66 Dart GT is Wandering

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Can someone help me with this problem. My 66 Dart GT wanders side to side. I installed a rebuilt power steering box from Rock Auto, had the car in the alignment shop, and inspected and made sure the torsion bars are installed correctly. The car has not been in a wreck, and the front end has all new parts including bushings on the sway bars. I am puzzled since the car still wanders left to right, and it is difficult to drive. Someone suggested that a limited slip differential can sometime switch back and forth from one side to the other making the car want to wander. Do any of our members have any other ideas? The tires are properly inflated on the old style SS Cragers. Large investment in a car that is a struggle to drive. Thanks for the help and the suggestions. Pulling my hair out on this one, and I do not have a lot to spare. Through our forum, or PM me at Old Dart 66. Thanks again.


Just an update. Still have not found the problem. I checked the toe-in and the camber which are correct. Next step is to change out the tires. I will see how that goes. I thank all who have discussed possible approaches to solving this problem. I will post the solution, once it is found. Thanks again. Old Dart 66.
 
if all the suspension bushings were replaced and the drag link that would leave some other problem other than the bushings and drag link. the only thing I can think of would be cracks in the K frame where the lower control arm mounts to it. Possible loose wheel bearings but I would assume that was checked. Usually the culprit is the strut rod bushings or the lower control arm bushings. I have also seen cracks in the K frame where the steering box mounts to the K frame. alot of guys beef up these areas of the K to eliminate any flexing, especially on the pre 67 cars.
 
I'm still a newbie when it comes to being a mechanic, but is it possible one of the brakes is grabbing and letting go intermittently?
 
"Assuming" the front end is tight, nothing broke, aligned correctly, etc, THERE ARE many things that can "gotcha"

One, very simple, is mismatched tires front to rear. I'm sure everyone is aware of the dangers of mixing bias and radials, but mixing front / rear, certain combos of different radials can cause handing problems

Also look to problems in the rear.........loose shackles / bushings / spring eyes, and so on.

I don't see limited slip causing big problems on a straight road unless the rear tires are mis-matched. I rebuilt the Ferd 9" in mine, and got it "too tight." I figured it would settle in, but never did. It is so tight that just easy pulling out of a drive in / parking lot will "skootch" the rear tires or squeal them. It drives just fine. It is, however, immediately obvious on a hard 1-2 shift that it IS limited slip.

Back to the front end..........front tire wear CAN cause wandering. Beg borrow or steal different tires, or if you run same on all 4's rotate them

Don't take an alignment shop at their word, learn to check things yourself. Get under there with a friend, have him / her turn the steering wheel a small amount and look for movement, such as play in "anything" that should not be there, and up/ down movement of the idler. Also look for unwanted movement in the bearing for the pitman shaft, and for play in the column shaft / coupler / box spline.
 
Thanks for the advice from our FABO members. Great advice, and I will look into these possibilities. I do have 4 good, matched radials, where the tires on the car are checked and old. The car has been sitting on these tires for the past seven years, and the front and the back are not matched. All of the front end and rear end parts are new and torqued to factory specs. I did not notice any cracks in the K-frame while I was restoring the car. I will change the tires out, and post my results. If any one else can give me any other advice, I would surely appreciate it. I do thank: 67Dart273, Peyote, and Omahamoparguy for their almost immediate responses. Thanks to all our members who helped me in my restoration.

Old Dart 66
 
"ALL" new parts?
Ball Joints upper and lower
control arm bushings upper and lower
tie rod ends inner and outer
pitman arm and idler arm
strut rod bushings
sway bar links or bushings

Not that all these need to be replaced but that is a fairly complete list.
On later models it is common for the sleeves that the lower control arm shafts mount into to break loose in the K member.
Also the wheel bearings are something to keep tabs on...
 
..you have no 'toe in' you need 1/16" - 1/8"
..or you have no caster.You need to lay the top ball joint back a couple of degrees so the front end self centres at speed.
..camber should be within a degree of vertical
fire your alignment guy.
 
Caster makes it drive straight and toe out will make it wander. I would imagine it has been aligned. Hopefully someone will chime in with some alignment specs. Most of the specs that come from modern alignment machines don't make it drive right. I would put on some new tires for sure. You need to replace them anyway. Never overlook the obvious.
 
Old Dart 66 said:
I installed a rebuilt power steering box from Rock Auto,
Click to expand...

Jerry - this might be the problem. "Rebuilt" parts have a bad track record for not being done right. If it is the box, have Firm Feel or that company out west rebuild it and maybe go to a Stage 2 or 3 - gives you a modern day feeling. Just a thought.
 
Let's simplify this with a couple of questions.

Does it have play in the steering when turned off and sitting still.
(How much can you turn the wheel back and forth without moving a wheel?)
You will not be trying to turn the wheels but just the steering wheel until you hit resistance.

Does it seemingly change direction with NO movement of the steering wheel, or does it try to move the wheel when it wanders?

We can narrow things down quite a bit with these two answers.
 
The number one go-to for wandering after an alignment is the tires.
You know what a caster wheel is right? Well if your front tires are worn just a bit more on one side than on the other, then they sorta become very large caster-wheels, and that means they like to follow the road. In the pre-radial days this was easy to prove by pumping up the tire pressures. Radials don't respond the same way. That's one of the reasons we used to rotate our tires at every second oil change/ 6000 miles, to prevent tire wear from becoming established. For your car with radials assumed the most likely cure is to put the rears on the front and see how it goes. If the wander persists you will have to replace at least two of them to go onto the front.
Now I need to tell you something else. There is a thing called "scrub radius" The factory minimizes the effect of it by installing rims with a favorable center offset, which we commonly refer to as backspace. If the center of your front wheels are in a different place,or if the tire roll-out (diameter x pi or 3.1416), is different from the factory tire, than the scrub radius can start to steer the car. So think about that before you buy new tires. Our A-bodies are pretty good about that, because it's hard to put a too-tall, or too-wide tire up front. But it can be done. For instance, a 15 x 8 wheel with a zero-offset(4.5 backspace) can be installed with about a 24 inch tall tire, that would run just fine;cuz the parameters match the factory set-up. However that same 15 x 8 wheel with a 3 inch backspace and a 26 inch tall tire could make the car wander, by reason of increasing the scrub-radius to nearly double the factory spec. So that's something to keep in mind.
 
TrailBeast said:
Let's simplify this with a couple of questions.

Does it have play in the steering when turned off and sitting still.
(How much can you turn the wheel back and forth without moving a wheel?)
You will not be trying to turn the wheels but just the steering wheel until you hit resistance.

Does it seemingly change direction with NO movement of the steering wheel, or does it try to move the wheel when it wanders?

We can narrow things down quite a bit with these two answers.
Click to expand...
Be aware that there will naturally be some play in a power steering box setting still. But I agree..... answers to Trailbeast's question above will help a lot.

Be aware that the allignment specs of these early and mid 60's Mopars, had very little caster. This made the car light to steer for the ladies, but it will not feel like a modern car's steering (that has distinct centering feedback on the steering wheel, that increases the more you turn the wheel). The steering will normally be very light, and many people have a lot of trouble adjusting to this who never drove them 'back in the day'. We tend to unconsciously judge our steering angle partly from the steering feedback, and when that goes missing with an old steering system alignment, drivers tend to saw back and forth a tiny amount on the wheel, trying to find the feedback that is not there, and the steering seems to be erratic but it really is the driver.

The classic solution to this is to put in added positive caster, as mentioned. And if the alignment shop put in manual steering caster, which was 0 to -1 degree, then with power steering it will be REEEEALLY vague.

Did you get an alignment report from the shop? And did you install the new front end parts? Would you be willing to share the list of the parts installed?
 
Old Dart 66 said:
The car has been sitting on these tires for the past seven years, and the front and the back are not matched.
Old Dart 66
Click to expand...

Tires that are seven years old are probably separating. Look at the treads and see if they are wavy.
 
You're right to get new tires, for handling and safety. Be careful getting 'bargain' tires. A lot of these are old stock. Tires deteriorate with age. Learn to read date codes on tires and make sure you're getting NEW tires.

AJ/FormS is right about greater scrub radius (from the Cragers backspacing) making steering 'hunt'. How did the car drive on Cragers before the suspension rebuild?

IT IS ESSENTIAL that an A-Body has as much caster dialed in as camber adjustment will allow (the two are off the same adjusters). Radial tires have less 'trail' than bias plys, so more caster has to compensate. Forget old specs; get close to 2 degrees.

BUT: Often new strut-rod bushings (thicker lengthwise than stock bushings) push the lower control arm rearward, killing caster. Compare your new bushings against somebody's stock ones. If that's the issue, you've got to fix that first to get caster.
 
66
There is a lot of info here,confirmed from post to post, so I thought I'd recap it here, cuz a wandering car is no pleasure to drive--for sure.
So as mentioned, there are several things you can do to minimize wandering;
Tires,Scrub-radius,Caster, Steering box,Chassis flex, Alignment Thrust angle, Bump-steer and ride-height,shocks,Toe, Adjustments for radial tires.

-Tires and scrub radius was in post 13
-Caster in 7,14,16, and I'd like to add that the Moog offset UCA bushings are pretty cool, and a real boon for our A's, and well worth putting in even if it means pulling out brand new stockers out, and a realignment. More money I know, but until you get the caster to around 2plus degrees, the car, on radials, will always require some near continuous correction on any but the flattest smoothest hi-ways. And someone mentioned the strut-rod bushings. These guys locate the LCA in the fore/aft plain. The fatter they are on the backside, the harder it will be to get decent caster. If they get to be too thin, they can suck the LCA pretty far forward and put a lot of strain on the LCA bushings. But above all, they have got to be tight.
-Steering box in 9,12 and I'd like to add that The sector shaft adjustment is critical, in that if it is too tight the car will tend to drive in whatever direction it was last pointed, making constant corrections mandatory. If too loose, well that introduces a bit of wiggle in the straight ahead steering which gives a somewhat vague feedback to the driver, but it is still preferred over too tight. Somewhere in between is the perfect adjustment. This IMO has to be fine tuned by you,the operator, cuz most techs will never get it right. Adjusting it does not affect the alignment. And lastly, Chrysler boxes have to be set up to not self steer, by adjusting the control valve on top of the box.
-Chassis flex in 2,4,6, and I gotta add rust-through of the aprons to the firewall, or aprons to the frame. The front stub frames are supported by those aprons, making them part of the Unibody. If the unibody flexs wandering cannot be controlled.
-Thrust angle. This used to be called dog-tracking, or doing the Nova-crawl. This is caused by one side of the car having a longer wheelbase than the other(and in Darts is somewhat common. Minor dog-tracking is not a big deal, as far as wandering is concerned. But if it gets to the point that the steering has to be turned a bit too far, that the sector shaft clearance on center gets taken up, well then the car will again tend to steer in whatever direction it was last pointed.
-Bump-steer and ride height.The factory specifies a ride height. This is to put all the steering parts in a position to minimize wander that is introduced by the vertical movements of the various parts that cause them to self-steer. If you change the ride height, you sometimes introduce significant bump-steer that is felt by the driver as wandering.
-Shocks. These have a minor effect, as they need to control the movement of the chassis to prevent the aforementioned bump-steer. If one is stiffer, or one is worn out, well you get it, bumpsteer/wander.
-Toe was mentioned several times.Toe is only right in a very narrow window. And the window is ever-changing.This spec is is meant to compensate for the flex in the steering parts and for the play in the various joints.When it gets outside this spec.bad things happen. With too much toe-out, the tires tend to follow every little rut in the road, which the driver interprets as wander.With too much toe-in the tires can wear pretty fast, and wander is perceived, but less so than too much toe-out. The target is ever-changing cuz the parts are ever wearing. I find that this spec while targeted pretty close by the tech.,will occasionally still need to be fine tuned in the field. I've had many vehicles on the rack that did not respond to any setting given in the spec book. For these the only cure is roadtest and field adjustment. Then back onto the rack to see what worked. Then a memo onto the workorder, a copy of which stays in the machine for next time.
-Adjustment for radial tires mentioned in 8,14,16, and I'd like to add for customers with wandering complaints, I would align the vehicle with sandbags in the front seats to compensate for the weights of the driver and passenger. Some suspensions sag so bad that that the ride height is all wrong after the driver gets in, and my settings,tho perfect, were absolutely no good. So if your car has skinny bars, sandbags may be required. (one time I aligned a small FWD car , and it kept coming back. Finally I found out that the driver was 300plus pounds. Well there was no compensating for that. He needed a different car!) Then Caster/camber. Since Our A's use the upper CAs to adjust these together, it's always a balancing act to trade one against the other to get a satisfactory number. This is where those Moogs come in, and the strutrod bushings. With the extra Caster that these provide it's usually no problem to get some good numbers. The key is to get both sides the same. What I do is to set both sides to Zero camber,Zero toe,and max caster for that Zero. This shows me which side of the car is Caster-limited. Then I set that side first, knowing that I can match the otherside to it. For a city car I make both sides the same. If a guy spends a lot of time on the open hiway where the roadway is crowned, up to 1/2 degree of extra caster on the passenger side can help or eliminate a crown-induced pull,reducing driver correction and fatigue.
- The specs; On my 68 Barracuda I have found the following satisfactory; Caster of 3* and both sides the same, Camber of Neg. .5 *(+/- .2*),Toe was field adjusted, Ride height of 6.0" (+/- .5) from the lowest point of the K on the vehicle centerline, with up to about 3/8 inch front down-rake as measured at the front/rear of the rockers. The bump steer was corrected to be nearly zero for the ride-height in a range of about 3 inches.At these numbers tire wear is a non-issue, Straight ahead driving is a dream, and handling is fun with the 1.03 bars ,good shocks, and a big swaybar. And yes I tried several different front wheel offsets and several different tire widths and several different tire heights. That's how I bugged out the scrub radius thing. That's how important that little spec is. At the time I was a seasoned alignment tech, and had free-access to the rack, after hours. I will not tell you how many alignments I gave it over the course of two summers. It was crazy I tell you. I can tell you this; street specs are not the same as autocross specs!, and the wider your front tires are, the flatter they need to run, and the more important the Scrub-radius becomes. Shoot for the max caster for 1/2* neg.camber, and both sides the same, with sandbags; and she will be pretty close. Be prepared to field adjust the toe, sometimes as little as a quarter turn. Keep extremely accurate notes on which side you adjusted which way, cuz without the notes I guarantee you will get lost. Mark the sleeves!
-Guys, sorry if I missed giving credit where it was due.OP theres no bad info in this thread. And since you are getting new tires, your troubles may be over. This recap is more for those who come after, and use the search feature.
 
You might remember my question about my wandering issue on my 66 Dart GT. I would like to thank all of you who contributed advise on solving my problem. As I said, everything was new in parts from front to back. We had suggestions of tire separation, scrub radius, alignment, mis-matched tires and etc. All of this input was great advice. This was a thread which I started last fall. After spending the winter pondering the issue, I brought the car home this spring and dis-assembled most everything which I put in new. When I installed everything last year...all brand new, I made sure that all brake lines were clear. It turns out that, despite being new, the rubber brake line which feeds the distribution block mounted on the rear axle, had collapsed, and I was having brake drag on the rear wheels which caused the car to move from side to side. I thank all of you who helped me with this issue. Now resolved. Buy American.
 
Old Dart 66 said:
You might remember my question about my wandering issue on my 66 Dart GT. I would like to thank all of you who contributed advise on solving my problem. As I said, everything was new in parts from front to back. We had suggestions of tire separation, scrub radius, alignment, mis-matched tires and etc. All of this input was great advice. This was a thread which I started last fall. After spending the winter pondering the issue, I brought the car home this spring and dis-assembled most everything which I put in new. When I installed everything last year...all brand new, I made sure that all brake lines were clear. It turns out that, despite being new, the rubber brake line which feeds the distribution block mounted on the rear axle, had collapsed, and I was having brake drag on the rear wheels which caused the car to move from side to side. I thank all of you who helped me with this issue. Now resolved. Buy American.
Click to expand...


Ha! I nailed it with a lucky guess! LOL
 
ir3333 said:
..you have no 'toe in' you need 1/16" - 1/8"
..or you have no caster.You need to lay the top ball joint back a couple of degrees so the front end self centres at speed.
..camber should be within a degree of vertical
fire your alignment guy.
Click to expand...

Read this ^^^^^^ over and over. End of story.
 
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