Vintage Mustang Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
1,667 Posts
Discussion Starter #1
After much head scratching and talking with a drag racer, an alignment shop owner who has run asphalt cars and the owner of a machine shop(free consulting, LOL) it was decided the best way to fix my non-adjustable strut rod delima was to simply drill a second set of holes in the ends of my strut rods. Threading the non-adjustable rods is not a good idea and I can explain why if you all want to hear about that. The new holes would give me about 3/4 inch of pull forward. My alignment guy said that would change my -1.2 degrees current caster into something positive.

Well I did it, uh, drilled the holes. Thanks are extended to my friend for the use of his shop drill press. I had to grind the bottom of the steering stop brackets flat but it was no a big deal. Well they are installed and on the ground! I checked the steering stops and they appear to still be working fine. The extra tip end of the strut rods is no consideration.

I have not taken it back to the alignment shop yet but this is up next. It looks like I have "awl kinda caster"(Texan for a lot) now and a new concern. My front tires come dangerously close to the front of the fender lips. Maybe taking some of the old caster shims back out will help fix this. Otherwise it looks like I may have to "massage" those a little. I will post the alignment results once we know how much good it did.
 

·
Registered
Joined
·
21,275 Posts
1st., let me say I haven't done any front end alignment work so take it for what it's worth.

Stock caster for the early cars are about 0 degrees. I just saw specs. for stock located arms with a 1" drop to set the caster for 1 to 1.5 degree +. And for the Shelby drop, 2 + caster.

I know from the other day, you said you relocated your arms. My big question is how come you're having such a problem? This is more of a general question in reguard to 65-66's and not you personally. Are 65-66's that much out of wack from the factory that cars could have as much - caster as yours. even after you relocated the arms or did you car have some serious collision damage from a PO?
 

·
Registered
Joined
·
1,667 Posts
Discussion Starter #3
Its a good question that I don't know all of the answer to. At least a part of it is that I run higher in the back end which changes the front pitch of the car. Maybe my 71 mustang spindles that I'm running had something to do with this.

I used the Branda template for my control arm lowering and it was dead on for the bolt holes. I do have aftermarket control arms. Part of it was that we(thats me and my alignment guy) were just unwilling to put the amount of shims in there that it would take to get the caster I wanted even though we had enough threads to get it to better than 0. When you look at how those strut rods are installed they just go from the frame rail back to the lower control arm at a slight angle but almost straight. I don't see how that could get much out of whack. The whole frame rail would have to be compressed or something. My montecarlo and export brace fit fine so that is at least an indication that its close to true. I don't have any trouble with 4 corner alignment either.

http://members.aol.com/macstang/Gifs/hamcar.gif
 

·
Registered
Joined
·
865 Posts
I have been following the caster dillema as well. From my experience I do not know how a 65-66 with manual stearing can be driven with say +2 caster. My car was set at +1 with my new suspension and it was at total @#$%^ to stear at low speeds. SWMBO really complained and I didn't like it either. I had the car realinged after installing different springs to 0 and what a difference. Much easier stearing and no wondering or any types of stearing problems. I think it is amazing hoe such a small change makes such a big difference.

I looked at my shim packs and they are preaty big. I use a specialty shop who knows old cars and can align them properly with the shims.
 

·
Registered
Joined
·
21,275 Posts
Ah, the pitch from the tall tires is most likely the culprit. I guess the early cars are really suceptable to rake in relationship to alignment. I completely failed to think of this. Good point.

Hey, maybe you can order some high lift springs for the front from J.C. Whitny to solve your caster problems*LOL*
 

·
Registered
Joined
·
7,671 Posts
As I recall, the Branda template moves the UCA location down 1" and back 1/8". Moving the 1/8" rearward would give you some +caster, no?

As close as the front of the tire is to the fender, I would be inclined to make a solid spacer for the foward bolt on the UCA as opposed to bringing the lower arm foward.
 

·
Registered
Joined
·
21,275 Posts
I asked that too, yesterday. I was wondering if he had something radically wrong with the front clip from the factory to still have - caster, even after the relocation. Yes he did use a template.
 

·
Registered
Joined
·
10,587 Posts
Hopefully some of the engineers can correct me, but, if my measurements of a spindle, estimation of the ball joint pivot points and understanding of geometry are correct, each movement of the lower control arm forward by 3/16" or so should equal one degree of caster.

Just wanted to pass that along...

Be sure to check your steering lock-to-lock after the modification so you don't have any interference.

Unless I missed something (and don't consider liablility), I could easily convert the struts on the D-coder into fully adjustable ones, though obviously not without the benefit of my machines, which at times is my liability...I've had them so long I can't remember a time when I did things any other way...*G*

Once you get everything together and working, let us know how it worked out!
 

·
Registered
Joined
·
926 Posts
Actually I don't think the 1" drop template actually changes the caster much on the 65-66's. Yes, the template goes down an inch and then back 1/8". But the upper A-arm mounting holes aren't level. The back hole is lower than the front so the A-arm is slightly tilted back, I suppose so it reacts better to the shock of hitting potholes and such that would try to knock everything backwards.

Anyway, since the mounting holes are tilted some, if you had a template that just went down 1" from the holes perpendicular to the line between the two holes, you'd actually be moving the upper arm forward some. The 1/8 back part of the template makes sure you are actually moving the holes straight down vertically. Hope this makes sense, it would be easier to draw.
 

·
Registered
Joined
·
1,667 Posts
Discussion Starter #10
Well I also have the Shelby quick steering kit which helps some and it is a drag strip car so I really want it to go in a stragiht line well. Its good to know this though. If we take some shims out I may shoot for just 1 degree of caster which based on Pat's guestimation formula it looks like that is about where it should be. If you didn't realign your front end after the caster that would make it really hard to steer.
 
1 - 10 of 10 Posts
Top