| 35gal | -- 07-09-2011 @ 3:18 PM |
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How do you adjust the toe in on a 35/36 car.
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| supereal | -- 07-09-2011 @ 3:23 PM |
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Release the clamps on each end of the tie rod and turn it one way or the other until you get the desired toe in, then retighten the clamps. The book says 1/16 inch, but I've had better luck with zero toe in. Too much is likely to cause shimmy.
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| ford38v8 | -- 07-09-2011 @ 5:22 PM |
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I'm surprised at you, Super! The toe in is required for two reasons: one, to reduce shimmy; and two, to return the wheels to forward position after making a turn. 35gal, Support your front axle on two equal jackstands. Spin each wheel while holding a piece of blackboard chalk to the center of the tread to make a heavy line. Follow this with a black pencil to make an accurate fine line on the chalk. Measure the distance from one wheel (fine line) to the other at the front, and also at the rear. The front dimension should be 1/8" (2 x 1/16") shorter than the rear. Spin both wheels 1/4 turn and repeat the above to verify the setting. Alan
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| supereal | -- 07-09-2011 @ 6:20 PM |
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I' ve used zero toe in for years with no problems. I discovered it during my Model A days. Most old wheels have some bend in them which sets off shimmy. I have no problem in using the "right" set, of course. If you use the pencil scribe trick to find the center of the tread, and it is not true, the difference should be split.
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| ford38v8 | -- 07-09-2011 @ 10:43 PM |
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Super, it's not necessary to find the center of the tread. The pencil scribe line is only used to determine the exact plane of the wheel. Holding the scribe steady as the wheel turns, you can see how wobbly most wheels actually are, and especially how much the tire tread itself wobbles as the wheel is turned. The accurate scribe line does not wobble, and reveals the plane of the wheel. Measuring the distance between scribe lines of both wheels at the front, and subtracting that distance from the measurement taken at the rear of those same wheels gives the toe-in of the two wheels combined. On our old Fords, that measurement should be 1/8", twice the correct 1/16" of a single wheel. Alan
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| supereal | -- 07-10-2011 @ 11:04 AM |
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The reason I mention scribing a line is to establish a point of measurement so the same place can be measured as the wheels are rotated. Most who try to set toe in do so by picking a spot on the tread, and using a tape measure, usually resulting in an inaccurate result. When I was a garage mechanic, we had a device to check and set toe in. It was a telecoping bar with marks showing the amount of extension, and a pair of chains on either end. The bar was placed between the front of the tires and expanded to stay in place, with the chains just touching the floor to confirm height. Then the bar was removed and installed the same way at the rear of the tires, and extended to stay in place. Upon removal, the scale on the bar indicated the amount, or lack of, toe in. It was, as said, crude but effective, kind of like the machines that the Bear company had that allowed you to drive over them, and read the toe in. I always supected that they were designed to sell "real" alignment jobs. Front end geometry is quite complicated, affected by caster and camber, with the latter canting the top of the front wheels outward. This affects the point of toe in measurement, of course, so the points on the front and back of the wheel are critical, as camber changes toe in to toe out, depending upon the radius of the turn. This is a product of the angle of the spindle arms, so any toe in measurement must be made with the wheels pointing exactly ahead. If you have toe in set on a machine, as is the best way, the toe in is determined by the ends of the spindles. I don't believe that a 1/16" toe in can be achieved accurately in the driveway, and certainly not unless the front end, kingpins, tie rod end, and spring mounts and shackles are near perfect, and the steering gear backlash is correct. When you take the vehicle off the stands, almost certainly you will find the measurement changed by the load. I suggested that zero toe in has worked well in cases where the steering equipment was less than optimal. If your car drives well and doesn't wander, it is best left unchanged. If it does wander or shimmy, the chances are there is too much toe in, rather than not enough. The 1/16" is an overall measurement, not for each side independently, and affects straight ahead movement. As said above, toe out is produced by turns in either direction.
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| ford38v8 | -- 07-10-2011 @ 12:42 PM |
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Bob, the device you describe is still available today. Google Duby Wheel Alignment Gage. The cost is like 70-100 bucks, and what you see is what you get. I made mine from a broomstick with a pointer on one end and a yardstick on the other. This same discussion is current on the Fordbarn, and they agree with you that the wheels should be grounded. One guy suggested to put newspaper on the ground to allow the wheels to find position correctly. I did mine with wheels suspended, so I imagine my alignment could have come out more accurately, but I don't find uneven wear on my tires and my wheels center forward after a turn ok. 1/16" for both wheels combined? I always thought it was for each wheel. Now you got me thinkin'! Alan
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| supereal | -- 07-10-2011 @ 1:39 PM |
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Alan: I wasn't sure,so I looked it up. I think we are lucky that our old Fords have a solid axle so we don't have but one adjustment. The new vehicles, with front wheel drive, and those with independent rear axles are very sensitive to alignment, and require extensive adjustments to both ends. Even so, they tend to be very hard on tires. When I restored my '47, I found that someone, sometime, had apparently pulled it out of a ditch by hooking into one of the big holes in the rear of the frame. Besides tearing the frame rail, it "racked" the frame enough to pull both axles out of line, and thanks to a friend who is experienced in straightening, it was pulled back on a machine that is also used to fix unibody cars. On a convertible, any frame misalignment is evident because the fit of the doors is bad. In the process, I learned more than I wanted to know about front ends. The car now drives and handles very well, even at highway speeds.
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| Stroker | -- 07-10-2011 @ 4:32 PM |
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There is no "ideal purpose" to toe-in. Toe-in is an adjustment we make to offset the natural toe-out that occurs due to the slack tolerances that stack-up due to the fact that king pins, tierod ends, wheel bearing running clearances, axle flex, tire distortion etc. combine to cause the wheels to naturally tend to toe-out. So what we do by cranking-in toe-in is to neutralize these combined effects by adjusting the linkage to compensate. Some suspension systems are more prone to this combined distortion than others. Modern rubber/polyurethane bushed systems have more movement than a good old Ford I-beam/tube front axle and metal-to-metal tie rod system has. Having said that; the amount of measured toe-in you need to crank into your old Ford is a function of the condition of all those tolerances listed above. If you have worn king pins, loose tie rod ends, and sloppy front wheel bearings, then you need to compensate by adding more toe in so that when the "rubber meets the road", your front wheels are going in roughly the same direction. A good indication that you do not have enough toe in is a propensity for the car to "wander". Some decades ago, I was a successful Bonneville competitor. I ran 1/32" total toe in on my little racer, as it had a 1/4" wall chrome moly tube axle and aviation-grade Heim ends in lieu of tie rod ends, that was about as rigid as one could make. My brother was running a car that had a thinner wall-section axle, and he asked me to set his toe in. I'm glad I didn't kill him, as I set it up like mine, and it was "all over" the course. Difference?..axle flex.
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