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Precise Alignment with a Digital Level

Discussion in 'The Hokey Ass Message Board' started by scottybaccus, Nov 1, 2009.

  1. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    You're on the right track. Toe IN is most used on street cars and drag cars to keep the steering links in compression to avoid the shopping cart boogie and wandering. This is the prefered state because any bump on one side of the car will tend to add to this compression, minmizing any influence over the steering.
    A lot of circle track and tight road course tuners prefer toe OUT instead to keep all the steering links in tension. When you have toe IN, you will achieve this state in a corner as the ackerman pulls the inboard wheel tighter into the turn than the outside wheel. When you straighten up, it returns to a compression state. The switch between compression and tension, and back, can sometimes introduce a bobble in the steering at less than opportune times. Setting the toe OUT keeps the parts in tension all the time and eliminates any chance of this issue in the transition. Too much toe-out, combined with a bump, can lead to unexpected lane changes and swapping of ends. Use with care.

    True. If you have curvy rockers or a tapered frame, just drop a plumb bob on the centerline of the car and measure from there to set up the strings.
  2. Don's 55
    Joined: Apr 17, 2009
    Posts: 92

    Don's 55

    I did something similar with my Camaro when I was ready to get it back on the road.
    The car went through a complete restoration.
    I bought a digital 6" level from Sears, about 30 bucks?
    My plan was to get it close and take it to my nephews to be aligned.
    When he put it on the rack it was spot on. We just tweaked it to get it a little tighter.
    I was able to watch him do it and gave him some specs that are a little different from the factory (Pozzi Racing). Most shops won't vary from the factory specs, so doin it with a level can be useful.
  3. oldsman32
    Joined: May 2, 2006
    Posts: 17


    Hi guys,

    As a dyed in the wool hotrodder in the alignment business, I figured I'll throw this out there cause I feel your frustration. I've speciallized in performing wheel alignments for over 35 years now and have earned the respect of local car guys who have run into the same crap you've talked about out there. You've heard it all. Can't be with the car at the shop cause of insurance reasons, don't have the specs or know how to set up a 40+ year old car, ect. I ran a wheel alignment shop for 15 years, but had to shut it down due to the corporate mentality that showed up when the guy who owned the shop sold it to some big wigs. While there, I enjoyed working with the car owners to solve their handling problems. That was 8 years ago and now I work in a shop that has all those crappy rules, plus they don't want me to even consult with the car owner, which takes all the fun out of working on rods and specialty cars. So what's a true hotrodder to do? Set up his own alignment system in his shop at home so he can offer wheel alignment service to the local hotrodder who wants that one on one service that he feels he should have. So here's the deal. If you live in or near southeastern Pa., contact me if you need your rod set up without having to put up with all the nonsense that's out there.
    pat59 likes this.
  4. budrow
    Joined: Jun 25, 2009
    Posts: 115


    Hope it ain't too late to thank you for this post. That $60 dollars for a linejob is being spent on a digital level and I'll line it my ownself. Thanks agen for the the great post. budrow out.
  5. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    Never too late! Glad you got to it.
  6. thequietwon
    Joined: Mar 21, 2006
    Posts: 600


    As someone who services the alignment equipment itself, the problem with most systems is that they have to have sensors or targets hung on the rear wheels. On a car as low as my '55 or '57, combined with the way the quarters are made, this is next to impossible to do. When necessary, I align my cars as detailed above, but I bought an inexpensive camber/caster gauge (less that $70) and use a set of old turnplates with the steering angle gauges still attached. Turn to the 20 degree mark in each direction, and take caster measurements...makes it alot easier. By the way, a recently updated Hunter aligner should have most vehicles back to the 50's...and manually inputting older specs is extremely simple!!!
  7. Johnny1290
    Joined: Apr 20, 2006
    Posts: 2,834


    I hate alignment shops, only had bad experiences.

    I rebuilt the front end and set the toe in with a broomstick and a piece of chalk. Worked fine, but I think I just got lucky since I didn't check camber or caster, plus I never drive over 35 or 40.

    I just installed a new tierod setup, this time I have a toein gauge from longacre racing(awesome!), and I got a magnetic hub mounted bubble gauge I paid around $50 for, and I'm going to set it up right.

    I'd love to have turning plates, but they're $$$ unless you get lucky at a swapmeet, so I'm going to use some masonite squares with some chassis grease between them, instant plates. I heard newspaper and lube works as well.

    Anyway, if a laser alignment on a rack is so great, why do indy cars string them instead? I've seen them do it, seems to work alright for them.

    Thanks for shining a light on this black art, Scotty!
  8. HemiRambler
    Joined: Aug 26, 2005
    Posts: 4,208


    The string doesn't lie, but a laser CAN get bumped and screwed up and you not know it.

  9. Yo Baby
    Joined: Jul 11, 2004
    Posts: 2,812

    Yo Baby

  10. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    That's exactly the reason I posted this procedure. I already had the digital level and it really pained me to pay another $100+ for one of these. Now you have a choice, buy one of these, or go get a digital level that may serve you much more often in many more ways.
  11. Mr48chev
    Joined: Dec 28, 2007
    Posts: 29,584


    I'm probably one of those "old timers" who told him that and he is correct in that you always want to set the toe in last.

    Depending on the car you set the camber or caster first or work at it to get both but it isn't quite as simple as you make it out on a lot of cars as resetting one will most often change the other.

    That style of front end is a little easier to do the camber then caster on though.

    You are doing way too much unnecessary work setting the toe in. Fancy but not necessary and possibly not too accurate.

    I've set toe in on hundreds of cars by jacking up each wheel and scribing a line on the center of the tread as you spin the tire slowly you have to have something to hold your hand solid and I usually used a pencil to make the mark. Do both tires and measure line to line at the front of the tires and line to line at the back of the tires. the difference is toe in or toe out.
    That compensates for any and all wheel and tire runout that you might have.

    To center the wheel I usually centered the wheel before I adjusted the toe in and then sighted down both tires to the rear tires and made my adjustment on the side that was off and went from there. That's with an independent, it won't work with a solid axle.

    I'm not saying you are wrong to do the string thing but you are making it a lot more work than it needs to be.

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  12. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    You are absolutely correct! The string is for checking rear axle position, front wheel relationship to center of the car, setting the K on the floor, etc. If we only need to set toe, I could make it really easy. You don't even need a chalk mark on the tire. Just hook your tape on a tread block and measure to the same tread block on the other side.

    This is how anyone can do a FULL front-end alignment at home. Squaring the rear axle and thrust angle will be another article.

    Glad you liked it!
  13. Are there any "secrets" you guys mind sharing?

    My wife was hit in the rt front tire on her 93 s-15 Jimmy
    Bent the upper a arm, ball joint Ect
    Easy enough to find parts for so I rebuilt that side
    I used the string method, I measured the drivers side caster at 3.4 and matched that on the pass side

    Only complaint is it has more of a tendency to fade to the right, falling down the crown of the road more than it use to.

    Anything I should try differently?
    David Gersic likes this.
  14. langy
    Joined: Apr 27, 2006
    Posts: 5,735

    Member Emeritus

    Not sure if you have these in the U.S but i use Dunlop tracking gauges, you can pick them up pretty cheap these days.

  15. To much fancy stuff :D. I use only a plum bob. Camber off the side of the rim, Caster with a mini bob between balljoints, Toe of the center line of front and back of tire to mark the floor.

  16. These were a factory tool for aligning BMW's back in the day. They were purged from the factory tool list 10-15 years ago, I know quite a few BMW tech's who "borrowed" them from the trash bin.

    When I did alignments, we loaded the car by putting sandbags in the seat to simulate a driver and passenger. I don't know how much it affects the final alignment, but worth thinking about.

    When I set the toe on a car I always sight from front tire to rear tire on each side to see where the front is in relation to the rear, this way you can make sure each side is the same, and your alignment is centered. I got to where I could eyeball the toe pretty close. Modern 4 wheel alignment systems do this electronically, all of the frontend settings are based off of where the rearend is.

    Excellent tech, especially the caster measurement part.
  17. Cshabang
    Joined: Mar 30, 2004
    Posts: 2,458


    First, there is an order in which you should perform an alignment, assuming everything is close enough to be fairly road worthy to start with. If you just assembled the thing, get it all close before you get detailed. First, set the Toe (in, or out as you wish), then set the Camber, finally the Caster. Recheck everything. Adjusting Caster or camber affects Toe, adjusting Toe messes with the caster measurements, etc.

    Im sure its been posted by now, but You usually start with Camber, then Caster, and finally least thats how I was taught (when i was training in the Ford ASSET program)...and reason you say start with toe? esp since adjusting the others will effect it?
  18. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    The devil is in the details, right?

    Yes, there is a reason to start with toe. Most of my work is on new assembly or major overhaul, so it is necessary to get everything close first, but toe can affect the range of the turn to each side, particularly if it is off too far. Set it first and you will be able to start with the correct range of turning on the caster measurement with little affect on toe later, presuming you were close. All bets are off if you miss by much in round one. In a nut shell, plan on running the full circuit two or three times. By the time you're done, it's the chicken or the egg situation.
  19. May I question one statement? I work at a shop that does old fashion alignments and we use a scribed paint stripe to be used to measure toe set.
    The statement based on measuring from like tread blocks on a tire can and will bring problems. I'm saying this because internal tire separation can occur with not enouugh visible tread shift to be seen. This can even be with defective brand new tires.
    Aside from that one detail, this is good scientific info for a good alignment. The late model electronic guys had better know how to calibrate their equipment quickly and accurately because after the first whatever that causes miscalibration happens, every job afterwards will be misadjusted the same or worse from there on.
    It doesn't matter if it's a hot rod, Honda car, or Kenworth. Good science.
  20. Cshabang
    Joined: Mar 30, 2004
    Posts: 2,458


    Makes perfect sense...thanks for the explanation...never thought of it that way.
  21. Oh yea, I went through the whole thing several times, getting closer and closer each time

    One thing pops to mind that may have thrown me off
    Does this method account for the slight angle in my garage floor?

    It tracks nicely most of the time, just fades a bit more to the right on some spots where the road is really crowned.
    I was curious if there was a slight adjustment I could make to help that.
  22. I always take chaulk and mark the floor where tires are then roll car back and check the floor at the 4 corners. Just use 1/8 ply and sheet metal to make all 4 corners level.
  23. big creep
    Joined: Feb 5, 2008
    Posts: 2,945

    big creep

    cool tech, but i just take it to my buddy troy at B&I frame in b,urbank, they dont act like dicks! and they know how to work on a hot rod, and a custom and even new off topic stuf. i would do it, but i know i would screw it up somewhere?
  24. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109


    You will need to compensate for the angles in your garage floor. With regard to camber, measure which way the floor leans and add or subtract in the right direction.
    Caster is a little easier to understand. Say you are parked with the nose uphill, measure caster and add the degree of the slope, facing downhill, subtract it.

    You can compensate for crown in the road with IFS (solid axle is just very difficult for little value. By adjusting camber to match more closely the crown in the road, you diminish the tendency to pull BUT, the crown will have different angles in each wheel track, so the adjustment differs left to right.
    The downside of doing this is that you now have a car that will pull the other way on a level surface and likely accelerate wear.

    The number one thing to remember about alignments is... (ready?, this is where the arguments start)...

    Close is good enough. Why? Unless you have a specif track and the car is dedicated to it, your road surface is always changing. The variations in the road, plus the variations in your rubber, plus wind, plus weight change, all means your alignment settings are not terribly constant. You need settings that are a good working average for your typical enviroment and habits. Drive a lot of hiway miles? Go big on caster to lessen fatigue. Do a lot of low speed corner work, go small on caster to corner easier. Have a couple of homies with above average beer belly type profiles? Set your caster low for the corners, then throw these guys in the back seat to add caster for the hiway trip. Use your car on lots of freeways? Set both sides the same. Dream of a career in NASCAR, learn about stagger. There just is not one right answer. The factory specs try to put you in the middle of the "normal" range for the vehicle usage. I like 5-8 degrees of caster to keep things calm on the freeway, but the wife's '62 Falcon calls for about 2 degrees. Go figure!
  25. luckyuhaul
    Joined: Jul 11, 2005
    Posts: 182


    Good thread!

    How does "ride height" figure into alignment?
    If you have a vehicle with other than stock height , how do you compensate for this change?
    Trial and error or is there a way to factor this in to stock settings?
  26. sdluck
    Joined: Sep 19, 2006
    Posts: 2,750


    Some cars, ifs, we used to add .5 caster to rt sides for road crown. Weight will effect readings on ifs cars. Specs are usually for 1 driver at 180 pounds
  27. It changes caster. Think of the forks on a bicycle looking from the side. The forks have an angle to them, thats caster. Now if you raise or lower either end of the bike the angle of the fork changes. This same thing happens to the spindles on a car. Spindles to a car is like forks to a bike. I hope this helps.
    Joined: Mar 12, 2006
    Posts: 263


    Great thread. The digital levels are fantastic for home alignments, no need to buy an expensive "race" gauge. Twenty five dollars at Sears. My slip plates are 1 foot squares of flooring, placed shiny side together with a little grease. I made a toe gauge from conduit with sliding pointers. I learned aligments over 30 years ago in a shop I worked at as a kid, when the machine didn't think for you, and you can duplicate when the new machines can do with just the items listed in this thread.
  29. I always used a plumb bob )aka a piece of string with a heavy washer hanging down. from the fender for camber and from the upper ball joint bolt over the lower ball joint for caster. The K is a neat trick . Thanks. I also hate $100,000 algnment machines with green or red when it is good or bad. I got tired of explaining the specs i needed so I always do my own in house. I also use the jack stand string deal.
  30. MrBullet
    Joined: Mar 20, 2011
    Posts: 17


    I have been in the auto repair business for over 30 years and I am still amazed at the shops that try to make front end alignment sound like rocket science. I use a Howe magnetic caster camber gauge with 3 bubble levels in it that I have had for years. Never had a problem. Dont be afraid to do it yourself, if you buy a gauge and use it one time, its paid for itself and you dont have to hear all that bull shit from the idiot at the alignment shop

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