Effect on Rear Axle Toe Angle from Lifting Front End of Car

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Stan Pope
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Effect on Rear Axle Toe Angle from Lifting Front End of Car

Post by Stan Pope »

I was asked about how much the rear toe angle of cambered axles would be affected by raising or lowering the front end of the car. I did some computations in these spreadsheets, but would like for someone to double check the work.

Microsoft Office Spreadsheet: http://www.stanpope.net/SharedPrivate2/ ... %20end.xls
-or-
OpenOffice Spreadsheet: http://www.stanpope.net/SharedPrivate2/ ... %20end.ods
Stan
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frontosacam311
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Re: Effect on Rear Axle Toe Angle from Lifting Front End of

Post by frontosacam311 »

I asked Stan about this but checking his work is understandably over my head. I was inquiring about how differing the cant angle on the DFW while tuning may affect rear toe.

Laying in bed last night thinking about it, it dawned on me that two birds could be taken out with one stone. I've read that when checking rear wheel alignment that both front wheels can be removed and the car can be slid on its nose while observing the rears. Always felt that the thumbtack stuck under the nose to keep the nose of the car at the final ride height seemed more logical. My gut tells me that with rears cambered, sliding the nose on the tuning board would result in rear toe in. A car with 3/8" clearance with axle hole drilled up an 1/8" would drop a 1/4" if I'm not mistaken.
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Stan Pope
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Re: Effect on Rear Axle Toe Angle from Lifting Front End of

Post by Stan Pope »

If my work is correct, raising the front axles 0,1" on a car with 3 degr camber rears would create/increase toe-out by a barely perceptible 0.06 degrees, i.e. 1/16 of a degree. I don't think that I could tweak an axle with only a 1/16 degree rotation! :)

So my prior concern for sliding on the nose vs. sliding on a thumbtack to raise the nose was probably not justified. (I am still concerned for where on the nose the car slides, though. If the contact with the slope were not in line with the CM, I think it would give misleading results.)

All moot for me, since I can have bent axles aligned true by the time the sliding test is completed! :)
Stan
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