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Stringless Wheel Alignment for DIYers.....

A few days ago, I completed the ride height adjustments and wheel alignment at home for a local Pelicanite. The tools and equipment used were typical handyman's tools available in most hardware stores. The goal of this post is to demonstrate that a DIY guy like many in this forum could perform 4-wheel alignment at your garage (home) using this simplified method. While the most popular and common method by Ray Scruggs use strings, I decided to go stringless. I've done this wheel alignment on my cars for over 10 years now and after the recent work with Mickey356's '83SC, I felt some people could benefit from this simple but accurate method.

I would say that I have invested less than $50 for the whole set-up. And very satisfied with the results that I have obtained from the car that I have done. The pictures below illustrate the 'special tools' built and designed by the author.




TOE Measurement:
Install the aluminum bar shown below on the wheel to me tested. Centering and leveling the bar position is the key for obtaining consistent and reliable data.


Hook up the leveling tool equipped with a laser beam. Position and align with the aluminum mounting bar. Next, turn the beam 'ON' to get the initial reading. For this demo, we are measuring the TOE of the rear passenger wheel as shown in the picture.


The projected laser beam produce a straight line (laser beam) more accurate than the conventional strings. Look very closely at the picture below. I call this gizmo as my 'distance gauge'. This measures the distance of the laser from the mounting base of the hub. This distance is referred to as Xp-f (passenger-front). Subsequently all the other wheels would have the following X (passenger-rear), (driver-front), and (driver-rear). These numbers might not mean a lot now but as I go along and explain the measurement procedures, these number are the most critical measurements needed for good alignment. I will explain as we proceed.

Take a good look at the distance gauge @ 15/16 mark. In reality, this red laser beam is very intense and bright, but my photography did not pick-up the color. The 15/16 mark signifies the orientation or position of the rear wheel with respect to the front wheel. And laser makes another mark at the front rod at the yellow tape.


The front rod is positioned so that the laser beam is on the yellow tape's marking. See picture below. The measuring rod should be secured and must not be disturbed during the whole process. Otherwise inconsistencies will occur.

Change the set-up for the laser bean and set it for the rearward direction. Clamp the tool on the mounting bar and begin to measure the other end. Position the rear measuring rod's yellow tape marking on the beam's projection. At this point you have completed half-way the test for the rear passenger wheel toe.

The PS-rear wheel has produced the front & rear data points. Now continue to the other side of the car for the driver side rear wheel toe measurement. Repeat the same procedure from the above for the DS rear wheel.



Following the same procedure as we did for the passenger rear wheel, the driver side laser beam would have also a 'distance from the front hub' as X d-f (driver-front). And the beam makes a red line on the front measuring rod some where at the graduated markings. See next picture.

Ignore the numbers on the tape measure. The tape measure (pieces) were both placed equidistant fromthe end of the rod (yellow tape). Since the locations of the markings on both rods are the same, we could use the relative difference from the numbers we get. And that difference is the TOE number. Whether it is negative or positive toe will be determined but the number we obtained during the measurement.

This is how we take the reading and will use Mickey356's data points.
PS-rear:
Xp-r = 15/16
front number = 0 (the yellow tape marking on the front rod)
rear number = 0 (the yellow tape marking on the rear rod).

DS-rear:
Xd-r = 15.5/16
front number = 4-6/16"
rear number = 4-9/16"

Ideally, you want the values of Xp-r and Xd-r to be equal or the same. But these numbers are close enough to be considered the same for our intend and purposes. Since the rear measurement is greater than the front measurement we have a negative toe or toe-in. The front and rear numbers were taken from the laser beam projections for the driverside rear wheel meaurement.

The difference between the front/rear numbers is -3/16" (-0.1875").This is the total toe number. So toe-in is measured as:
tangent theta =-0.1875/2/204=0.00046
Theta (angle) = -0.026.

The distance between the front & rear measuring rods is 17 feet or 204".

Doing the same procedures for the front wheels, I got the following data points.
DS-front:
Xd-f = 6.5
Front number = 0
Rear number = 0

PS-front:
Xp-f = 6.5
Front number = 2-3/16
Rear number = 3-1/16

Since the rear number is greater that the front we have toe-in (total) of -14/16 or a toe-in of -7/16" (-0.4375").

Tangent theta = 0.4375'/204" = 0.00214
Theta (angle) = -0.12 (toe-in)



Camber measurement:
Smart Racing has a very nice tool for measuring camber and caster. What I have is a McGiver camber tool that could detect as small as 1/32" deflection. A 1/16" accuracy is good enough to measure the changes in camber settings.




The biggest concern I have is how would people believe that the measurements are as good as the professional shops offer? I will get to that later. For the meantime, I would like to get some comment,suggestion, comment about this method. Thanks.

Tony

Last edited by boyt911sc; 12-22-2010 at 01:15 PM..
Old 12-21-2010, 10:17 PM
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Additional information........

After the ride height adjustment and wheel alignment were completed on Mickey356's car, I decided to bring the car to a couple of wheel alignment shops just to do the toe and camber measurements. No adjustment were done at the alignment shops. All they did was put the car on the lift and hook up their gadgets. Print the data and out from the shop.

Here are some pictures of the alignment shops.



My car at the falls after a hard day at the track.


After reviewing the printed data sheets and the numbers I obtained from my work, I could proudly announce that the numbers produced are as good as the professional shops offer if not better. Unfortunately, I don't have a tool to measure caster. But toe and camber are easily and accurately measured using this method or similar techniques.

Tony
Old 12-21-2010, 10:34 PM
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Very nice, Tony! Our local Pelican crew has also been working on a home, stringless system for toe. We've been using aluminum angle attached to the car (similar to what you've got), but with a vertical beam projected alongside the car. What this allows you to do is to take measurements with a tape/ruler using the beam the way you would a string. At this point the lasers are independent of the car, but the plan is to attach them to the rods to simplify setup.

FYI, we're doing this on leveling pads with scales (the not inexpensive part) and the lasers are easily leveled with built-in adjustment pads. For camber we're using a Longacre tool (also not inexpensive). The home alignment work is very satisfying (if not a bit exhausting) and we've had excellent results as proven on the race track.

Last edited by JP911; 12-21-2010 at 11:04 PM..
Old 12-21-2010, 10:41 PM
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you got a nice ride
Old 12-21-2010, 10:44 PM
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This is very interesting to me.
I have three cars that need competition alignments badly.


KT
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P.S. Here's a pic of the laser I'm using.

Old 12-21-2010, 11:05 PM
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Quote:
Originally Posted by trekkor View Post
This is very interesting to me.
I have three cars that need competition alignments badly.


KT
Would love to help, Trek. But at the moment I'm only versed in the method and desired settings for a 911. Learning a new car will likely require the better part of a day to get set up, although it's hard to imagine any car being as challenging to dial in as the rear of a 911 (for competition settings, that is).
Old 12-21-2010, 11:08 PM
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914 is super easy. Add/remove shims.

I want max negative camber and shim the other side to match.
I just to compare one side to the other.

Three degrees all around would be something...


KT
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Old 12-21-2010, 11:21 PM
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Instead of string & plumb line for camber, I use a digital level.
Old 12-21-2010, 11:41 PM
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Tony,

Great Job!! Hey, when are you going to let me cook you and your wife dinner? I'll PM you.

-Dan
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Old 12-22-2010, 05:23 AM
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Great job - I see in the pics the car is on a lift? I don't think the issue is with a "home aignment" or the accuracy per say - and not to use strings or to use strings or the homemade devices. The measurements are what they are and you can get very accurate with some clever, cheap setups.

The issue is making the adjustement (or getting to them with the car on the ground) which is near impossible on the ground.

The key is a setup where the car is elevated where you can make adjustments, on a level platform over and over without upsetting the initial settings.

This is where the issue is for the home mechanic - you can get around this with some plates for the front and creating an "aligment rack" but you need to factor this into the cost of the home alignment as from where I sit this is the biggest obstacle.

Anway - great post. I am redoing my suspension now and will need a full corner balance and alignment when done and was considering doing myself
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Old 12-22-2010, 06:11 AM
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It all about technique........

Quote:
Originally Posted by P-Dawger View Post
Great job - I see in the pics the car is on a lift? I don't think the issue is with a "home aignment" or the accuracy per say - and not to use strings or to use strings or the homemade devices. The measurements are what they are and you can get very accurate with some clever, cheap setups.

The issue is making the adjustement (or getting to them with the car on the ground) which is near impossible on the ground.

The key is a setup where the car is elevated where you can make adjustments, on a level platform over and over without upsetting the initial settings.


This is where the issue is for the home mechanic - you can get around this with some plates for the front and creating an "aligment rack" but you need to factor this into the cost of the home alignment as from where I sit this is the biggest obstacle.

Anway - great post. I am redoing my suspension now and will need a full corner balance and alignment when done and was considering doing myself

P-Dawger,

I agree with you that adjusting the rear wheels is the hardest part of the job. The front is a piece of cake. But I found a way (technique) of adjusting the rear (toe & camber) from one setting to another as small as 1/32" increment. The camber setting should be done first and the toe last. With the use of two (2) laser beams, you could move the line/s (laser beam) to where you wanted it go. So fine adjustment is done with some optical guidance.

But I disagree with you about making an adjustment without disturbing the initial setting!!!! Once you changed the setting (initial), it is altered. There's no way mechanical or others, to make some sort of adjustment and SAVED the old setting. Unless you have a computerized system (CNC)!!!! However, I could make the final setting back from the previous 'setting' very closed to the previous setting/s without difficulties. This was the closest thing I found in getting it set to the previous setting.

I will post some pictures of this procedure once I get away from doing some X'mas chores the wife wanted done. Happy holidays to everyone!!!!!

Tony
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technique

Tony,

Very well done indeed.

Tom
Old 12-22-2010, 08:32 AM
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Dinner date.........

Quote:
Originally Posted by da Vinci Dan View Post
Tony,

Great Job!! Hey, when are you going to let me cook you and your wife dinner? I'll PM you.

-Dan


Dan,

I read your PM before reading this post. I told my wife last summer about your offer. She was complaining about the enormous time and effort I spent in fixing somebody's cars for FREE. And I enjoyed every minute of it so I'm happy.

BTW, my wife picked December 27th (Monday) as our dinner date. I'll PM you with the details. How's the car running with the new clutch? Thanks.

Tony
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Terrific thread, Tony -- thank you so much! Got me thinking about how to adapt your custom tools to my needs.

Quick question for you; wondering if I understand correctly:

Quote:
Originally Posted by boyt911sc View Post

Since the rear number is greater that the front we have toe-in (total) of -14/16 or a toe-in of -7/17" (-0.4375").

Tangent thetha = 0.4375'/204" = 0.00214
Theta (angle) = -0.12 (toe-in)

Is there a reason that you measure and report total toe on the rear, but toe per side on the front? Is that some kind of standard that's implied or understood by alignment folks? Double-checking my math here; if total front toe-in is -14/16" (-7/8") = 0.875" then Theta (angle) = -0.25 (total toe-in). Did I do that right?

Thanks again for an awesome thread.

Dale
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Old 12-22-2010, 09:20 AM
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I've been remiss in my Pelican duties (very busy time of year for me) so I missed this post yesterday.

Anyway, I can attest first hand to Tony's ingenuity and skill. It's my car in the pics and the car is perfect. I'm not much of a "mechanic" so I can't contribute to the alignment procedures and adjustments, but what ever he did he did it right (and he even dropped the car off to me). He's a sharp guy. My brain no wurk so gud like hims duz
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Old 12-22-2010, 09:23 AM
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"Unfortunately, I don't have a tool to measure caster."

Caster is proportional to camber change vs steering angle.
There is a simple method to measure caster. It has been about 10 years since I have done it, but it is something like measure the camber change over a 20degree rotation of the wheels then subtract the camber 20 degrees in the opposite rotation. Multiply times 1.5 . Verify as this is from my often bad memory....

PS: I just taught my 2 boys how to adjust toe in last Sunday; they loved it.
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Old 12-22-2010, 10:39 AM
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I have managed to do caster and camber using nothing more than a digital level with a magnetic base. $60 at home depot. Its accurate to 1/10 of a degree...

You can do caster by placing the level onto the front of the strut, and you will get a degree reading. I have used this method for cars that "pull" to one side, and once the readings were equalized, the car ran true...

You can also apply the level to the outside of the wheel (up/down) to get a degree reading for camber. Works great as long as the ground is flat (zero out the level at 0.0 degrees).

Toe, I haven't found a simple way to do...
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Correction.........

Quote:
Originally Posted by Flat Six View Post
Terrific thread, Tony -- thank you so much! Got me thinking about how to adapt your custom tools to my needs.

Quick question for you; wondering if I understand correctly:




Is there a reason that you measure and report total toe on the rear, but toe per side on the front? Is that some kind of standard that's implied or understood by alignment folks? Double-checking my math here; if total front toe-in is -14/16" (-7/8") = 0.875" then Theta (angle) = -0.25 (total toe-in). Did I do that right?

Thanks again for an awesome thread.

Dale


Dale,

Thanks for noticing the calculations.You did the correct calculation but -14/16" is the total toe number. It should be divided by 2 to represent the toe for one side. I made the correction to show the right value.

Calculated angle (toe-in) = 0.125 degrees

Generally, the toe value represents one side of the car. But the printed computer data from alignment shops provide two numbers. Total toe and toe values in degrees.

Tony
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