Front End Alignment

[clemsonteg]

So I am working on the suspension of my 70 C10 after some changes recently and I am having a hard time grasping the concept of adjusting for caster. Toe and camber are easy, but the sources I am seeing online don't match up with the way by brain is seeing this.

From everything I have read so far, positive caster is what is desired and in it's simplest form, that should be the bottom ball joint being more forward than the top ball joint.

What is throwing me off is the adjustment for caster. Several sources online indicate that to increase caster, place shims behind the rear most adjustment stud, or remove shims from the front most stud. To me, that seems like it would push the upper control arm and the ball joint attached to it forward, not back.

Am I missing something?

[67ChevyRedneck]

Read your post wrong, If you want + caster the upper ball joint has to be moved back. Bottom ball joint is stationary. By adding a shim in the front (toward bumper) or removing to the rear (towards cab) your pushing the upper ball joint backwards, or in a way, "moving the bottom ball joint forward."

Caster is a bit of a pain in the arse because it will mess up your camber, so you have to play a game of compromise.

I did a home alignment on my 65 mustang. A shop that charged me $80 to align it (was even recommended by a friend) destroyed a $300 Set of front tires in less than 3,000 miles. I aligned it myself and put over 5,000 miles on my current tires with no noticeable wear. I plan on aligning my C10 in the next week or two after I finish the drop.

[Fitz]

Originally Posted by clemsonteg

To me, that seems like it would push the upper control arm and the ball joint attached to it forward, to back.

Am I missing something?

Yes, you are missing something. Moving the upper ball joint forward reduces caster, moving it back increases caster.

[clemsonteg]

Originally Posted by Fitz

Yes, you are missing something. Moving the upper ball joint forward reduces caster, moving it back increases caster.

Thanks. After making my post I read a few more articles, and I think the part I was missing is that none of the articles I read last night mentioned if the control arm was mounted inboard or outboard of the frame. After more reading, I think I have figured out that the articles I read last night were all referring to inboard mounted control arms, ours are outboard which means the adjustment is flip-flopped, and that I am not crazy!

[clemsonteg]

Originally Posted by 67ChevyRedneck

Read your post wrong, If you want + caster the upper ball joint has to be moved back. Bottom ball joint is stationary. By adding a shim in the front (toward bumper) or removing to the rear (towards cab) your pushing the upper ball joint backwards, or in a way, "moving the bottom ball joint forward."

Caster is a bit of a pain in the arse because it will mess up your camber, so you have to play a game of compromise.

I did a home alignment on my 65 mustang. A shop that charged me $80 to align it (was even recommended by a friend) destroyed a $300 Set of front tires in less than 3,000 miles. I aligned it myself and put over 5,000 miles on my current tires with no noticeable wear. I plan on aligning my C10 in the next week or two after I finish the drop.

Thanks, Jesse. I am going through the same thing. $80 alignment last time I had it aligned and everything was barely in spec. I would rather do it myself and safe the hassle. For camber I am using a digital level. Did you adjust your camber on the mustang by measuring or by feel?

[67ChevyRedneck]

This may also be helpful, while it applied to my mustang, even if it's "close" for a C10, it should make aligning it easier:

Jesse, according to the Ford shop manual a 1/16" shim on both bolts equals 1/3* of camber change and 1/32" shim on just one bolt will change caster by 1/2*.

[67ChevyRedneck]

Originally Posted by clemsonteg

Thanks, Jesse. I am going through the same thing. $80 alignment last time I had it aligned and everything was barely in spec. I would rather do it myself and safe the hassle. For camber I am using a digital level. Did you adjust your camber on the mustang by measuring or by feel?

Oh heck no (I'm assuming you mean caster - typed camber twice).

http://www.ebay.com/itm/78260-Longac...040161&vxp=mtr

[67ChevyRedneck]

Also, does anyone have any good specs for a dropped truck? There were a lot of posts that popped up in a search, but not a lot of info. My truck is dropped 3.5" in the front, 2.5 spindle, 1" spring.

I was thinking 0 to -0.5* Camber
+1 to +1.5* Caster
1/16-1/8" total toe in.

Don't forget to cycle your suspension either. You're probably going to have to lift it to swap shims, push up and down on the bumper a few times to "resettle" the nose after installing shims. On my mustang the ride height was about an inch higher each time I jacked it up until it was resettled.

[PGSigns]

I based most of my settings on the make it handle thread and the caster mod thread. I think by the time it was all done I was able to get 4 degrees of caster and still keep the camber close to zero. Toe is about the same as you are looking for. With the added camber it drives really good and I am glad I did the mods.
Jimmy

[clemsonteg]

Originally Posted by PGSigns

I based most of my settings on the make it handle thread and the caster mod thread. I think by the time it was all done I was able to get 4 degrees of caster and still keep the camber close to zero. Toe is about the same as you are looking for. With the added camber it drives really good and I am glad I did the mods.
Jimmy

Thanks, Jimmy. What are your thoughts on spending $100 at a shop for an alignment vs. $150 for tools to do an alignment?

[PGSigns]

The shop I use has a very nice machine and it does a 4 wheel alignment. They also can check stuff like bump steer. These guys are good and well worth the money. I have a caster camber gauge but prefer the accuracy of there setup and the expertise they offer.
Jimmy

[clemsonteg]

Originally Posted by PGSigns

The shop I use has a very nice machine and it does a 4 wheel alignment. They also can check stuff like bump steer. These guys are good and well worth the money. I have a caster camber gauge but prefer the accuracy of there setup and the expertise they offer.
Jimmy

Thanks for the input. So far three local shops have let me down in terms of their accuracy and knowledge. I may shop around a little more to see if there is anyone that can do a better job.

[PGSigns]

The shop I use is 2 guys and all they do is alignment. Look for places that all they do is alignment. Also ask some of the local old car guys who they use.
Jimmy