Camber adjustment/rack and pinion

[Nkempski]

Hi Everyone,

I have a really bad weld on one of the shock towers where the camber adjusts. I cannot get the alignment right. I have a 1973 Dodge Dart Swinger. It looks like the car may have had some structural damage at some point in its lifetime. Anyway, my question is, if I install a new front end rack and pinion set up, how does that align? I see that the upper control arms still attach to the same shock tower. Am I going to run into the same problem with the camber not turning? Or, it it just attached there and then aligns a different way?

I know there are other ways to go about this. I really do not know how a rack and pinion alignment works. I'm looking at getting the entire front end. K Member, coil overs, rack and pinion. Will I still run into the same alignment problem with the camber? That's really my question.

Thank you in advance.

 

[devilchicken]

I have an aftermarket modern coil over suspension with rack and pinon on my scamp and yes the upper control arms mount and align in the same way as stock and as far as the rack its only adjustment is with TOW and has nothing to do with caster or camber.

 

[Syleng1]

2 things-
I agree “toe” has nothing to do with camber because you have a rack and pinion steering. Camber and caster are the first adjustments on a proper alignment.

so if you have damage- you need to fix that first or you will never get the car dialed in. After that is set …. Then you set toe.

 

[TT5.9mag]

It depends on what upper control arms you end up with. The SPC arms and Hotchkis arms (and I’m sure there are others) have heim joints that can be used to adjust camber. As others have said the type of steering you have makes zero difference in camber adjustment

 

[72bluNblu]

If the car has damage you need to get the chassis checked. Installing a coilover conversion won’t fix a bent chassis.

 

[Nkempski]

If the car has damage you need to get the chassis checked. Installing a coilover conversion won’t fix a bent chassis.

There's a weld on the shock tower that is where the camber bolt turns. I can get it to turn when the wheels are on the ground, but not when it is up. Upon further research, the problem might be a bad bushings in the lower control arms. I'm going to replace both of those first.

I'm have uneven tire wear on the inside of the tires. From other posts, it sounds like the lower control arms are something to look at, in addition to a number of other things.

Nothing appears to be bent, and it is happening on both tires. I brought it to my mechanic and they blamed the bad weld on the shock tower. To me, that only explains one side of the vehicle. The wear is on both sides. The lower control arms are the only thing I did not replace when rebuilding the front end.

This is my first build, so I'm learning a ton. Thank you for all of the responses. Definitely helps me to rule out an expensive front suspension coil over unit.

 

[72bluNblu]

Do you have any pictures of the bad weld?

It may not even be contributing. As you said, if the LCA bushings are worn out that can cause poor tire wear. Or just a bad alignment in general. But if the bushings and ball joints are worn out it may be impossible to get the alignment set up properly. What alignment have you been trying to get?

 

[Jeremiah (jd)]

What problems are you having? Also what specs are you shooting for? Adjustable strut rods cnn help get the desired negative camber while achieving positive caster sweep. In my experience adding length to the strut rod will increase positive caster with the rear uca cam all in and the front cam all out. Final adjustments usually end up with the rear cam all in and the front cam at about 2 o clock on the pass side and 10 o clock on the driver side. Toe 1/32-1/16" in.

 

[72bluNblu]

What problems are you having? Also what specs are you shooting for? Adjustable strut rods cnn help get the desired negative camber while achieving positive caster sweep. In my experience adding length to the strut rod will increase positive caster with the rear uca cam all in and the front cam all out. Final adjustments usually end up with the rear cam all in and the front cam at about 2 o clock on the pass side and 10 o clock on the driver side. Toe 1/32-1/16" in.

Exactly the opposite. Lengthening the strut rod would decrease positive caster. Positive caster leans the spindle back, so pushing the bottom of the spindle back by lengthening the strut rod would make the caster worse, not better. Shortening the strut rod improves positive caster.

Regardless, the strut rod length shouldn’t be used to tune the alignment specs. The most important function for the strut rod is controlling the movement of the LCA, so, if you have adjustable strut rods the length should be set so that the LCA moves freely through it’s whole range of travel without any binding.

 

[Jeremiah (jd)]

Exactly the opposite. Lengthening the strut rod would decrease positive caster. Positive caster leans the spindle back, so pushing the bottom of the spindle back by lengthening the strut rod would make the caster worse, not better. Shortening the strut rod improves positive caster.

Regardless, the strut rod length shouldn’t be used to tune the alignment specs. The most important function for the strut rod is controlling the movement of the LCA, so, if you have adjustable strut rods the length should be set so that the LCA moves freely through it’s whole range of travel without any binding.

Assuming everything is in the correct position in the first place.

And then there is reality.

I do alignments often and depending on the car what I stated above is true in my experience. Obviously taking the adjustment to an extreme will cause binding, etc. My last alingment was yesterday, yours?

 

[HemiDenny]

Please notice the aluminum spacers and the adjustable (in / out) poly ends. Combined they allow for maximum adjustment without putting the control arm in a bind. HDK builds the control arms to be installed as follows...

both spacers stacked to the rear........3 degrees of positive caster (manual)
spacers on each side......................4.5 degrees of positive caster (aggressive manual)
both spacers stacked to the front......6 degrees of positive caster (power)

it is also possible to adjust the ends in/out to achieve your desired camber / caster spec and have the cam alignment adjusters both at a 12 or 6 o'clock position (center)....best to eliminate bind.

HDK also offers chromoly tubular OEM replacement arms to achieve the same results....both in the small (early thru 72) and the large (73 and up) UCAs. $298 for both assemblies including adjustable UCA bump stops.

if you want to discuss this or any other specific questions or concerns, feel free to call. Denny / HDK 304-939-0097

 

[72bluNblu]

Assuming everything is in the correct position in the first place.

And then there is reality.

I do alignments often and depending on the car what I stated above is true in my experience. Obviously taking the adjustment to an extreme will cause binding, etc. My last alingment was yesterday, yours?

First, I don't care if you're doing an alignment right now while you type with one hand, it doesn't change the facts. Doing them often also does not change the facts, and a quick review of this board will show you that there are plenty of shops out there that perform alignments professionally that have royally screwed up the settings on many members cars. Which is why I do my own alignments and have for years. And it doesn't matter if I've done a hundred or a million, the A-body suspension geometry is still the same.

Second, it doesn't matter if everything is in the right place to start. Even if the strut rod is too short, lengthening it pushes the lower ball joint toward the rear of the car. If you keep the upper ball joint in place and move the lower balljoint rearward, that decreases the amount of positive caster, or adds negative caster, depending on what your setting was to begin with. Now, if the strut rod is too short to start off with it needs to be longer as that will cause other issues, but your caster setting will still change toward the negative. Really easy to see, if you move the bottom back and keep the top in place, you're reducing positive caster.

When using adjustable strut rods on these cars the adjustments do not have to be taken to "extremes" to induce binding. Setting the adjustable strut rods on my own cars I have found that the LCA's can go from completely free with no binding at all from bumpstop to bumpstop to getting binding at the extreme ends of the range of travel with only a full turn on the adjustable strut rods. Now, that can depend on the other suspension components used and how the ride height and range of travel are set, but it's not like an extreme change in length is necessary to create binding. If you use Delrin or poly LCA bushings any binding or resistance becomes more obvious, with rubber bushings at the LCA you're always working against the resistance from the flexing rubber.

And the fact remains, the purpose of the strut rods is not to adjust the caster setting. They're there to locate the LCA, and their length (if adjustable) should be set so the LCA travels freely, not to get to a specific alignment setting. That's what the eccentric bolts are for.

 

[MoparLeo]

True, plenty of "mechanics" with lots of experience doing things wrong . They also tend to specialize just like people Drs. Brake guys tend to not do much electrical or tune up diagnostics, but they do brake services. Your mechanic may not be a front end guy. A complete inspection of the front suspension including the tires is a normal part of an alignment service. You don't align worn, loose or damaged parts.