Any way to get more caster adjustment without newer adjustable CA?

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Mopar to ya

Mopar to ya

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I had my 73 Dart Sport on the hoist for a few weeks while the transmission was being rebuilt so I took advantage of the hoist time and put in all new Moog front end parts. I mean everything. Upper and lower ball joints, upper and lower control arm bushings, idler arm, pitman arm, inner and out tie rods and sleeves. When I aligned it, I used the max street performance specs, but they want up to -3.0 degree of caster to help it track. With the eccentrics maxed out the most I can get is 0 degrees. That is factory spec, but it does tend to wander just a bit. Without going to different, newer control arms that have more adjustment built in, is there any way to get more (or less) caster?
 
You mean positive 3* caster? +3. Negative caster is for bias plys. Radials need positive caster for better tracking.
 
Your idea sucks, but only because those bushings are a pain in the *** and I just did them. Had I known the offsets were available I would have bought them right away. Oh well. Live and learn ... and do things twice. Thanks Beast!
 
72bluNblu said:
You mean positive 3* caster? +3. Negative caster is for bias plys. Radials need positive caster for better tracking.
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Yup. Positive. Spec is -2.0 to +3.0, more positive being better. Some people say up to 5 degrees is sometimes necessary. I can get mine to zero, but that's all the adjustment I can get. It tracks pretty well, and I don't know if I'll tear it apart again this year, but I think I want to get it a little better. It will track better in panic situations or handling situations that way as well.
 
Mopar to ya said:
Yup. Positive. Spec is -2.0 to +3.0, more positive being better. Some people say up to 5 degrees is sometimes necessary. I can get mine to zero, but that's all the adjustment I can get. It tracks pretty well, and I don't know if I'll tear it apart again this year, but I think I want to get it a little better. It will track better in panic situations or handling situations that way as well.
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Yeah you put -3 in your original post that's why I asked.

You probably won't get more than +3 degrees of caster even with the offset bushings, but that's usually enough for most applications. If you want more than +3 degrees of caster you'll probably need tubular UCA's. The more you run the more stable it will be, but if you run much more then +3 degrees of caster you'll probably want power steering as it will raise your steering effort as well.
 
Mopar to ya said:
Your idea sucks, but only because those bushings are a pain in the *** and I just did them. Had I known the offsets were available I would have bought them right away. Oh well. Live and learn ... and do things twice. Thanks Beast!
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:D I know, I was thinking that when I typed it.
 
how did you do your alignment and what the position of your eccentrics on each side.
i've always been able to get my upper balljoint behind the lower and have never seen the need for those offset bushings...are your lower control arms in good shape?
 
The caster is also somewhat dependent on the ride-height as; the strutrod moves the LCA around some, and; the UCA moves the upper BJ back and forth.
The trick in the alignment, is to let all that happen without letting the camber stray too far, and jacking the toe-in around.
3 to 3.5 positive is nice at the bigend, and also at cruising speed for hours on end. It is definitely worth the getting. For me zero sucked!

FWIW; the offsets got my car over 3.5* caster at zero camber.And I yanked the LCA ahead for another .5*. I gave up a little to get some negative camber. My 245s wore flat across at .5/.8 neg camber, with 30/32psi. And those stickies cornered pretty good.
 
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AJ's right on, it depends on the ride height of the car and the camber settings as well.

If you want some negative camber (and you should with radials) and you're lowered a little you'll need the offset UCA bushings to get a decent amount of positive caster.
 
...that is why when the front is hi it is impossible to get enough caster.
although crude, if your steering self centres while driving and it is
very hard to dry crank in a parking lot (which you should only do as a test)
you are probably fine.
 
If you can shorten the effective length of the lower strut rod without causing the lower control arm to bind throughout its full range of motion, you will gain significant positive caster. This can be done by cutting the rubber bushing a bit or machining the forward shoulder on the rod a bit further back.

Adjustable strut rods make this an easy update. Be sure to keep an eye on the general position of the front wheel in relation to the fender openings (front to rear) when performing this mod.
 
jbc426 said:
If you can shorten the effective length of the lower strut rod without causing the lower control arm to bind throughout its full range of motion, you will gain significant positive caster. This can be done by cutting the rubber bushing a bit or machining the forward shoulder on the rod a bit further back.

Adjustable strut rods make this an easy update. Be sure to keep an eye on the general position of the front wheel in relation to the fender openings (front to rear) when performing this mod.
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This is true, but the most important part is to ensure there's no binding of the LCA throughout it's range of motion. Don't sacrifice the free movement of the LCA to get positive caster, keeping the LCA moving freely is the first job of the strut rod.

I use adjustable strut rods on my cars to fine tune things, and I've found that I can usually get some additional positive caster by shortening the strut rod length compared to stock without causing any binding within the range of motion of the LCA. That's with adjustable strut rods and poly LCA bushings. Cutting the strut rod bushing down and using factory strut rods would shorten the effective length, but if you shorten it too much and get binding you need new bushings. It would be a lot more trial and error than using an adjustable strut rod. The range of factory tolerances on these cars is such that what works for a strut rod length on one car might not necessarily work without binding on another.
 
i think early and late strut rods differ slightly.For those who have replaced their
originals with the wrong ones it may create a caster problem
 
ir3333 said:
i think early and late strut rods differ slightly.For those who have replaced their
originals with the wrong ones it may create a caster problem
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They do. They use different thickness bushings, so the shoulders and lengths of the strut rods are not the same. If the strut rods are paired with their correct bushings, the effective length of the strut rod is the same. So, what you can't do is use early bushings on a later strut rod or vice versa, that changes the effective length. You can use later strut rods on an earlier car IF you use the later bushings as well. Or earlier strut rods on a later car if you use the early bushing style.

Not all the aftermarket bushings are the same thickness as their respective originals either, so you can unintentionally change the effective length of the strut rod even if you use the "right" bushings if they're not a good match to the OE specs.

Which are all reasons I use adjustable strut rods. As the modifications add up (poly bushings, gusseted K members, tubular UCA's, etc) the length that the strut rods need to be to prevent binding can change, and the only way to be sure is to set the length, check for binding and repeat until it works. Or as jbc426 suggested, install the stock strut rods and check for binding, and then alter the bushings to get the right effective length for your car.
 
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