Front End Alignment Changes -- Toe-In

[H. L. Chauvin]

FWIW:

Maybe something to consider as to why Model A's may wander "occasionally" when driving on different or the same highways:

1. According to the Model A Ford Service Bulletins Book, & current recommendations, it is advisable today to follow Ford's revised toe-in measurements from that of the earlier 3/16" to 1/4", to the later prescribed toe-in of 1/16", + 1/32"; & naturally, remembering that this 1/32" is only about a very tiny dimension of 0.031".

2. Next, many agree that Model A wheels are quite serviceable if they only "wobble-in" or "wobble-out" approximately 1/8" from the center of rotation, or something close to this recommendation. (Some may wobble more, some may wobble less, some may wobble as much "in" as "out" of the axle's center. LOL).

3. Then upon providing just one (1) single very accurate alignment, while setting toe-in at exactly 1/16" toe-in while using Ford's toe-in tool, curtain rods, wood jigs, etc., with measured & tested "acceptable" wobbling tires/wheels, one may expect to experience:

A. A "toe-in" of approximately 5/16" if both front tires are in a "wobble-in" position of 1/8" from axle center, i.e., (-1/8") + (-1/8") +(-1/16") = (-5/16"); &,

B. A "toe-out" of approximately 5/16" if both front tires are in a "wobble-out" position of 1/8" from axle center; i.e., 1/8" + 1/8" +1/16" = 5/16"; &,

C. Then after driving around curves & corners, with one front wheel rotating faster than the other, one could theoretically experience different dimensions of maybe approximately 5/8" measured between the fronts of the two (2) front tires. Interesting?

D. If one subsequently verifies one's Model A toe-in, several times, each time a few days later, after driving around several miles, one may think his tie rod may be turning slightly & or his toe-in moved & needs to be re-adjusted.

E. May be a good idea to carefully look more closely at one's adjusting of one's front end alignment to decide which dimensions works best for which of his 80+ year old "wobbling" tires/wheels.

[Russell in Tulsa]

Food for thought eh?

[Marco Tahtaras]

I'm not sure it that is "over thinking" or the opposite. When the original Duby gauge is used (properly), wheel wobble is completely removed from the equation. That makes all other premises irrelevant.

[d.j. moordigian]

"
C. Then after driving around curves & corners, with one front wheel rotating faster than the other, one could theoretically experience different dimensions of maybe approximately 5/8" measured between the fronts of the two (2) front tires. Interesting?
"

So, are you saying "wobble" or "Ackerman", or both? It depends on the radius,
I would think. Ford also changed the ackerman in the front end in late 28 or 29.

[BILL WILLIAMSON]

Originally Posted by Russell in Tulsa

Food for thought eh?

WAAAAY too much "food"
Just run straight wheels, set the toe in properly & forget about the Ackerman Angle!
ALL cars wander, just observe the small corrections your hands make when you drive, to keep you in your lane. Also, consider the 4 small tire footprints that keep you "stuck" to the pavement---NOW, THAT'S SCARY!!!!
Bill W.

[Patrick L.]

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Spin the tires to check the 'wobble', then set the wheels in a position to split the difference.
Set the toe and go.

Most wheels on most vehicles are 'warped' and this should be taken into account when doing an alignment.

Once you look at the front end parts you'll notice that the wheels are not pointed in the same direction during a turn, supposed to be like that. This is an over simplistic answer, but....

[H. L. Chauvin]

Comments above are correct.

No doubt straight wheels can contribute to better overall steering where the distance between the "front" of both front tires remain constant.

However, the main problem with Model A "wobbling" wheels appears to be that in theory, all vehicle front wheels want to go where they are pointed; hence, with one or two "wobbling" Model A front wheels, & each or both wheels maybe pointed in different directions, they are sort of like (2) "wobbling" drunks walking down a sidewalk unsynchronized ..... & definitely not pointed in the exact same direction.

Bill, I just know you can explain this Model A front wheel intoxication better than I can.

[Marco Tahtaras]

Originally Posted by H. L. Chauvin

Comments above are correct.

No doubt straight wheels can contribute to better overall steering where the distance between the "front" of both front tires remain constant.

However, the main problem with Model A "wobbling" wheels appears to be that in theory, all vehicle front wheels want to go where they are pointed; hence, with one or two "wobbling" Model A front wheels, & each or both wheels maybe pointed in different directions, they are sort of like (2) "wobbling" drunks walking down a sidewalk unsynchronized ..... & definitely not pointed in the exact same direction.

Bill, I just know you can explain this Model A front wheel intoxication better than I can.

Ok, I get where you are going. However the wobble in the wheels can impact balance but that's about it unless the wobble is huge such in inches. Otherwise the wobble does not impact direction. Direction is determined by the axis. The axis will remain true unless the wheel bearings are loose!

As an example, Jack up one wheel slightly and spin the wheel and draw a chalk line as close to the center of the tire tread as possible. If the chalk is held in a fixed position as the wheel is spun then any wobble would show as slightly more tire tread on one side of the line at one point and more on the other side of the line at a different point. The line however is where the wheel will 'aim' or track, not the edges of the tread.

[H. L. Chauvin]

If one or both front wheels are bent inward at one spot, & bent outwards at another 180 degree opposite spot, one could park the vehicle where at one time the front wheels could be slightly pointing inward & the next time the front wheels could be slightly point outwards ....... or both pointing either left or right.

The axis will remain true, but these wheels would appear to act like they have loose wheel bearings ....... just like the shopping cart always parked by the front door at a Wal-Mart.

[mshmodela]

Originally Posted by BILL WILLIAMSON

WAAAAY too much "food"
Just run straight wheels, set the toe in properly & forget about the Ackerman Angle!
ALL cars wander, just observe the small corrections your hands make when you drive, to keep you in your lane. Also, consider the 4 small tire footprints that keep you "stuck" to the pavement---NOW, THAT'S SCARY!!!!
Bill W.

yes my size 13 boots are widered than my A's tire s

[glenn in camino]

I once prepared 15 wheels for repainting. I checked each one for wobble by spinning it with a block against it. The best one, no cracks ,no pits, perfect finish, and round, had a 1/8" wobble.

[H. L. Chauvin]

What Marco describes is correct in that front end alignment is really adjusting the two front spindles such that the front wheel nuts move very slightly forward to provide toe-in.

Then for said spindle adjustment, toe-in settings for the front spindles are measured on the tires at the same points after moving & rolling tires approximately 36" forward.

If one has perfect or near perfect wheels/tires, one can rotate or change out perfect or near perfect wheels/tires every month & almost never have to readjust front end alignment of the spindles.

From an experiment this past weekend, I had near perfect tires out front with close to 1/32" toe-in.

Then I rotated tires with non-perfect tires & immediately noticed perceptive wandering ..... plus each time I rode out & returned, I noticed the front tires pointing in different direction, similar to that in reply no. 9.

I re-adjusted toe-in from 1/32" & increased it to 3/16" & the wandering stopped on the wobbling tires.

Then I removed the wobbling tires & substituted the front tires with the almost perfect ones & re-set alignment back to 1/32" & had no problem.

I guess the bottom line is:

If one only has "wobbling" Model A tires, & one gets discourage because one's Model A wandering when driving, changing the toe-in slightly can make a big difference.

That is what I was trying to point out in post no. 1, in the last paragraph E.

Have to go back to work.

Just hope it can help someone some day.

[Marco Tahtaras]

Originally Posted by H. L. Chauvin

What Marco describes is correct in that front end alignment is really adjusting the two front spindles such that the front wheel nuts move very slightly forward to provide toe-in.

Then for said spindle adjustment, toe-in settings for the front spindles are measured on the tires at the same points after moving & rolling tires approximately 36" forward.

If one has perfect or near perfect wheels/tires, one can rotate or change out perfect or near perfect wheels/tires every month & almost never have to readjust front end alignment of the spindles.

From an experiment this past weekend, I had near perfect tires out front with close to 1/32" toe-in.

Then I rotated tires with non-perfect tires & immediately noticed perceptive wandering ..... plus each time I rode out & returned, I noticed the front tires pointing in different direction, similar to that in reply no. 9.

I re-adjusted toe-in from 1/32" & increased it to 3/16" & the wandering stopped on the wobbling tires.

Then I removed the wobbling tires & substituted the front tires with the almost perfect ones & re-set alignment back to 1/32" & had no problem.

I guess the bottom line is:

If one only has "wobbling" Model A tires, & one gets discourage because one's Model A wandering when driving, changing the toe-in slightly can make a big difference.

That is what I was trying to point out in post no. 1, in the last paragraph E.

Have to go back to work.

Just hope it can help someone some day.

Get the proper tool and that will not occur. They still make them.

[Marco Tahtaras]

Ok, It's clear that folks don't understand how the proper tool works. When used properly it fully compensates for bent/wobbly wheels. That means it always sets the spindles to the proper relative angles. You can set your toe in with one (any) pair of wheels and then change the wheels and check it again. You will receive the same reading with no adjustment necessary.

By contrast, if you use ANYTHING that requires removing from one location on the tires and measure another location, I'd guess the odds of accuracy is something above 10,000:1

Check my link: http://abarnyard.com/workshop/align.htm

[KR500]

Marco has it right. The Model A Ford king pin inclination creates the need for toe in. The tire assembly creates a cone of the tire and wheel and when rolling a cone on the ground the cone wants to toe out, hence the need to toe in the wheels. The Ackerman principle is to get the left tire assembly to toe out more because it will roll on a smaller radius than the right tire/wheel on a left turn.The right or outside tire on a left turn will need to roll on a larger radius. If rear axle is in proper position (not shifted or bent) its center line is the radius established for the center turning radius of the car. King pin inclination is what gets the king pins centerline to intersect the road at the center of the tire/wheel assembly. This then allows all the steering effort to be exerted on the bearing around the king pin. Tire scuffing is caused when toe in is incorrect. The toe in requirement (measurement) is actually established by camber and king pin inclination. When these measurements change the cone size and shape change requiring a different toe in requirement. Make some different paper shaped cones with two different angles and roll them on a table, turn the cones to the point where you can roll them in a straight line and you will notice you have to turn one cone more than the other.

[H. L. Chauvin]

"When these measurements change ... the cone size and shape change ..... requiring a different toe in requirement."

This is what I was often told by vintage professional mechanics, especially when working on vintage vehicles like Model A's in the 1930's & 1940's.

Many Model A's had bent axles either caused by crossing high railroad tracks, curbs, countless pot holes, or having the front axles improperly jerked by someone pulling someone out of a mud hole with a chain.

Many small shops had no axle bending ability; hence, alignment toe-in dimensions were sometimes tried, varied slightly, & were set by trial & error as opposed to strict manufacturer's recommended measurements.

When I bought my 1930 Town Sedan, it was odd to find the front wheels set at 1-5/8" toed out ..... the former 20 year owner said he bought it like that & never checked it or tried to adjust it.

[colin1928]

Originally Posted by BILL WILLIAMSON

WAAAAY too much "food"
Just run straight wheels, set the toe in properly & forget about the Ackerman Angle!
ALL cars wander, just observe the small corrections your hands make when you drive, to keep you in your lane. Also, consider the 4 small tire footprints that keep you "stuck" to the pavement---NOW, THAT'S SCARY!!!!
Bill W.

Not SCARY
all things being equal our small footprint give as much or more grip,
to grip the road you need
1 hard V soft
2 texture
3 contact area
4 pressure lbs per square inch
doubling the contact area halves the lbs per inch

[CT AV8]

I believe the best and most accurate way to set toe is with "toe plates" bolted to the spindle. The plates can be as simple as a length of steel bar matching the tire diameter with a center hole or can get more complex with pointers and indicators. Very easy to fabricate and use. Anyone who's done circle track racing will be very familiar with this approach.

[H. L. Chauvin]

Seems always a good idea to begin with a properly adjusted axle.

No doubt Ford's original axles met Ford engineer specifications for which they recommended a specific toe-in for their design.

It would appear interesting to hear from gentlemen who have actually straightened a few used Model A front axles ..... and to report how many were found to meet Ford's original specifications ..... and how much & where did most dimensions differ.

Every axle I ever saw was bent forward from the center & appeared to be bent from towing or pulling out of mud holes with chains.

[Kurt in NJ]

To further confuse----in 1936 Ford came up with a newalignment machine for dealers to buy, it worked in degrees, and toe was to be set at 1/10 of the total camber---the example given--if camber is 1 degree total toe would be1/10 of 2 degrees, or 12 minutes ---and it goes on saying for cars with less than 2-1/2 degrees caster a slightly higher toe is required
there is a chart that includes A, and shows toe as 3/32"*, with * refering to the 10-1 ratio

[H. L. Chauvin]

Not too confusing.

Sounds like what I thought I had heard, i.e., a front end alignment math equation for mechanics dealing with non-aligned kingpins associated with many slightly bent front axles; hence, setting a subsequent toe in dimension or degrees changed from what was originally recommended by the manufacturer for perfectly straight axles.

Thanks.

[MrBruce]

I agree, I bought what I think is a neat tool for Model A's. It looks just like the pictures for aligning the front ends. It's called "Wheel Alignment Gauge" and is sold or made by S&G Tool Aid Corp, Newark, NJ. It has the gauge readout and the chains. You put it in the front with chains touching the ground, move the car forward until the chains touch in back of the tire then read the tow-in. I haven't used it yet (hopefully this weekend) and will let you know how it works. Even the brand new Model A wheels that Snyder and Bratton are selling have up to 1/8 run out. That's on new wheels manufactured today.

[CT AV8]

That's a neat tool but how does it compensate for runout? Don't the indicators mount at the rim?

[MrBruce]

No, it goes on the rubber tire and stays there while you move the car and it comes up in the back. Just like the Service Bulletin for front end alignment. I will take some pictures Saturday when I use it and put them on the forum. I think some people on the forum have used a shower curtain rod which has the spring action. It does say to "Press out on front of wheels to take up play" I guess that's the run-out compensation. We used to do it with a board, nail, and chaulk and it worked well.

[mshmodela]

For those who have not see the latest "Restorer" it has a nice article Front end alinement of a Model A.

[mccsix]

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MB do you have a p/n for the tool?

[Mitch//pa]

Originally Posted by mccsix

MB do you have a p/n for the tool?

i have the same tool
the part numbers are on the paper and the difference between the two are the overall length's

[bobusnick104]

The latest Restorer has a very good article by Howard Eckstein on the basics of wheel alignment. I haven't seen a better explanation.

[MrBruce]

MCCSIX, the smaller one that I have is #61600

[MrBruce]

Mitch, thanks for posting the pictures. I have it here in the office but didn't have the camera handy. Just starting to get used to posting pictures on the forum. Have you used it yet? I am going to do it today as soon as the temp gets a little warmer (looks like it's 53 now) should be close to 60 the next few days.

[MrBruce]

Yes, the Restorer has a great article, but for those of us who don't have a front end machine in our garage it's a lot of interesting info. But it's interesting to see the details of what went into the steering 80 years ago. We have a truck place not far from here who will check out Model A front ends for straightness and other dimensions, just haven't had a chance to check it out. I have six new tires to mount but need to paint the rims and probably put new tubes in after running them 30 years.

[Mitch//pa]

Originally Posted by MrBruce

Mitch, thanks for posting the pictures. I have it here in the office but didn't have the camera handy. Just starting to get used to posting pictures on the forum. Have you used it yet? I am going to do it today as soon as the temp gets a little warmer (looks like it's 53 now) should be close to 60 the next few days.

it gets it close but not nearly as accurate as my alignment rack... i set the toe to 1/16th in with the tool and the rack had it a hair toed out...

its not exact by any means acceptable?? yes....

[H. L. Chauvin]

If anyone is interested in making an alignment gage very similar to the Doby Gage shown above, made one about (3) years ago (1) as follows:

1. Main Horizontal Alignment PVC Strut: Cut a piece of 3/4" PVC pipe approximately 47" long.

2. Hidden Inner Spring: From a hardware store, get an approximately 3/4" diameter coil spring approximately 6" long. (Bring a piece of 3/4" PVC pipe to store to make sure spring fits & slides easily).

3.. Left & Right Wood Dowel Pin Holders:

A. Fixed End: Cut a wood 3/4" O.D. dowel approximately 34" long, insert wood dowel in fixed end of PVC pipe allowing 1-1/4" of the dowel to protrude on the out-side of the PVC pipe; then secure this approximately 34" long dowel in a fixed position with a 1/8" through bolt provided at approximately 2-1/2" from the fixed end of the PVC pipe.

B. Sliding End:

a. Sliding Wood Dowel: Cut a wood "sanded or shaved" 3/4" O.D. sliding dowel, (to slide easily inside the 3/4" PVC pipe), approximately 12" long, & with a Dremel tool, cut an approximately 4" long x 1/8" (+) wide slot in the longitudinal center of the dowel.

b. Insert the coil spring into the open end of the PVC pipe allowing it to rest on the inner, fixed 34"long dowel.

c. Drill a 1/8" centered hole through the PVC pipe, approximately 6" from the sliding end of the PVC pipe.

d. Provide a 1/8" through bolt through the PVC pipe & through the slot in the wood dowel so the slot acts as stops to prevent the dowel from sliding out of the PVC pipe, & from compressing the spring too far.

C. Steel End Pins: Drill an approximately 1-3/4" deep hole in the centered ends of both dowels. Cut (2) 12 penny, (12d) nails approximately 2-1/4" long & insert in the drilled holes in both ends of both wood dowels & allow approximately 1/2" of the steel pins to protrude outwards from outer ends of both wood dowels. With a file, provide slightly rounded smooth pin ends where end pins, (nails), will contact front tires.

(NOTE: All dimensions above will depend on the "trial & error" exact lengths of the spring, dowels, & locations of through bolts -- if doubtful, not a bad idea to get (2) dowels, one for trial, one for final. Nicer to provide bullet shapes on ends of both dowels so one can better see the position of the pins on the front tires.)

D. Provide & secure small chains on each end, dangling 6" from center of PVC strut to bottom end touching floor.

E. Wrap masking tape on sliding wood dowel, place tool on engine side & between front tires. With 6" suspended chains touching floor, mark tape at outer end of PVC pipe strut with a fine point black pencil. Roll car backwards approximately 36" until ends of suspended 6" chains contact floor again, & again mark taped wood dowel at end of PVC pipe with a fine point red pencil.

F. Remove tool to see toe-in dimension between red & black pencil mark.

[MrBruce]

Mitch
I tried it today (the tool), then before I could make any adjustments it started to rain. I couldn't believe how far off it was. Now I know why I wore out my last set of front tires so fast. It was off 1/2 in toe in, which would be 7/16ths off. Just a little to much toe in. I think a few years ago I used the chaulk and nail method with a board. Always worked in the past, but this time I think I did it alone and must have messed up. Tires are to expensive to wear them out like this. I have six new tires and will have to paint the rims before putting them on. After 30 years I think I will also put new tubes in.

[Mitch//pa]

Originally Posted by MrBruce

Mitch
I tried it today (the tool), then before I could make any adjustments it started to rain. I couldn't believe how far off it was. Now I know why I wore out my last set of front tires so fast. It was off 1/2 in toe in, which would be 7/16ths off. Just a little to much toe in. I think a few years ago I used the chaulk and nail method with a board. Always worked in the past, but this time I think I did it alone and must have messed up. Tires are to expensive to wear them out like this. I have six new tires and will have to paint the rims before putting them on. After 30 years I think I will also put new tubes in.

well as far as tubes some will say if they dont leak use them. the tubes on the market leak, so if you go that route buy them from Brattons... he has them specially made to spec and is the only one selling them to my knowledge..

[MrBruce]

I have to cut the stem and put the metal valve stems in so was going to be around Smith & Jones, SC. I normally buy from Walt, but thought that since I needed to pickup parts for our spring tune up I would save some freight. Do you think there is a difference in quality on the regular tubes? Walt mentions in his catalog 100% new rubber not recycled rubber.

[Mitch//pa]

yes there is a difference
he sells them with metal stems installed also

[MrBruce]

Yes, I was going to do that until I saw the price. Close to $50.00 a tube and I already have the metal valve stems and did them years ago (never had a leak) which is surprising. I think both of them are selling the regular tubes for the same price so I will go ahead and get them from Walt. He supported us well for our MARC business meeting with ad money so try to support these guys.

[H. L. Chauvin]

FWIW:

Before discarding old inner tubes, it may or may not be good to know that I have some tubes in the 1955 Chrysler tires on my homemade boat trailer that still hold air.

Forgot what brand tubes, but my guess is they were made here in the U.S.

They were bought & installed in 1960, i.e., 54 years old, & still holding air.