Alignment Setting Toe

Discussion in '80-Series Tech' started by Tools R Us, Dec 5, 2010.

  1. Tools R Us

    Tools R Us

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    On the ’80, toe is the only thing easily adjustable. It can be knocked out from wheeling, impact, so should be occasionally checked.

    For something that looks deceptively simple, vehicle handling is a complicated subject, there are great books on the subject, this will be the simple version: Toe-in enhances high speed straight-line stability. If set at zero the tires are free to move, play in the system isn’t taken up, steering feels light, prone to darting. With some toe-in, the tires are loaded slightly at odds with each other; this reduces the effect of play in the system, makes the steering feel more solid and reduces the darting effect of bumps. Overall, makes the rig more comfortable to drive. The stock spec is 0-.160”, I find that lifted, big tire rigs like a little more, at the top of spec. If the rig has been modified, it is often best to experiment with settings to find what works best. Like most other alignment settings, a lifted, big tire rig is likely to want different settings than a stock rig for best handling.
    toe_spec.jpg
    Last edited: Oct 1, 2014
  2. Tools R Us

    Tools R Us

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    The “best/easiest” way to set toe is by angle/degrees, if you have the equipment. With some care, setting it with measuring tape can be done just as accurately, as long as changes, like tire size, etc are taken into account.

    There is a ton of ways to do it and most are very successful, this is the one that I prefer. The stock spec is for stock tires, so ~30” OD, measured half way up the tire, so about 15” from the hub. There are a couple of problems with this: First, my tires are 37”, so would have to do the math to come up with the correct number. Second, there is often “stuff” (arms, etc) in the way, making measuring at tire centerline difficult. I use two, 30”+ long, straight, pieces of scrap material, in this case angle iron, but anything similar will work. Mark the center, the ~15” on each side of center, the same on both pieces.

    Put the rig on stands, remove the front tires and clamp the bars to the rotors, with the center marks under/centered with the hub. Confirm that the steering is centered; I sight down the length of the bars and look for them to lineup at the same spot on each rear tire. Adjust so they are somewhat level and even with each other. Measure the distance between the bars at the front marks (front side of the axle), repeat at the rear marks (behind the axle). The difference between the measurements is your toe; we are looking for toe-in so the front measurement should be shorter by the amount of toe desired.

    If it needs adjustment, loosen the clamps on the tie rod and turn it until the measurement is where you want it. If you have a rust bucket, this may involve lube, heat, hammering, swearing, etc.:hillbilly:
    toe_1.jpg toe_2.jpg
    Last edited: Dec 5, 2010
    gdctaco likes this.
  3. Tools R Us

    Tools R Us

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    The next step is to set the knuckle stops. Anytime the tie rod has been adjusted, it is very important to confirm that they are correctly adjusted. Their job is to stop the turning of the knuckle, at the knuckle, when the tie rod is adjusted, one side will hit the stop before the other. If the side that isn’t hitting is jammed (like against a rock) the force will be transferred to the other side, through the tie rod, a leading cause of tie rod, steering damage. The goal is to have the stops contact on both sides at the same time. Check/adjust with the steering turned in both directions. Alignment shops often overlook this step.

    The last adjustment is centering the steering wheel. I prefer to do it by driving, so assemble, torque everything and put the rig back on the ground. Loosen the clamps on the drag link; get it loosened up, so it turns easily. Drive on a relatively straight, level road, if the wheel is off center; turn the drag link to center it.

    Once done a couple of times, this is a simple, quick job. One of those things that almost takes longer to talk about than do.
    toe_stops.jpg
  4. krzyabncanuck

    krzyabncanuck GOLD Star

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    That is the way we did this in country on our GMV's / HMMVW's ( Stan and or Iraq ). After i rebuild a truck i do this to get it to the alignment shop also. Unless it is mine and then i just do this to it and call it a day.

    Very good posting.
  5. landtank

    landtank SILVER Star

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    how are you confirming that the turning angle is within 32-35 degrees after adjusting the stops?
  6. Tools R Us

    Tools R Us

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    In my experience, that is about the middle of the stop adjustment, like it is stock. You can measure, set rig center line, use a protractor to confirm turn angle from center line. I just adjust the stops to keep them close to the middle of the range, adjust one in a tad, the other out a bit. The important part is; the stops need to hit on both sides at the same time, so the full lock force is carried by the stops on the knuckle, not the steering parts.
  7. Turtle Master

    Turtle Master

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    Good info.
    Last edited: Dec 5, 2010
  8. 80t0ylc

    80t0ylc Hill & Gully Rider SILVER Star

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    Wow! Good job & easy to understand. Definitely FAQ material. Thanks for posting!
  9. 94SRUNNER

    94SRUNNER GOLD Star

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    Great step-by-step Kevin! Thanks for taking the time to put this together.
  10. Turtle Master

    Turtle Master

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    Charleston WV
    I liked your fan clutch info. Kevin. Thanks.
    Last edited: Dec 5, 2010
  11. SUMMIT CRUISERS

    SUMMIT CRUISERS SILVER Star

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    Kevin, Thanks for the tip on the knuckle stops. I never have checked them, but I did adjust my toe-in and drag-link this morning. I use a piece of 4' long x 3/8" round bar stock with one end ground to a point. I position the point on a symetrical spot/line/tread mark on the inside of the tire (rear and front) and then use the flat end with a metric metal ruler to get my readings for the open space. Works very well.
    Thanks again for your helpful tips.

    Steve

  12. landtank

    landtank SILVER Star

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    one thing to consider about the stops, they will influence the caster sweep readings. Not that it will actually influence the caster itself, just the reading.

    I would recommend only adjusting the rear stops and leaving the front ones at the factory setting. This way you're not influencing the turning angle just compensating for the amount of toe you introduce.
  13. Tools R Us

    Tools R Us

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    One more detail. When re-tightening the tie rod clamps, the FSM recommends positioning them as pictured. For most setups it works, the point is to position them so they don't interfere, hit anything.
    toe_clamps.jpg
  14. Romer

    Romer fatherofdaughterofromer Moderator

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    Nice job Kevin! Thanks for putting it together
  15. landtank

    landtank SILVER Star

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    Like the control arms when you have plates installed.
  16. Tools R Us

    Tools R Us

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    18,224
    Location:
    Chandler, AZ
    I would think, if one had access to an alignment rack, they would not be setting toe with a tape? If they did have access, they would set the stops using the turn angle gauge on the rack? Unfortunately most alignment techs have the goals of; making the rig drive acceptably, making an explainable printout and doing it in the shortest time possible. So things like turn stops are "overlooked".:eek: Most have no concept/knowledge of how to setup a rig for off road strength and don't care.

    The caster number is nice trivia, but isn't adjustable. I have never seen a published caster number for my rig, so don't see the point of putting it on a rack and checking it. This was written for the user who understands that the only routine maintenance alignment adjustment on an '80 is toe and wants to be able to check/adjust/properly set it up himself.

    Do it however you like, but I disagree. If the stops are adjusted correctly, very few that I have seen are, and you dial toe-in, the front stops on each side will hit first. By adjusting only the rears, turn angle will be reduced. Toe-out will be the opposite. This is why I split the difference, adjust the front and rear stops about the same amount.
  17. sunrk

    sunrk

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    Caster is adjustable by using bushes, plates, radius arm drop-boxes, or aftermarket radius arms. All of these products re-adjust the rotation of the front axle housing to compensate when an 80 is lifted. The factory spec for caster is + 3 degrees, and the castor angle without any correction reduces by about 1.75 degrees for each inch (25 mm) of lift.

    Camber is also adjustable - but it requires fitting special top kinpin bearing caps that alter the position of the swivel housing (and therefore the wheel hub and spindle) relative to the position of the top kingpin bearings, which modifies the camber angle. I don't know how much adjustment is possible because the bottom kingpin bearing position doesnt get changed.

    There is a truck/4wd wheel alignment place here in Australia called Pro-Axle that makes camber-correcting top kingpin bearing caps. Not very common, but heavy-duty driving of a 4wd can cause the front axle housings to become bent and the swivel balls to no longer be in ex-factory vertical alignment.

    Craig.
  18. 86tuning

    86tuning

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    Good tech. Thanks
  19. bmac1996acc

    bmac1996acc SILVER Star

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    Slee has camber bearings too
  20. blkprj80

    blkprj80 SILVER Star

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    Thanks Tools R Us for the excellent post and inspiration.
    I am adjusting mine after doing a full front end service including tie rod ends.
    It was much easier to remove the tie rod and work it over in the vise with a pipe wrench. Man a couple were killer frozen!

    Anyhow, for alignment, I used your idea, but I used some aluminum straightedges and some spring clamps to hold them to the rotor. That rotor better be straight and flat or I'm SOL on other fronts! I used a couple pieces of good ol' balin' wire to support my straightedges. In the picture, the ends are floating and the pipe is for support only when setting it up.

    I made sure both sides were in very close the same place (front to back). I then marked a tick right at 36" from the front end.

    I measure the distance at the tip and then at the 36" mark. Inside rails, outside or whatever, it doesn't matter. All you are interested in is the difference.

    If my math is correct, at 36" apart, the following is true:

    0.2 deg toe is 0.126" or 1/8"
    0.4 deg toe is 0.251" or 1/4"

    So there you go - if you are shooting for "spec" of 0.2 +/- 0.2, you go for 1/8" difference.

    It doesn't matter if your marks are ahead and behind the tire, so long as the sides are even. And if your marks are 36" apart, you can use the math above.

    So now the question: What is everyone's favorite toe number? I don't know for sure, but I think mine may have been very close to 0.0 before. I thought I had read somewhere that 0.0 was preferred by many.

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