Tires toe out as front end is raised
#2874596
01/15/21 04:07 AM
01/15/21 04:07 AM
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Joined: Jan 2003
Posts: 686 Houston, Texas
FastOrange
OP
mopar
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OP
mopar
Joined: Jan 2003
Posts: 686
Houston, Texas
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Slowly working through alignment issues, although I haven't had much spare time to work on the car. 1970 Challenger with mostly stock front end. Adjustable PST upper control arms and Strange D/A shocks. Aligned front end at resting ride height. Set caster at 3.2* Positive and zero toe. As the front end is raised, the tires toe out 11/16" at 3" rebound. Attempted to raise the outer ball joints by backing the caster back to 2.2* positive. Tires still toe out when raised. I looked at the Hotchkis website, where they sell some upper control "A" arms with a lowering bracket attached to the front of the upper control arm. Appears to me, that bracket will raise the outer ball joint by lowering the front of the upper A arm? Anyone have experience with these? Any other suggestions? Do they sell just the lowering brackets without the A arms? https://www.hotchkis.net/product/do...kis-1110u-a/?mk=&yr=&md=&sm=Ideas? Thanks Paul
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Re: Tires toe out as front end is raised
[Re: 375inStroke]
#2875594
01/17/21 03:41 PM
01/17/21 03:41 PM
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Joined: Jan 2003
Posts: 5,394 Pikes Peak Country
TC@HP2
master
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master
Joined: Jan 2003
Posts: 5,394
Pikes Peak Country
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Here is a quote from another thread about the process being used. Here is where I am at. 70 Challenger stock front end with Spc adjustable upper control arms. Drum brake car with Wilwood front brake conversion kit that retains the stock drum brake steering knuckle etc. FLAMING River Fast ratio manual box, but stock length pitman arm. Car used to be a power steering car. Idler and pitman arms are the stock length and are the same.. Car is set at stock ride height. Took the shocks off to assist with alignment. Centered the steering wheel travel in the middle. Its 3.3/4 turns lock to lock Set the Caster at +3.4* both sides CAMBER Close to 0. About .1 to .2 degrees positive Set the toe at ZERO at static height As I Jack up (rebound) the car in 1" increments The wheels toe out. The higher the car, the toe out increases. At 3" raised toe out is 11/16". I did measure the outer tie rods to the ground. There is a 1/8" difference between drivers side and pass side.. Options?????? Not sure what my options are to correct the bump steering? Book mentions bending the steering knuckles up and even. I thought I might start out with less caster, just to see how that measures out.. Thanks.
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Re: Tires toe out as front end is raised
[Re: TC@HP2]
#2875990
01/18/21 11:28 AM
01/18/21 11:28 AM
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Joined: Mar 2005
Posts: 1,547 Seattle, WA
375inStroke
Special needs person
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Special needs person
Joined: Mar 2005
Posts: 1,547
Seattle, WA
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There are more expensive tools you can buy, but you can make fixtures like this, and get a dial indicator for $20 from Harbor Freight. You get a flat plane of your favorite material, particle board, formica counter top, aluminum plate, and bolt it up like a wheel, with one inch marks on it. The dial indicator is on one end of another board, and a screw opposite it to track the board that's simulating the wheel. Place them about 26" apart, since that's the general size of the original tires that toe settings are based on. The hinge on the bottom is because the wheel moves in and out as it moves up and down, so the hinged board will follow the "wheel." Unload the torsion bar as much as possible, place a jack under the lower control arm, and raise it in one inch increments that you marked on the "wheel." The dial indicator will read directly how much toe change you're getting per inch of travel. To adjust bump steer, you need to raise or lower the pitman arm by shimming the steering box for the driver's side. For the passenger side, you elongate the idler arm mount bolt holes so you can raise or lower it. You then use a washer the size of the mounting bolt, and tack weld it in place to lock in your adjustment.
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Re: Tires toe out as front end is raised
[Re: 375inStroke]
#2876078
01/18/21 02:15 PM
01/18/21 02:15 PM
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Joined: Jan 2003
Posts: 686 Houston, Texas
FastOrange
OP
mopar
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OP
mopar
Joined: Jan 2003
Posts: 686
Houston, Texas
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Tires are on turntables and I'm using Quick Trick alignment tools for measurements. With the tires on turntables, I dont feel like there are any issues with my current measuring setup. I believe I'm getting accurate information and repeatability. According to my plot, the outer tie rods need to be raised. My current thinking has been, replace the tie rods with rod ends for more adjustability. Then spacers can be used as needed. Havent tried it yet though. I have not measured it in Jounce, since its more of a strip car. The torsion bars are installed and the ride height is set.. Thanks for the tips. If the rod ends dont give me the adjustability I need, then I will start over again. Thanks for all the great ideas!
Last edited by FastOrange; 01/18/21 02:17 PM.
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