Pulls to right

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73Scamp318

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Hey guys, I need some help here.

I recently had a front tire snap a belt on my Duster and took it in to the shop my brother works at to get a pair of used tires swapped on and get the alignment done, since it's been chewing up tires as well. It is a street/strip car with 90/10 shocks and /6 bars in the front.

They had the car over several days time, partly because of the drag shocks and alignment changing when the front is at down-track height. I accepted their latest try with the understanding that I can bring it back if I decide to and they'll take another shot at it.

It currently has a fairly strong pull to the right while cruising down the road but is almost completely gone when under power. I thought it might be a radial pull, so I swapped the front tires side-to-side, but it made no difference.

Here are the alignment specs from the sheet they had printed off:

Left Right
Camber: -0.4 -0.3 degrees
Caster: 4.6 4.9 degrees
Total Toe: 0.20 degrees
At 2+ inches suspension rise, the toe is at 0.70 degrees.

I was thinking that the extra caster on the right side was probably the cause of the pull, but I wanted to get some input on the current settings before I have them jack with it again.

Thanks.
 
If anything I would expect a pull left.

Your car should pull left on caster and right on camber. I wouldn't expect any pull from the numbers posted. A vehicle will pull towards the less positive caster number and it will pull towards the more positive camber number. But usually anything less than .5 degrees will not cause a pull unless both caster and camber are trying to pull the same direction, which yours are not.

Where was your tire wear? Inside edge, outside edge, directionally feathered? Manual steering or power? When holding the steering wheel straight ahead how does it behave? Many times people mistake steering wheel off-center for a pull.

I just took a second look at your numbers. What is your suspension set-up? 5 degrees caster is not a number I would ever expect on a stock suspension, that is in modern car territory so I kinda didn't notice it as unusual.
 
That should straight as an arrow. Cross the two front tires right to left. It will either stop pulling, or pull the other way. If it pulls the other way, chunk the tire you put on the left and replace it.
 
"I thought it might be a radial pull, so I swapped the front tires side-to-side, but it made no difference."






StrokerScamp said:
That should straight as an arrow. Cross the two front tires right to left. It will either stop pulling, or pull the other way. If it pulls the other way, chunk the tire you put on the left and replace it.
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I missed that part. You might try checking brakes. If a hose is bad it can cause a pull by acting like a check valve.
 
i would suspect a brake issue, maybe one side is dragging, or could be a wheel bearing tightening up
 
I would also suggest checking into the brakes or bearings...
 
Another issue is, does the alignment guy know WTF he's doing? I have seen SO many guys make a caster turn with the wheels unlocked and doing it by the TIRE. When doing it like that, you are influencing the caster reading because you are causing the tire to rotate and you're also influencing that rotation. The brakes should be LOCKED when doing a caster turn and they should be done by the steering wheel for the best accuracy. If you see someone turning by the tires, be suspect.
 
The tire wear was on the inside of both tires. I don't have the before settings but I can tell you even though it ate tires, it went down the road straight before I had it aligned.

The front suspension is stock with new bushings put in before I got the car a year and a half ago. It sits a bit lower than it should and I've been thinking about yanking the /6 bars in favor of something thicker.

My brother assured me that the guy doing the alignment is competent and I trust his judgement.

At this point, I'll treat it as a brake or bearing issue and I'll give it a good once-over. Thanks for the ideas.
 
Nope if it is eating tires not a brake or bearing problem I would think.So if you look at the front of your car are the tires leaning in or out?,at the top
 
That toe changing ½ degree (bump steer) with two inch of suspension travel is some of your inside tire wear. Excess camber will also scuff tires quickly. You want zero to - .5 degrees of camber, any more negative and tire start to wear quickly.

If you are set on driving on the street with sloppy drag race front shock, your front end ride height will be all over the place. Worn out weak slant six bars drag racers love aren’t helping any.

Thirdly, if technician did not properly set ride height before setting camber, caster and toe, the car will not handle correctly.

Check the ride height of both sides using the method outlined in FSM. If ride height is not correct, take it back, along with the FSM open to frontend line up page.

I accepted their latest try with the understanding that I can bring it back if I decide to and they'll take another shot at it.
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This statement is cause for concern, the tech knows he has not done a proper job because he does not know proper Mopar torsion bar alignment protocol. He drove it, felt the pull, and can’t figure where it is coming from.
 
I think the eatin tires and pullin are two different animals. The eatin tires is not enough toe. It only shows .2 of a degree. That ain't enuff. lol
 
Okay, so I should probably make sure that the issue is clear. I took the car in for an alignment because it was eating tires. This place had never touched the car before last weekend. Prior to being taken in, it was chewing up the insides of both front tires and went fairly straight, slightly drifting to the right going down the highway.

As my own rule, no one but my brother, my dad, and I ever climb behind the wheel of this car. I have another brother that I have yet to let into the driver's seat, so I was not going to let the tech drive it. If the tech had been around when I picked it up, he would've been riding shotgun.

I am looking at the bearings and brakes tonight. If I don't find anything, I'll be looking closer at the suspension. I was told that I was welcome to bring it back tomorrow afternoon if I want and they'll throw it back on the rack.
 
73Scamp318 said:
As my own rule, no one but my brother, my dad, and I ever climb behind the wheel of this car. I have another brother that I have yet to let into the driver's seat, so I was not going to let the tech drive it. If the tech had been around when I picked it up, he would've been riding shotgun.
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Part of the issue is right here IMO........How can the tech help U if U don't let him drive it ? That's a VERY important part of the alignment procedure....a before and after test drive by the tech.

Good Luck :cheers:
 
As much as it sucks I have to agree.




6pk2goDemon said:
Part of the issue is right here IMO........How can the tech help U if U don't let him drive it ? That's a VERY important part of the alignment procedure....a before and after test drive by the tech.

Good Luck :cheers:
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StrokerScamp said:
The eatin tires is not enough toe. It only shows .2 of a degree. That ain't enuff. lol
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A lack of toe in won't eat tires. The tires would prefer to run straight down the road, ie, 0 toe. That would cause the car to wander a bit on the steering side, but you wouldn't see a tire wear issue.

Too much toe will wear tires. Too little will not. .2 degrees is roughly 1/16 of an inch anyway, which is just fine. I have almost 40k miles on my Challenger with 1/16" toe in and no adverse wear, on either set of tires its had.

The caster adjustment can cause it to pull- but not with those numbers. And caster isn't a tire wearing adjustment. If the numbers are accurate, yours is about perfect. A little cross caster is usually how everyone deals with road crown.

Camber is a tire wearing angle, but again, not with those numbers. -.3 and -.4 degrees are pretty conservative camber numbers, and .1* difference between the two won't cause a pull.

That much bump steer is a little unusual, but maybe thats just because you're getting a lot more travel with those /6 bars and drag shocks? You say the bushings were replaced- all of them? Seems to me there's some extra play in the system somewhere. I also find it interesting they were able to get that much positive caster with the stock suspension and bushings. Usually you need offset bushings or tubular arms to get to +5 on the caster.
 
I have another brother that I have yet to let into the driver's seat, so I was not going to let the tech drive it.
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That is just plain dumb. The tech has to drive the car before and after. I have seen a tech drive my car several times after by the book initial settings because it did not feel right going down the road. He kept tweaking until the car was dead nutz on. You can set up the front end by the book with “X” brand of tires and the car handles and drives nicely, change the tire brand, and the car handles like crap with the same settings.

What is your rear thrust angle?

I recently had a front tire snap a belt on my Duster and took it in to the shop my brother works at to get a pair of used tires swapped on and get the alignment done
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Did you install four tires of same size make and model, or have you mixed brands, on each axel? Used tires are less than a crap shoot, someone’s previous problem, and probably not the safest idea as tires have a shelf life of a few years in hot sunny climates, to five or six years in less sunny cooler areas of the country. Mixing tire brands by axel makes for strange handling for many reasons, a practice not recommended these days.
 
As a tech that does alignments I wouldn't find it the least bit strange if someone wanted to be present for the test drive of their car. That statement only applies to unusual cars. If someone with a 2006 camry/accord/stratus/generic car didn't trust me to drive it without them I probably wouldn't drive it with them either. I think the sportiest things I have ever aligned was a few honda s2000's.

Now another possibility is the alignment machine lied to you and the tech. We use a hunter laser rack and when making large camber and caster adjustments it has been known to show you numbers that are not physically possible. I have seen 6 degrees of camber on the front of a tundra. I had to restart the machine and run through the compensation procedure about 4 times just to get repeatable believeable specs on that truck. That truck was an involved pita that had its frame replaced.
 
Thank you for the input everyone. As far not letting the tech drive the car being dumb, you're welcome to your opinion. In order to properly wring it out and judge whether or not the alignment is going to work for this car, he would have to break the law on public roads to do it, not to mention that I'd have to trust him to handle it. This thing will break drag radials loose on a roll midway through 2nd gear. You'll forgive me if I have a problem with just tossing him the keys.
 
This thing will break drag radials loose on a roll midway through 2nd gear.
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So the car is on the perky side… So won’t most of the hemi powered Mopars, Corvettes, V8 mustangs & Camaros rolling off the showroom floor these days break out in second gear.

He won’t be power braking your car, and beating the piss out of it, he only needs to drive 35 to 50 mph steady speed for a mile or two to feel how the car reacts to curves, straight streches, and road crown. If you won't let the tech drive the car, you most likely won’t be happy with the alignment, because he can’t fine tune it.
 
This is a different experience than driving a modern car that's loaded up with electronic safety nets. I've had my fair share of alignments done on several different cars over the last 20 years. Not once has the tech told me that he needed to drive the car and, up until now, I have not had any problems with a car following an alignment.

I test drove the car myself the first time they did the alignment. It handled just fine under the conditions you describe. When I put it under power, the front tires squealed and it was extremely unstable.

The discussion about letting the tech drive aside, I was given access to the alignment rack on Saturday afternoon. There had to have been some problem with the rack the last day it was worked on because there was no way that they could have possibly gotten the figures they did. The caster was at +3.5 on the left and -0.8 on the right. We got the caster to +0.6 left and -0.2 right, low and behold, the pull is gone. Camber is right around -1.2 left and right. The car goes down the road straight, no squealing tires, and is now stable all around, though the steering is lighter than I would like, but it will have to do for now.

After poking around more closely, it looks like the strut rods are different from side to side. When I bought this car, I was told that the front end was completely rebuilt. The strut rod bushings on the rear side of the K member are cracking, but the front are pretty new, so I'm thinking the previous owner was full of crap. I'll be sourcing another strut rod and pulling down the entire front end in the coming weeks. :banghead:

Then we get to do this all over again...:thumbup:
 
The caster was at +3.5 on the left and -0.8 on the right. We got the caster to +0.6 left and -0.2 right, low and behold, the pull is gone
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That will do it. Was this the same tech working on Saturday that did the original alignment?

Just for the hell of it check the ride height per FSM. Installing problem solver upper control arm bushings will give you a degree or two more of caster which will give a bit more straight line stability.

I have a theory that your tech took the extra day to read up, or consulted an old timer on how to do an alignment on a Mopar.
 
72bluNblu said:
A lack of toe in won't eat tires.
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Absolutely and positively it will, just as too much toe will chew the outsides of the tires up. With too little toe, the insides of the tires are introduced too much to the road, likewise for the outsides of the tires with too much toe.
 
.8 is still a little too much cross caster, but if it goes straight congratulations on getting it fixed. Like I said in a previous post sometimes the machine will lie to you when making large adjustment. I like to do a complete restart all the way from the vehicle selection menu to see if my numbers stay the same or change. I have found that if you just redo the compensation without backing out all the way to the menu it doesn't always give accurate readings.

And I definately agree about a 12 sec muscle car requiring more driver skill than a modern car. Yes a hemi 300c has 350+ hp, but you cannot disable traction control and kick the backend sideways the way an overpowered 60's car will.
 
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