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Hi all mustang heads.
I will post pictures later, but might as well start a discustion.
I have got a pair of global west upper control arms for my 69 fastback.
They call it negative roll, and we did it to make the car steer better.
We used the metal template to lover the control arms.
We also have changed the springs on the front (and rear) to stiffer ones, all bushings are changed.
We also have installed a Borgeson servo steering unit instead of the original servo steering. Tha car is running on 235/15 and 255/15 wheels. Also bigger sway bar.
1. The problem is that the car is runnng like crap. It can not run straight, it will not "self allign" driving it on the road, meaning it will stay in the possition you set the steering wheel in. We have tried many workshops here locally, and no one can figure out how the wheels has to be alligned. Some says the wheels should Toe out, some says Toe in. In my world it should Toe In but how much ?
At the moment it has quite some negative camber. Dont know about the carstor.
Is there some one out there that could help us at bit with this ?

2.
There a quite a lot of steering play in the steering wheel and i can see its in the new steering box. Theres a screw on top of the steering box, but i cant adjust it. It is all new. When the steering wheel are turned to one side and the to the other, there are no play. Only when it has been sitting there for a while. Can you also help out with this ?

As said, i will post pictures soon

Thanks
Anders B. Jensen, Denmark
 

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I assume you are driving the car on the street for the most part. I assume since you said you have lots of negative camber that the rest of the alignment is way out also. Tons of camber will cause hard steer. But the caster is what makes the vehicle center steer when all other specs are within tolerance. If your alignment shop cant tell you this then go somewhere else they are idiots. But I am assuming you alignment is way out of spec. To start with stay with factory specs. Then if you want more of a track worthy car. Have someone with track experience perform or recommend a shop near you to tweak it. If its not alignment causing issue could be your steering gear.
 

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I'm not sure what the spec are for a 70 mustang but here is the spec for a 65-66 mustang with shelby drop. You might be able to compare them to the original and work from there.

1. NO more than .25 degrees difference between driver’s side and passenger’s side.

2. +2.0 to +3.5 degrees caster.
NOTE: for cars with Adjustable strut rods. Please attain as much caster as possible using the shims (at least 1.5 to 2.0 degrees), and then use the adjustable strut rods to increase the caster and make the sides the same. Also, please note that the caster difference between the driver’s side and passenger’s side needs to have no more .25 degrees difference prior to the adjustment of the strut rods.

3. -.5 to 0 degrees camber. No positive camber, please. There is no problem having a slight variation from driver’s side to passenger’s side to account for the crown in the road.

4. 1/16" to 1/8” toe in
 

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I forgot to put in the stock specs if you need them they are as follows: Camber range is +.3 to +1.8 degree, Caster range is -.8 to +1.3 degree, Toe range is +.06 to +.31 degree, Cross Caster range is -.5 to +.5 degree, Cross caster is-.5 to +.5 degree I always shoot for center of range scale for street driving and minimal tire wear. Like I said track driving and specs are totally different. If you dont know what tweaks will make for better performance then let a qualified shop do it. but you can always start with the stock specs and see if your bad steering condition is eliminated. P.S these specs are direct from Hunter which is a major alignment machine engineering company and alignment machine manufacturer here in the states.
 

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First of all excessive camber will not cause hard steering; excessive positive caster will. Excessive camber will cause shoulder wear.

Caster is the angle of the steering spindle pivot with vertical viewed from side and it is responsible for returning the wheel to center and also straight line stability. 67-69 Mustangs were spec'd with 0.25deg positive caster (top of spindle leaning backward). The low caster spec is to make steering easier since they didn't come stock with power steering. 1970 has its own spec, I just looked at it on a hunter machine yesterday and I think it was just a minor caster change from 67-69 spec. I can get the actual spec for you tomorrow though to verify what mathew67stang listed.

The low caster number spec'd is bad for returnability of the steering wheel and stability so they spec 0.38deg toe in to try to help with the stability (excessive by modern standards). These specs only work with bias ply tires though. If you have radial tires you will only want about 0.03deg or so toe in you may also see some people say 1/16 inch toe in, they are approximately the same. Basically you want toe to be zero while in motion. Since toe tends to go out when in motion you set slight in static toe.

Adding positive caster will solve your returnability issue but a lot of caster and could make steering effort hard if the power steering (if you have it) doesn't give enough assistance. The factory tolerance (again 67-69) is +-1.00deg on caster so you could go +1.25deg on caster to start with this will give you better returnability and still be on the edge of the factory tolerance. If the steering wheel doesn't return like you want it to you could try adding more as long as your steering effort doesn't get excessively hard.

Also if you did anything to the ride height like lower the front or raise the rear, that will also decrease the caster makeing your returnability worse as well as straight line stability. Taller tires in the back will decrease your caster.

When you take it to the alignment shop, make sure you get a print out of before and after measurements so that you know where you started and where you ended up. I can't stress this enough. I am a tire engineer and troubleshoot this stuff everyday and those print outs are invaluable for troubleshooting handling and tire wear.
 

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I highly recommend going to Daze Cars at DazeCars, Ford Galaxie Mustang tech and restoration for a ton of info about Ford suspension in general and the Shelby Drop in particular. It was a great resource for me when I did the drop on my '65 coupe. I purchased my template and drill bit from him. Lots of other useful/interesting info.

The site also gives specific alignment settings to use after doing the drop -- you should NOT use the factory settings. My experience was that the alignment shop used the original settings even after I insisted they use the new settings. Of course, it was way off. After they re-set to the settings I found on the Daze site, steering and handling was great.

Re the steering box, I don't know about the aftermarket unit you put in, but mine is the original ps unit. It was very sloppy with more than 3" side to side slack. Thanks to advice from another member of this forum, I turned the wheels all the way to the left, slightly loosened the retaining nut, then screwed down the slotted shaft. I screwed in clockwise til it was just slightly snug, then backed off about a quarter turn. It made a world of difference (for a '65 mustang, anyway) meaning that my play was reduced to maybe a bit more than 1".

Hope this is helpful. Good luck.
 
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