DIY toe alignment?

[lsxjunkie]

Alright racers, I'm sick of spending 80 bucks for a fancy Hunter toe adjustment and ending up with a car that pulls in the opposite direction, just to be charged again to get it back to where it was pulling less. I don't know how often shops get their machines calibrated, but it certainly isn't often enough.

Is there any trick to doing a string or toe plate alignment on an S197 on ramps? I can't get to my tie rods with the car on the ground so I'm going to have to drive it up on ramps. Also, I'm pretty positive my rear axle is off center, so I'm not really sure how to set the string distance if I want to do a string alignment. Thanks in advance.

 

[Ryan427]

Did the shop tell you your thrust angle was out? If your thrust angle is okay then then it's unlikely your rear axle is out unless something is bent. You should ask for a printout of the specs and see why it's pulling. It could be their machine is out of calibration but unlikely its out enough to cause a pull. Can you rotate the tires and see if the pull changes? Hunter alignment systems make doing an alignment so easy a monkey could do it.

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[2012 Boss 302]

Is the car actually pulling or is the steering wheel just off center?

You can use a tape measure to set toe. Just pick a spot on the front of the tires, and measure the distance. For example, the front measures 40 inches from center of the left tire to the center of the right tire. Now, take a measurement at the back of the front tires. Example, the rear of the front tire measures 40.25 inches from center to center. Add or subtract the difference. In this case there is 0.25 TOTAL TOE IN...


But FYI, toe does not pull, toe will make an off center steering wheel. Massive camber/caster difference or more likely a bad tire cause pulls.

 

[lsxjunkie]

I hit a series of nasty potholes that threw my toe way out. I put it on the Hunter rack at my local tire shop and showed Camber 1.3* L and 1.4* R. The Caster was like 6.9* R and 7.4* L. I set the toe to +1/32 on each side. After the alignment, the car tracked straight but the steering was heavier to the left. I decided to take it to a shop that considers alignments their bread and butter with another Hunter HawkEye machine. When I put it on the second rack, It showed the toe was -1/32 on the LF, 1/32 on the RF. I figured that was the issue and told them to set it to +1/32 on the driver's side again. Bad move.

The wheel self centers 5* to the left and pulls slightly left. This is obviously exacerbated by road crown, but I've checked it on a number of different road surfaces on highways that crown in both directions. I am sick of having to burn hours and money on getting my car to track straight and neutral.

I have Boss 302 takeoffs on my car. I can swap tires side to side, but not front to back. I have square snow tires that'll be going on next month that I might toss on the car this weekend just to see if it's the tires. But either way, I'd like to be able to physically measure the toe myself.

Thrust angle hovers between .001 and .004* out, depending on which rack I'm on. However, it looks to be 1/4" off when measured against the quarter panels. It's off enough that I don't want to use the rear hubs to try to square the suspension up.

 

[Mineral_01']

OP, check out both the Gunson trakrite and trakace. These items are a UK based company, but they are available to purchase on ebay and other places. Both items get remarkably high reviews. I have not found anything negative about then at all. Most people have said that they have found them to be more accurate than the technician (who doesn't give a sh!t) running a professional laser rack alignment. See video:

[video=youtube;dpBMrKmoS7E]http://www.youtube.com/watch?v=dpBMrKmoS7E[/video]


Also, please see my thread on S197 forums concerning alignments as well.
http://www.s197forum.com/forum/showthread.php?t=117211

 

[CSG]

Harder to turn should be castor and the "jacking effect". Pull is normally castor as well. Toe has to be pretty screwed up to pull on a perfectly flat road. I use a cheap Allstar toe setup with a longacre castor/camber.

 

[Tob]

Is there any trick to doing a string or toe plate alignment on an S197 on ramps? I can't get to my tie rods with the car on the ground so I'm going to have to drive it up on ramps. Also, I'm pretty positive my rear axle is off center, so I'm not really sure how to set the string distance if I want to do a string alignment. Thanks in advance.

I get the car up in the air on precut pieces of plank that are all screwed together. You can use pieces of 2 x 12, etc, that you can find in the lumber department at your local Home Depot or Lowes. I have four "stacks" made up of four lengths each. The ones I use for the front are stepped at the rear so that I can slide in a plank on a slope (creating a "ramp" if you will) and drive the car up and onto the top. I then remove those sloped pieces. I then jack the rear axle and slip a stack under each wheel. It might seem out of order but at this point I level the four blocks to each other (VCT floor tile works well if needed). Verify tire pressures. The vehicle is now up in the air, evenly, allowing easy access to the tie rods. Note in the following photo that the top pieces on my front blocks are actually solid Delrin. Delrin allows the wheels to turn pretty much bind free which makes adjustment a bit easier.

I'm using Maximum Motorsports' caster camber plates for strength and accuracy. I have a Longacre caster/camber gauge and I start with caster. The last alignment I did I set caster to approximately +7.5* on each side. Once caster is locked down I move on to camber and I use the same gauge. I like about -1.25* for the street and reasonable tire wear.


For toe, I start by having the wheel straight and immobilizing it. Note high tech equipment...

While I usually have stringlines setup when doing the camber (and straighten each wheel when check its respective camber setting) I take much more time to ensure accuracy when setting the toe. Chuck Schwynoch, the CEO from Maximum, recommended using conduit with equidistant hole centers for accuracy and repeatability. So I picked up two lengths of conduit, drilled them, and fit stringline through them. You could use fishing line, etc, but I have plenty of string from various construction jobs so that is what I use. I spaced the strings out so that I have room to turn the wheel without bumping them. I wire the conduit to jack stands that have been set so that their elevation is roughly at the wheel center. The plates you see running through the jacks allow me to pull the strings tight.

I then position the lines relative to the car. I do this by measuring perpendicular from the center of each wheel to the string, being careful to hold my stick rule level. Note that the rear axle width is wider than the "front." Your dimensions will be different between the front and the rear, but the fronts will mirror each other as will the rears. This takes a little time but once you are done you are good. Note - I had already set the rear axle where I wanted it via an adjustable panhard bar and squared up the LCA pickup points to the front K-member. I have Maximum's "Extreme Duty" rear LCA's and they allow adjustment if I need to move the axle fore or aft. You want your axle perpendicular to the longitudinal vehicle centerline or your thrust will be off.

I then set the toe by measuring at the horizontal wheel centerline, on the outside of the rim face (so that's one dimension at the front of the wheel and one dimension at the rear of the wheel), and adjust each respective tie rod until the wheels are parallel to the strings - then adjust for 1/16" of toe in, total.

This method takes a while. Lots of jacking when setting the caster or camber, followed by bouncing the suspension, etc. The more you do it the better you get at estimating how much a given adjustment at the plate will yield when measuring at the wheel. But once done, you are in a position to adjust the toe with relative ease. Accurately measuring properly set up lines results in a toe dimension that is absolutely perfect. I admit to getting quite a bit of satisfaction when I pull the car out of the shop and tear down the road with a wheel that is perfectly level and with the alignment numbers I specified providing me the performance I'm looking to get out of the car. Taking the time to set everything up properly definitely pays off.

To make things easier in the future I plan on picking up some turn plates and a different style caster/camber gauge. I like digital gauges for accuracy as well as getting away from any type of magnetic adapter so I'll probably pick up this setup from Longacre.

 

[lsxjunkie]

All the info.

Wow, awesome post. Thanks so much. Do you have any idea how I should square the strings up (or find the center of the car) if I am still using the factory PHB?

 

[Tob]

I squared the axle via the suspension pickup points. Once the front and rear were known to be in sync, I started the alignment. I assumed that the wheel hub faces were then square (which isn't necessarily correct) and then simply ensured that the lines were parallel to the axle centerline (both front and rear). I did not attempt to find a longitudinal center but rather split the difference in measurements (between the wheel center and the string) at both the front on each side as well as the rear on each side.

 

[lsxjunkie]

I squared the axle via the suspension pickup points. Once the front and rear were known to be in sync, I started the alignment. I assumed that the wheel hub faces were then square (which isn't necessarily correct) and then simply ensured that the lines were parallel to the axle centerline (both front and rear). I did not attempt to find a longitudinal center but rather split the difference in measurements (between the wheel center and the string) at both the front on each side as well as the rear on each side.

That makes sense. I can drop a plumb from the LCA mount and square up the strings using those and the front wheel center caps then.

I hope I have enough room in my garage to do all of this.

 

[Tob]

The rear LCA mount at the body. Then you can check to see how far off the axle faces are relative to the vehicle (at ride height if you are up on blocks all the way around) and not simply by measuring to the quarter panel.

I hope you have heat. I'm a bit west of you and it is starting to get cold!

 

[lsxjunkie]

At the body. And no heat. Hoodies and thermals and hot hot coffee.