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> How to correct "toe in/out" using the string techy, Write up w/vid(not mines) on how to correct/measure toe in/out
post Aug 29, 2011 - 8:09 PM
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808celica



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***I am not responsible if your alignment is messed up because of you attempted to correct your toe angle****
Attempt at your own risk laugh.gif

HowTo: 4 wheel alignment (toe and thrust angle)
This is intended to describe the process of doing a 4-wheel alignment on your car using the "Strings" method. This will allow you to set the toe on all 4 wheels individually and with respect to the chassis centerline. This means your Thrust Angle should be correct when finished.

This article does NOT cover adjustment of camber or caster. It will be assumed that your caster and camber adjustments are correct and equal or close to. This write-up also assumes that your car is square and true. Meaning it's not bent, twisted, or damaged in any way.

If your chassis is straight, this document will guide you through the process on doing a four wheel toe and thrust angle correction. You can also use this if you already had an alignment done and 6 months down the road you want to see if your alignment has changed. Then you can use this document to re-correct your alignment given you have a specs written down when alignment was done professionally.



Background

Toe is something you should re-adjust after every other alignment change. If you adjust camber, re-adjust your toe. If you adjust caster, re-adjust your toe. Additionally, anytime you unbolt something in your suspension linkage (strut, control arm, etc) you should consider at least checking your toe to make sure it's still dead-on. In my experience, no other factor has led to more handling irregularities than incorrect toe. It has a significant impact on the way your car takes corners, tracks a straight line, how fast your tires go bald, etc. Toe-in is just as likely to cause a wandering front-end as toe-out, depending on the surface you're traveling on.

Likewise, having a thrust angle that is not 0 will make your car take left corners differently from right corners and even makes the vehicle present a lopsided aerodynamic profile to headwind while you're bookin' down the interstate. As you can see, Toe is important. To define "Toe" and "Thrust Angle", see whatthe's post here in part 7 :The Ultimate Guide to Suspension


Estimated Time for completion

-2 hours or more your first time
-45 minutes with experience, not including setup and cleanup


Tools and supplies:

-(4) jackstands
-a jack
-Bright colored string or heavy fluorescent monofilament fishing line
-a short ruler that reads in very small increments of inches (1/32" or better) or mm for our overseas people. (I have used metric)
-17mm 19mm 12mm 14mm Open-end wrenches
or a Crescent Wrench Medium, Small, and Large
-Slip plates, Floor Tiles to put under wheels to make centering the wheels easier
-leveling tool

Measurement Procedure

The first step is a test drive, you are looking for a couple things. Namely, does the car wander? Does it take left corners differently from right corners? Is your steering wheel off-center? Do you have to forcibly hold it off-center to travel in a straight line? Take note of all of this and more if you can. I really emphasize do take NOTES. In fact, your success in this home-alignment will depend heavily on your ability to document the characteristics and relate them to the measurements you take.

Next step is to park your car on a nice flat, level smooth surface. If you have slip-plates/floor tile, park on the plates. The key here is to make sure your steering wheel is exactly centered as you are driving in and that you don't touch it at all once you stop moving the car. Ideally, you line the car up then center the steering wheel exactly, hold it while rolling forward another foot or two, then take your hands off it and never touch it after that until you're ready for your test drive. If your garage floor is not perfectly level, you can use thin parquet floor tiles to build up one side to get the car perfectly level.

Now it is time to setup your measurement rig. This will consist of your four jackstands and the strings. Roughly place the front ones about 4" from the fender just in front of the front tire. Likewise, place the rear ones roughly 4" from the fender just behind the rear tire.

Now, tie a loop in the end of the string and loop it over the top of your jack stand. Run the string to the other jackstand and tie another loop to hold it on. Now pull the jackstands apart abit so that the string is nice and tight. Raise each jackstand so that the string is at the same height as the centercap on your wheels.

From here, we you have to make everything perfect. We need to use a very finely-graduated ruler for the best accuracy. I used a Vernier Caliper and used the 8cm. In order to make sure the lines are parallel to the chassis, I put the Vernier Caliper in the middle of the center cap and moved the string so it sits on the 8cm mark. I had to go back and forth correcting each time to ensure I have a parallel track.

Armed with this information, you will now move the jackstands close or farther from the car to make them perfectly parallel with chassis-centerline. Since the string is thicker than the accuracy of your measurement, choose to measure visually off the inner edge of the string, and always look directly down at the string to the ruler, never at an angle.

Keep in mind that when you move the front jackstand, the distance at the back will change slightly as well, so you'll have to go back and forth between front and rear a couple times to get it perfect.

See Video below if you don't really get what I'm talking about. The video is not mines all credit goes to the YouTube account owner. It also shows how you can make sure your steer-wheel is centered.

Front Alignment check Video


If you've made it this far in this thread you must really want to learn. Good on you thumbsup.gif

Now that you have your strings tight, have a parallel chassis centerline, you are ready to make your first toe measurements. From here on, try not to bump the string or the jackstands at all! Don't open your doors or else they will snag the string and pull a jackstand out of line.

To do this, use a piece of paper and make yourself a quick little diagram like so:




Fill in each blank with the forward and rearward measurement, and take as accurate and precise measurements as you possibly can. The center blank is for the + or - toe measurement. Work systematically to prevent getting yourself confused. You will measure from the inner edge of the string directly to the lip of the wheel, first on the leading edge (towards the front of the car) and then on the trailing edge (towards the rear of the car). If anything go and watch the video ^^ again.


Write down your measurements as you go. The difference between the two measurements is the toe for that individual wheel. On the front right wheel in this example, the toe was -0.4mm. The measurement on the leading edge is 8.4cm and the Trailing edge is 8.8cm the wheel is pointing outward @ +0.4cm causing toe out. Now if the measurements were reversed 8.8cm leading and 8.4cm trailing then it would be a -0.4cm toe in.



Continue working and take measurements on all the wheels until you have completed your chart. It doesn't hurt to check that centercap-to-string measurement and make sure it is still at the "reference value". It would suck to get bad readings because the string is not exactly where you think it is every time all the time.


Again if the measurement from the leading edge of the wheel is larger than the trailing edge, that means the leading is farther from the string, closer to the middle and toe-IN. Now is a good time to go through the measurements and write IN or OUT where applicable to prevent you getting mixed up during the adjustment phase.

As you see in my measurments, I had +0.4cm toe on the front left (toe out), +0.2cm toe out on my front right, and very toe out on both rear wheels.



I won't go into a discussion here of the effects of these misalignments, but instead, we can move right on to the adjustment phase. Again you can revisit the youtube video on adjust which ever way.





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I don't normally drive fast, but when I do its on a curvy section of this island
post Aug 29, 2011 - 8:22 PM
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808celica



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Adjustment time

If you can get under your car and have access to your outer tie rod then go ahead and grab an open-end or your crescent wrench and loosen the nut locking the outer tie rod to the inner tie rod. If you're are doing the front left (LHD car side) you'll have to turn towards the rear of the car. If you're doing the LHD passenger side the you'll be turning the nut toward the front of the car.

Once the nut is loose now you can adjust. You'll either need to use a smaller open-end wrench or a small crescent wrench to turn the inner tie rod. When you tighten the inner tie rod (turning to the left if doing the LHD driver's side) you will be pulling the hub to toe OUT. Or if you loosen (turning right) the inner tie rod you will be toeing IN. Again see video ^^^, even though its an EVO the concept is the same. When there is interest in this thread I will update with picks of my car.

If you still dont get the adjusting process please post up. You'll repeat this for all 4wheels, little different on the rears but same concept

It's is NOT necessary to get this gorilla-tight, a pretty firm tug so that it won't come loose on it's own. I have NEVER had a tie-rod nut come loose on me. Plus, you might have to re-adjust it again after you check your measurements. I would suggest after you tighten the nut, turn the rod-end back a bit to make the tie rod joint roughly in the center position.

Once you get your first front wheel adjusted, move right on to the next one. You will repeat the measure/adjust/measure until everything is perfect front and rear. Again, I suggest using the ruler to measure the centercap-to-string frequently to ensure you are not drifting at all.

Once you think it's all perfect, finalize and torque everything down, roll the car back about 3 feet, then roll it forward again (steering wheel perfectly straight). Do a quick re-setting of the strings to get them nice and parallel, etc... Re-measure to ensure everything is just exactly where it should be. If it is a GO, then you can go for a test drive! First time doers will have to re-visit the adjustment process again and again to get the right toe in/out settings desired.


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I don't normally drive fast, but when I do its on a curvy section of this island
post Aug 29, 2011 - 8:25 PM
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808celica



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AND IF STILL YOU'RE NOT GETTING THIS FEEL FREE TO CONTACT ME AND WE CAN HOP IN THE CHATROOM AND DISCUSS WHAT EVER IS NEEDED.

If you already had an alignment done it is a good time to set the strings up and take measurement for reference. The measurements you get after an alignment is professionally done should keep your car in a perfect driving line.

As for me I chose to have a slight toe out (around +0.2 to +0.1 on each wheel) because of how slammed I am and my constant height changing. When I raise the car there should be a natural toe in. But all in all the measurements are relatively close from wheel to wheel.

This post has been edited by 808celica: Aug 29, 2011 - 8:26 PM


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I don't normally drive fast, but when I do its on a curvy section of this island
post Aug 30, 2011 - 9:56 AM
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KAOS



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Mahalo, Jon!

I vote ADD TO THE STICKIES!


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