Alignment Question

[gbarber]

I just replaced some of my front suspension parts (upper and lower arms, sway bar and bushings, and strut rod bushings), and I am trying to align the front end. I also did the Shelby drop while I was at it.
I was trying to set it up as follows:

1/8" toe
0 to -.5 camber
+1.5 to 2 caster

The driver side isn't a problem. I can get those settings.
The passenger side, however, I'm running into a problem. I can't get neg. camber and pos. caster at the same time. With no shims in place, I get -1/8* camber, and -2 1/4* caster. If I shime the front of the upper control arm to get the caster pos., I end up with pos. camber.

My real question is, if I can't get the settings I want, which one (camber or caster) is it better to sacrifice? Should I get it as close as possible to what I want, and then match the driver side to it?

 

[Opentracker]

It's possible that the shaft isn't centered in the arm. You would have to take the car apart again to find out. The issue with these cars is to have both sides the same. Both sides with the same camber and caster. If you take it apart again, you can knock the bolts out and give the shaft a half or full spin from center to put in some caster. You end up with a right and left arm.

John

 

[gbarber]

Thanks for the help.
Does the arm need to be centered? How far off center can you safely go? I took it apart and turned the shaft so that the shaft was about 1/8" off center (shifting the UCA toward the rear of the car). It helped some, but I'd still like more caster.
Right now at 0 camber the caster is -1 1/8*. I hate the thought of ripping that thing apart again, but I'd like to get the alignment close to being correct.

 

[stangman67]

When I did my 67 last summer, I too was having troubles, so I used the lower strut rod to make the adjustment. I actually didnt use shims that time. I didnt see what year yours was, so I dont know if you have a eccentric on the lower control arm for the camber. To bring your negative caster to positve, loosen the nut on the srrut rod towards the rear, and then tighten the front nut. This will draw the LCA forward, giving you your positive caster reading. Watch the LCA bushing, you may have to give it altittle extra clearence in that area with a big screwdriver.

 

[gbarber]

I have a '66, so I don't have the eccentric on my LCA. You may be onto something though with the strut rod. I just replaced the right side strut rod with a new one from NPD. I had a heck of a time getting the new strut on. It really pushed the LCA to the rear of the car. I had thoughts that maybe they sent me the wrong strut rod, but after measuring the left side rod, they were the same. The old rod was bent. Something I hadn't noticed until I started with this suspension project. I'll dig into it again tomorrow, and hopefully figure it out. It can't get any worse. I did correct the 1 1/8" toe out the car had before today. Wonder why there so much wear on the inside edge of the tires.

 

[TT670]

I have a '66, so I don't have the eccentric on my LCA. You may be onto something though with the strut rod. I just replaced the right side strut rod with a new one from NPD. I had a heck of a time getting the new strut on. It really pushed the LCA to the rear of the car. I had thoughts that maybe they sent me the wrong strut rod, but after measuring the left side rod, they were the same. The old rod was bent. Something I hadn't noticed until I started with this suspension project. I'll dig into it again tomorrow, and hopefully figure it out. It can't get any worse. I did correct the 1 1/8" toe out the car had before today. Wonder why there so much wear on the inside edge of the tires.

Since you had a bent strut rod have you taken into consieration that the car may have slight accident damage thats causing you grief? It might not be a bad idea to take some chassis measurements.

 

[Opentracker]

Thanks for the help.
Does the arm need to be centered? How far off center can you safely go? I took it apart and turned the shaft so that the shaft was about 1/8" off center (shifting the UCA toward the rear of the car). It helped some, but I'd still like more caster.
Right now at 0 camber the caster is -1 1/8*. I hate the thought of ripping that thing apart again, but I'd like to get the alignment close to being correct.

No, the shaft does not need to be centered in the arm in my opinion. The new ones should be centered but I have seen some new ones that aren't. I would knock the bolts out and center it before putting it on a customer car. An arm I took off one of our cars was a full spin from center and it didn't show any odd wear patterns, so now I give the arms a full spin from center to add caster.

I have never seen or herd of anyone doing this before. It is a new trick and I have not tested it on any cars but ours.

It's possible that your Shelby drop holes are not the same on both sides. I don't know how many times you have done it but mistakes can happen. If the template was backwards on one side it would be hard to add caster to that side.

Again, the main issue is to have the alignment settings the same on both sides.


John

 

[gbarber]

TT670,
You're right. There very well could be some accident damage that I am not aware of. I don't know too much about the history of this car. I can say that I have taken most of the frame down to bare metal and repainted it. I didn't see anything that suggested collision repair. That's not to say that a good hard hit on a curb couldn't have bent something, causing alignment problems. I'm not all that sure what measurements to take to check the chassis. Actually, I've put so much work into this car that I almost would rather not know if something is bent. Unless it was something easy to fix.


Opentracker,
I did try rotating the shaft another half turn, but that caused the control arm to rub the shock tower on the front side. Did you have to grind the edge of the control arm where it comes close to the shock tower? I ended up rotating it back to center and going from there.
The Shelby holes are drilled correctly. I was very careful on that.



If I had to choose neg. camber or pos. caster, which one is more important?

 

[Opentracker]

Opentracker, I did try rotating the shaft another half turn, but that caused the control arm to rub the shock tower on the front side. Did you have to grind the edge of the control arm where it comes close to the shock tower? I ended up rotating it back to center and going from there.
The Shelby holes are drilled correctly. I was very careful on that.



If I had to choose neg. camber or pos. caster, which one is more important?

I did have to peen the shock tower where the zerk fitting is and where the arm got close to the shock tower. I did a bit of grinding on the arm but not much. Just enouph to smooth it out.

We run 0 to .5deg neg. camber on all of our street cars. I would work to get the caster even on both sides. They both (caster-camber) should be even or the car will pull to one side. You could give the arm just half a spin and give it a go.

We run this on all of our street cars:

0 to .5deg. neg. - camber on both sides

1.5 - 2deg pos. caster on both sides

1/8" toe in


John

 

[gbarber]

Well, I got the idea to check the bushing end of the strut to see if it somehow wasn't seated right. After removing the front half of the bushings, it looked like the nut was running out of thread before the bushings were compacted to 60-80lbs of torque. I got the bright idea to add another washer onto the front side of the bushing to try to squeeze them together a little more, and perhaps gain a little caster. It worked to some degree. After tightening the nut to 80 lbs, I pulled the caster to 0 with +.25 camber. The caster was -1.125 before. So I thought maybe I could add another washer, just in case the nut was still bottoming out. I guess those nuts are self-locking, single use nuts? I realized the mistake I made as I was trying to get the nut off for the second time. The threads on the strut aren't very pretty. I need to but a 9/16-18 die to try to fix it.

Maybe I should have paid someone to align this thing.

 

[gbarber]

Opentracker,
Thanks for all of your help! I'll work some more on it tomorrow.

 

[68rustang]

What are you guys using to measure your caster? Will an angle finder on the spindle be accurate enough until I finish the car and take to an alignment shop? What is the point of the Castellated nut and cotter pin on the end of a 68 strut rod? By my guesstimates it will not be anywhere close to the front adjusment nut when everything is aligned. Unless it is a failsafe incase the front nut lets got it will still capture the strut rud?