Alignment issue 31

[old31]

What would cause this?

For a while, my roadster has been pulling slightly to the right. It is more noticeable the faster I go.

I noticed that the right front tire has been wearing out on the outside edge. I changed that tire to the left rear. I have radials.

I changed the toe in to 1/16 and the pull got worse. Then to 1/32 and that became worse.

I then changed it to 3/16 toe OUT and it got better, but still with a very slight pull to the right.

I have never had an issue before with 1/16 toe in.

[Will N]

Bent axle, worn out tie rod end, wheel bearing too loose or worn out, worn king pin bushings, underinflated tire.

[Jim/GA]

It is very common for the front axle to be bent on the right side, outside of the spring perch, due to a driver in the past hitting something when running off the road. There is no simple fix. You have to remove the axle and cold bend it back straight. Or replace the axle.

[arnhemmer]

I had the same problem with one tire wearing extremely fast. It also pulled to one side. It turned out to be a bent tie rod due to hitting an extremely large pothole. I replaced the tie rod, lined everything back up which solved the problem.

[Synchro909]

I'll add to this just like arnhemmer. My Phaeton wore the left front tyre too rapidly and I guessed it was a bent axle. I hade it straightened and the king pin eyes shrunk back to the right size. No problem since and driving was transformed. Here, it is the left side that gets a hard time along the edge of the road, unlike you guys so we are talking about the same thing.

[Will N]

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I had my bent axle straightened by an old timer's alignment shop while it was still on the car. Not may of these shops left around any longer. He had a pit that you drove your car over and the front axle could be chained down at the pivot point where the unbending had to occur. He used hydraulic jacks to unbend the axle to get the camber correct. He used a long bar with some kind of clamping mechanism to twist the axle to get the caster right. Then he set the toe-in using a gauge you had to drive your car over to measure it. He has since close up shop. But my friend found a truck alignment shop that worked on his. They're used to dealing with beam axles.

[nkaminar]

My Model T had a bent axle. It had the wrong caster (not enough) on one side. I bought a 6 foot pipe wrench, wrapped aluminum around the axle where the wrench attached, and lifted the end of the wrench with a floor jack. The front end of the Model T came off the ground. That procedure straightened the axle. The axle on a Model T is not as beefy as the ones on Model A's. It may be possible to do the same thing on a Model A with a special wrench that was 10 or 12 feet long. Someone with a cutting torch and welder could probably make one.

[JayJay]

When I took my '30 TS apart the axle was bent right side rear and twisted, and the right side of the frame was pushed rearwards. The right wishbone also had a slight curve inwards. All of this is consistent with right front hitting something hard (not unexpected in a 90+ year old car). I cold straightened the axle back with a hydraulic press, a pipe wrench and a long cheater bar, and straightened the wishbone, but could not get the frame to true up (it had other problems as well), so I ended up replacing the frame with a straight one.

Surprisingly, the RF fender and associated sheet metal is pretty good (minor tear where it joins the running board).

[old31]

Other than using your eyes, is there a tool or gauge that determines if and how much the axle is bent?

[Bigsnapper43]

Yes there is a tool. Bear company made it in the '30s. I have one. I have one problem is I'm in Eastern Ohio.I found it in an old repair shop.

[Dave in Petaluma]

One of our club members made a set of alignment dowels that fit into the spring perch and kingpin holes of a removed axle. It's not difficult to correct a bent axle with a shop press using the dowels to sight across.

[JayJay]

There is bent and there is twisted.

Bend can be roughly determined by using a long straightedge and sighting along the kingpin and spring perch bosses on the front/back of the axle. It can be corrected using a shop press. I have used a 20T press but I suspect a smaller one might work. I set a piece of 1/4" plate on the plates where I want to press, rather than pressing on the web.

Twist can be determined by the use of winding sticks. I made a couple of sets from 1" stock with a taper on one end of each, and a 3/8" hole down the center. Mount a length of 3/8" cold rolled through the holes, and mount the tapered fittings into each of the kingpin and spring perch bosses so that the cold rolled extends upwards. You then sight along the long pieces to determine if they are lined up. A proper axle will have all four pieces in the same plane. You can use a piece of string to check how close they are.

Here are a couple of photos from a seminar I put on for my club a few months back.

The tapers require that the front axle be completely disassembled - including kingpins and spring perches removed (the latter is not always a straightforward proposition). I also made a set of adapters that clamp onto the front axle on the outside and use the same long rods, but I don't think they are as sensitive as the tapers. You can use those clamps on an axle that has been removed from the car but is otherwise still assembled.


Old31, if you're anywhere close to me (San Francisco Bay Area) I'd be happy to lend you my winding sticks and tapers.

[old31]

Thank you, JJ. But I don’t think Florida is that close to San Francisco.

[JayJay]

Originally Posted by old31

Thank you, JJ. But I don’t think Florida is that close to San Francisco.

No, it's not. In so many ways...

[old31]

That's correct. We don't have the Golden Gate Bridge

[JayJay]

Originally Posted by old31

That's correct. We don't have the Golden Gate Bridge

Or the London Bridge. Of course, neither does California. It's in Arizona.