Front suspension suggestions for better tracking

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jcolman

jcolman

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Once again I turn to the wisdom of you guys with years of experience.

I finally have my car *almost* the way I want it. I swapped out the auto for a Tremec TKX 5 speed, I have a new rear end with a powr-lock differential and Hotchkiss subframe connectors. Previously, I had added Borgeson power steering. The car handles really well now but the tracking could be better. My shop gave me as much positve caster as they could, about 3.5 degrees.
What would be the next step to help improve drivability? I have Q1A adjustable upper A arms but the rest of my front suspension is stock. Stock torsion bars, stock anti-sway bar, poly bushings, good shocks.

Would adjustable strut rods be my next step to help increase caster?
 
Explain the “tracking” issue in a little more detail.

Is this when going straight down road and car wonders or hunts?

is this when transitioning into and out of a turn?
 
autoxcuda said:
Explain the “tracking” issue in a little more detail.

Is this when going straight down road and car wonders or hunts?

is this when transitioning into and out of a turn?
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Mostly when going straight. The car likes to wander a bit.
 
jcolman said:
Mostly when going straight. The car likes to wander a bit.
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You could try adjustable strut rods and see if 5.5 degrees of positive caster helps.

other than that, factors would be: your tires, other alignment specs -camber/toe, rear end alignment (shown on your computer 4-wheel alignment sheet), or worn suspension components.

I don’t think shock or increasing roll stiffness is going to do anything for wondering at static cruise speed… cause the car is just going down the road straight.
 
Are all the components you didn’t mention new? Ball joints, tie rod ends, idler arm? The idler arm by itself can cause wander.
 
autoxcuda said:
You could try adjustable strut rods and see if 5.5 degrees of positive caster helps.

other than that, factors would be: your tires, other alignment specs -camber/toe, rear end alignment (shown on your computer 4-wheel alignment sheet), or worn suspension components.

I don’t think shock or increasing roll stiffness is going to do anything for wondering at static cruise speed… cause the car is just going down the road straight.
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Thanks. The tires are new. I should add that I have 18" wheels, 6" front 8" rear. My rear springs are super stock. All other suspension components seem to be in good condition. One other thing I forgot to mention, is that the spindles seem to be a bit short. The technician had to add a washer to the nut in order to tighten it down.
 
mvh said:
Are all the components you didn’t mention new? Ball joints, tie rod ends, idler arm? The idler arm by itself can cause wander.
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The idler arm appears to be in good condition. All other components seem to be good as well however I suppose I should have them throughly checked out before doing anything else.
 
jcolman said:
Thanks. The tires are new. I should add that I have 18" wheels, 6" front 8" rear. My rear springs are super stock. All other suspension components seem to be in good condition.
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Low profile tires are helping the situation. IIRC, they aren’t super low profile…. Sizes?

Alignment sheet showing rear end measurements?
 
autoxcuda said:
Low profile tires are helping the situation. IIRC, they aren’t super low profile…. Sizes?

Alignment sheet showing rear end measurements?
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Front Tires: 235/40 ZR/18. Rear Tires: 245/50/ZR18. The last alignment showed rear at 0.0 camber, -0.13 toe on left rear. Right rear -0.1 camber, -0.18 toe. Total toe 0.31. Thrust angle 0.02.
 
Front tires are awful low profile. Just magnifies situation.
 
jcolman said:
I suppose so but I'm not going to change them.
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try more caster, check suspension (especially idler)

… maybe shocks like a simple Bilstein RCD will give you some better “feel”. But won’t directly change steering wheel wondering

it’s a tough thing to diagnose over Internet.
 
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Bergman Autocraft. a vendor on this forum makes adjustable upper control arms ...just an option Im sayin
 
Is it really wondering or following grooves in the road. Tires with short sidewalls will do that. Mine do it on some road but is fine on others. I had a fox body mustand in the early 2000s and that was the first car I had with low profile tires. It was horrible at following the grooves in the road.
 
jcolman said:
Front Tires: 235/40 ZR/18. Rear Tires: 245/50/ZR18. The last alignment showed rear at 0.0 camber, -0.13 toe on left rear. Right rear -0.1 camber, -0.18 toe. Total toe 0.31. Thrust angle 0.02.
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And +3.5° of caster?

0 camber isn't helping, a little bit of negative camber will help keep the car heading straight. If you could get a -.5° camber that might help some. I'm a little surprised you could only get +3.5° caster with the QA1's, but you're not the only one that hasn't been able to get a ton of positive caster with them. 235's aren't overly wide, tracking issues usually become more apparent with wider front tires. But I like to run more caster than that. Granted, I have 275/35/18's on mine, but I run +6.5° of caster on my car. That keeps it nice and stable and straight ahead. I've run it with as little as +3.5° and as much as +8°, and with 275's and my ride height and suspension around +6.5° was the sweet spot between the car being nice and stable and it not adding a TON of steering effort. Past +6.5° makes it exponentially harder to steer. Less than +6° and it would start to track around a little more. But again, that's with 275's not 235's.

Before I bought anything I'd see if you can add a little negative camber without sacrificing a ton of caster. The caster is ultimately more important, but that zero camber thing might be hurting you more at the moment. Even -.25° would be better.

I run Bergman AutoCraft SPC UCA's on mine though. You definitely won't get to +6° with the non adjustable QA1's.
 
72bluNblu said:
And +3.5° of caster?

0 camber isn't helping, a little bit of negative camber will help keep the car heading straight. If you could get a -.5° camber that might help some. I'm a little surprised you could only get +3.5° caster with the QA1's, but you're not the only one that hasn't been able to get a ton of positive caster with them. 235's aren't overly wide, tracking issues usually become more apparent with wider front tires. But I like to run more caster than that. Granted, I have 275/35/18's on mine, but I run +6.5° of caster on my car. That keeps it nice and stable and straight ahead. I've run it with as little as +3.5° and as much as +8°, and with 275's and my ride height and suspension around +6.5° was the sweet spot between the car being nice and stable and it not adding a TON of steering effort. Past +6.5° makes it exponentially harder to steer. Less than +6° and it would start to track around a little more. But again, that's with 275's not 235's.

Before I bought anything I'd see if you can add a little negative camber without sacrificing a ton of caster. The caster is ultimately more important, but that zero camber thing might be hurting you more at the moment. Even -.25° would be better.

I run Bergman AutoCraft SPC UCA's on mine though. You definitely won't get to +6° with the non adjustable QA1's.
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Those are his rear alignment measurements.

I wanted to check if anything was weird back there. Super stock springs should make one side of rear higher than other. Buddy has two A-body MP sets bought 8 or so years apart. They gave different results.
 
autoxcuda said:
Those are his rear alignment measurements.

I wanted to check if anything was weird back there. Super stock springs should make one side of rear higher than other. Buddy has two A-body MP sets bought 8 or so years apart. They gave different results.
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Oops, should have read closer.

Well, what are the rest of the front alignment specs? +3.5° isn't a ton, but 235's aren't crazy wide either.

jcolman said:
Thanks. The tires are new. I should add that I have 18" wheels, 6" front 8" rear. My rear springs are super stock. All other suspension components seem to be in good condition. One other thing I forgot to mention, is that the spindles seem to be a bit short. The technician had to add a washer to the nut in order to tighten it down.
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Wait, added a washer where? Under the ball joint or under the spindle nut?
 
jcolman said:
............... the spindles seem to be a bit short. The technician had to add a washer to the nut in order to tighten it down.
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MAYBE unrelated, but STOP THERE AND FIND OUT WHY? Something.........wrong bearing combo? Something worn in a hub. Oddball hubs, some "conversion?" THIS SHOULD NOT EVER BE NEEDED

Years ago I looked at a truck for a guy, one spindle had been replaced. Turns out there is a "light" and "heavy" duty, and he ended up with one of each, and the TOO LARGER INNER BEARING bore was slopping around on the back side causing problems. Had to "fix" it all over again---go out and find a correct one.
 
67Dart273 said:
MAYBE unrelated, but STOP THERE AND FIND OUT WHY? Something.........wrong bearing combo? Something worn in a hub. Oddball hubs, some "conversion?" THIS SHOULD NOT EVER BE NEEDED

Years ago I looked at a truck for a guy, one spindle had been replaced. Turns out there is a "light" and "heavy" duty, and he ended up with one of each, and the TOO LARGER INNER BEARING bore was slopping around on the back side causing problems. Had to "fix" it all over again---go out and find a correct one.
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You are right....I need to make sure that I have the correct spindles. The technician mentioned that he had to put a washer on the botton nut after the recent alignment and I totally forgot about it. Obviously I need to start there before I do anything else. I guess I was thinking that maybe there was some variances in tolerances.
 
Also I would not even consider mods of any kind, not even strut rods, until you have fully ruled out
cracked members flexing
Anything loose, including steering box, and ESPECIALLY play in the idler, pitman, and box, and any other ball joint or tie end. Check ball joints and bushings. The procedure in the service manual is fairly good, go to MyMopar if you don't have one. You must get the weight ON the bottom arm to check the lower joints.

So far as the washers, I've seen hubs "eat" pockets that allow bearing cup slop. Unless it is some wrong combo of parts or damage such as that you should NEVER need such a thing. Check the bearings carefully (cones) for fit on the spindle, check for play in the cups in the hubs. Only "mod" I could think would cause that is if the internal bore of the hub got damage and someone turned it deeper trying to fix it. That would completely change the hub/ wheel offset on the spindle, no matter how little. Keep a juandiced eye at it
 
jcolman said:
You are right....I need to make sure that I have the correct spindles. The technician mentioned that he had to put a washer on the botton nut after the recent alignment and I totally forgot about it. Obviously I need to start there before I do anything else. I guess I was thinking that maybe there was some variances in tolerances.
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Sounds like a washer on the Lower or Upper ball joint nut to Spindle taper hole. The ball joints seem to come with washers for that now. I think the threads in the ball joint aren't cut deep enough and/or spindle thickness varies. If so, it not a deal breaker.
 
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72bluNblu said:
Oops, should have read closer.

Well, what are the rest of the front alignment specs? +3.5° isn't a ton, but 235's aren't crazy wide either.



Wait, added a washer where? Under the ball joint or under the spindle nut?
Click to expand...
I think he said it was under the spindle nut.
 
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