jam nuts that you can get to easily for alignments instead of shims. It makes the process extremely easy. With those and the adjustable strut rods I can align my car in about 30 minutes. It takes me longer to get the jack stands, poles, and strings set up than it does to actually align the car. If you still have the original holes and are thinking about changing UCAs, Chassis Engineering has UCAs with the drop in them.
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  6. bizkit1976

    bizkit1976 New Member

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    Great info, I really appreciate it. We went over the measurements for the shelby drop numerous times before we drilled so I am confident that we got that right. (down an inch and back 1/8th if memory serves me correctly?) I am going to put her up on Jack stands this weekend and look over the frame rails really well. In the mean time, I am going to order some adjustable struts. From what you guys are saying, I really can't go wrong with them.

    As far as the UCAs mtaqua mentioned, I am going to look at those now. I just bought new upper and lowers so that might be a hard sell to accountant but we shall see :) I will keep you posted on what I find.

    mtaqua: It is so funny you mentioned the string method, I was just talking to my Uncle about this and that is what he said. I really don't understand the concept though. I will try and use Mr. Google to see if I can find some pic's to help it sink in.

    Thanks again!
    #6
  7. mtaqua

    mtaqua Member

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    I mis-spoke they are chassisworks. https://www.cachassisworks.com/c-809-upper-control-arms.aspx

    For caster and camber adjustments you turn sleeve, and then use the jam nuts to hold it (much like you do with tie rods ends). It is brilliant. They are not cheap, but well worth it. You might be able to sale you new ones. It can be done with regular UCAS, shims just suck. I had almost no header clearance when I did it with shims, so that made it worse. If you align you can and it holds and you only have to do every few years then maybe they are not worth it. I've aligned mine several times since putting the front end in. I've got adjustable coil overs up front and I've made multiple ride height adjustments, which then I would tweak the alignment because it was so simple. When I finally get to the take my car to the track I will probably tweak some more on the front end, and will be aligning it again.

    You need the tool for the string method. You set the 4 jack stands up on the 4 corners of the car about 2 feet away making a box around the car. Then put the conduit (or an poles) on top of the jack stands. The strings run parallel to the sides of the car. To make sure they are parallel you take measurements from the wheel centers. Once the measurements are all equal you'll have your alignment reference lines. I use chalk an transpose the lines to the concrete and use both the string and the chalk lines. The tool attaches to the wheel. For camber it is just the lateral tilt of the wheel, there a bubble you center up to the appropriate measurement. For caster you turn the wheel from center one way (15 degrees, using the lines for reference), set the tool, turn the other way and make a measurement. Then adjust the caster, remeasure. If you make and adjustment on the UCA it will change camber on you have to go back and forth. If you use the adjustable strut rod the camber won't change as much and you might not need to re-correct. Once you get it close it goes quick. The problem is it takes patience, time, and trial and error. A shop with a kid that normally does the same job with a computer that tells him exactly what to adjust will probably have none of those things. With shims there is almost no room for man sized hands to get in there. It almost requires two people (or you'll drop the stack of shims multiple times). Also, something I did with shims to make it easier was I bent the end of my open end wrench to get in there easier. If you do it, you'll see what I mean. Get a propane torch, vise, and cheap wrench. I don't use turn plates, just trash bags with grease on them. I also try to put 200# of weight in the drivers seat.

    here is the one I use
    View: http://www.youtube.com/watch?v=ZwyfUXsXTV4
    there are others that work too. I think I might get the toe adapters for it, I usually just put a straight edge on the tire to do the same thing.
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  8. bizkit1976

    bizkit1976 New Member

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    Thanks for the video! Quick question...how do you read the 15 degrees on the caster setup if you do not have those plates? Does the Fasttrax tool have that reading as well?

    Oh, almost forgot, thanks for the link to the UCA, I couldn't find them before. That is an awesome design but they are too far out of my price range at the moment. Maybe one day! :)
    #8
  9. rbohm

    rbohm Founding Member

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    a couple of things to think about;

    1: regarding the caster problem, the car might have been hit on the right front at some point in its life, and was never properly repaired. you might take the car to a chassis shop and have them check it over.

    2: regarding adjustable strut rods, if you are using the stock rubber bushings in the lower arms, be careful how much caster you dial in with the strut rods as it pus pressure on the bushings in a manner that was not designed for at the factory. if you are using a spherical bearing, like the ones opentracker sells, then you should start with zero caster and zero camber and use only the strut rods to adjust the caster. the spherical bearings have a lot more tolerance for operating at high angles.
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  10. mtaqua

    mtaqua Member

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    one the end of the tool the surface is canted 15 degree, you line the end up with the strings/lines. I usually put a ruler on it to make the angle easier to see and line up with the lines. Good point from rbohm too, I've got opentracker roller bearing LCAs. To much with the normal bushing will probably bind things up.
    #10
  11. v8only

    v8only Active Member

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    I have the open tracker bearings on my lower arms and the rose hill adjustable strut Rods.. just had it Aligned last week and it all came together perfect.... no complaints from Alignment shop

    Sent from my SPH-L710 using Tapatalk 2
    #11
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  12. horseballz

    horseballz Member

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    When replacing upper control arms/shafts, one thing that is rarely checked and even more rarely correct, when purchased, is the centering/relationship of the shaft in the arm. The bushings at the ends of the shaft are threaded and nearly every one I've gotten has the shaft justified one way or the other from centered. The best thing to do is to drive out the bolts that attach the unit to the shock tower and first center the shaft (by spinning it in the bushings) and then continue spinning the shaft 1/2-1 1/2 turns forward for the side of the car you're working on. This will move the arm to the rearward of the car, effectively pre-setting positive caster. The limiting factor as to how far you can make this adjustment is how much clearance there is between the rear bushing/grease fitting and the rear of the shock tower. This helps to reduce the offset number of shims (front to rear) needed to achieve good caster.
    As far as adjustable strut rods are concerned, bear in mind that using them to increase positive caster pulls the lower ball joint closer to the front of the car which also brings the whole wheel forward in your wheel opening AND in relation to the rear axle. If the upper arm/ball joint is farther forward on one side than the other, by the time you get your caster where you want it, one wheel center point ends up farther forward than the other side in relation to the rear wheel center points and can cause a "crab tracking" issue! Many/most alignment rack jockeys don't know their a$$es from their elbows when it comes to the overall suspension geometries of these cars and I tell you sincerely that the only way you will end up truly happy with your alignment is to learn how it really works and do it yourself. IT IS NOT THAT HARD and if you have had the skills to replace the parts you certainly have the skills to do your own alignment the way YOU want it!

    Some helpful reading:

    http://home.bresnan.net/~dazed/suspension101

    http://dazed.home.bresnan.net/bump

    http://home.bresnan.net/~dazed/drop
    Just My $.02,
    Gene
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  13. bizkit1976

    bizkit1976 New Member

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    I am having a hard time visualizing this. Can you explain it a little more? The only shaft I remember had a bushing around it. Is this the one? I didn't think this came out? I apologize, as you can tell, I'm new at this. I definitely did not take any bolts out, I just installed them as is....

    Thanks again for all of the input!
    #13
  14. bizkit1976

    bizkit1976 New Member

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    Quick update...my adjustable struts have not arrived yet. I have made an appointment to get my car's frame looked at. Supposedly this shop can download the right spec's and let me know if she out of whack. I'm just waiting on a call back. In the mean time, I am replacing my radiator and power steering pump as they both are leaking. Maybe this will get my one step closer to a leak free car! :)
    #14
  15. horseballz

    horseballz Member

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    If the shop "downloads the right specs" they will likely be stock factory specs without the Shelby drop and for bias (not radial) ply tires and set to these specs your car will drive/handle like crap. READ the links I provided and I will try to post a drawing of what I mean about the relationships of wheels to each other to help you understand.
    Just Trying To Help,
    Gene
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  16. horseballz

    horseballz Member

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    Here is a pdf drawing:

    [​IMG]

    It shows a drastic 10 degree positive caster to give a better idea of what is happening. This is what will happen if all caster is adjusted at the lower ball joint and it would be opposite if all is adjusted at the upper. This is just to give a general idea. The real trick is to get your caster where you want it while maintaining the same wheelbase on both sides of the car, even if the wheelbase ends up a bit more or less than 108". As long as both sides are the same. And, yes the bushings at the ends of the shaft that bolts to the shock tower are threaded (as are the ends of the shaft) and if you drive the bolts that mount it to the shock tower out you can spin/screw the shaft forward and/or rearward in the upper control arm. I realize the drawing may be a bit crappy/confusing, but don't be afraid to ask questions. Once you get the hang of how each adjustment affects the others it will become second nature and you will wonder why people pay big $$$ to have some shop make a mess of it all! The gauge, referenced by mtaqua, above, is fairly inexpensive and easy to use. It will pay for itself in one use and allows the option to try different setups to find what you like best.
    HTH,
    Gene
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  17. bizkit1976

    bizkit1976 New Member

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    Gotcha...the factory spec's I was referring to was the frame specs. I have the alignment specs that everyone uses for the new tires/Shelby drop. I have a feeling that I won't be able to get her aligned properly until I figure out what is going on with the passenger side.

    I appreciate the help...I'm just still confused on what needs to be turned/removed with the upper control arm

    Thanks again!
    chris
    #17
  18. horseballz

    horseballz Member

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    This shaft:

    [​IMG]

    Is part of this upper control arm assembly:

    [​IMG]

    Note that the red arrow points to one of the two bolts that need to be driven out as well as the arrow also pointing to the shaft (first pic) that I spoke of.

    Also note in the first picture of the shaft that it has threads on each end of it. If you remove those two bolts the shaft can be threaded/twisted/turned to justify it either direction in relation to the rest of the assembly.
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  19. bizkit1976

    bizkit1976 New Member

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    Thank you very much!!!! I have read about this but could never picture it. I know see what what everyone is talking about and I did not even look at this when I installed the UCA. Now in relation to being centered, which way would I want the eyes of the shaft (towards the front or rear of car) to gain increased caster?

    I really appreciate you taking the time to break this down for me. Once I know which way to offset, I will be tearing down the passenger side and looking at this. I guess practice makes perfect. On a side note, my adjustable strut arms came in so I might as well change as many things as possible so I am sure I will need a new alignment! I will be looking for caster/camber readers today!
    #19
  20. dennis112

    dennis112 Active Member

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    Spin the shaft eyes toward the front of the car, which will move the UCA (and the ball joint) rearward.

    Note that the direction that you spin the shaft (CW or CCW) will be opposite from one side of the car to the other.
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