front wheel shimmy.

[nickyboomboom]

I have a question about the steering gear box. When the front is jacked up and on car Jack's i can move the tires in and out . The Pittman arm moves back and forth . I can't seem to be able to make any adjustments that do anything. I live near lockport. Illinois. Where can i by a 2 tooth gear box at have mine rebuilt. A 1929 model a , 5 window coupe.

[Big hammer]

Welcome to the ford barn! At the end of page3 or 4 title steering wheel shimmy someone posted how to adjust steering box ( model basics ) every good reading

[1crosscut]

Lots of things can affect the steering. First off make sure the steering box is tight to the frame and then tighten the bolt that holds the steering arm onto the shaft from your steering box. You do not want any play in this connection.

Next get a helper that will be willing to sit in the cab and move the steering wheel back and forth for you while you crawl under the car looking at absolutely everything that moves. What I mean by turning the wheel back and forth is to turn it just far enough that it doesn't actually turn the wheels but "bumps" the wheels just short of turning them. The person moving the steering wheel needs to be patient sort because you need to take your time to eyeball everything very carefully. Starting at the steering box look for any slop or looseness. Just a little bit here and there can and will cause troubles.

Some of the things to look for:
Movement in the ends of the drag link and tie rod ends.
Movement at the rear of the radius arms where they merge together and attach to the bottom of the bell housing.
Worn king pins.
Front wheel bearings loose.
Front spring clamps loose where the spring is attached to the frame.
Brake backing plates not tight.
I'm sure others will jump in with stuff I've missed.
After you get all of the play out set the toe in.

[nickyboomboom]

Alright Dave, you have given me a lot of good info. I will be working on that problem this weekend. I will get back with what happens thanks for taking the time to respond.

[Mike V. Florida]

As Dave has mentioned EVERYTHING that attaches the front end can be a part of the problem. Think about how many connections there are between all the parts. A very small amount of play in each can add up real quick.

[nickyboomboom]

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Thanks i will be checking that out.

[MikeK]

I'm a bit confused about the title of your post "front wheel shimmy" and your leading sentence "I have a question about the steering gear box." Replacing your 7 tooth with a tight rebuilt 2 tooth will NOT address the primary cause of wheel shimmy.

Shimmy is a result of less than spec caster. Stiff shocks and tight rebuild of everything in the front end will not make it go away if you have a bent axle, bent forgings at either end of the wishbone, engine misalignment (the wishbone bolts to the fly cover casting at the back) or frame twist and bend. These are the primary culprits in an "A", and simple visual inspection likely will not reveal a bend of only a degree or two. You need to carefully measure.

Even a car with sloppy kings and balls will track straight without shimmy if there is sufficient positive caster as shown below. 80 years of pounding pot holes and RR tracks bends both the axle, shackles, and wishbone in the negative direction. Reducing caster 2 degrees on an A will drive it into a wild shimmy when only one wheel encounters a dip or hole, even if you have new, tight everything in the front end. Think of a shopping cart. When the front wheels get slightly bent back from slamming curbs and parking lot divots, you get a cart that shimmys.

There is a lot of info out there about how to straighten an A axle, but not much about the wishbone. The front forgings that hold the kingpin actually bend rather easily compared to the axle. Perhaps someone has the ford print for the wishbone and can throw in a few angles and dimensions?

There is really no mystery. If it shimmys something is usually BENT. Tightening everything up to new spec certainly improves steering and tracking but does not address geometry errors that induce resonance like shimmy.

[Tom Wesenberg]

We need a better description of "the front wheel moves in and out".

Moving in and out would usually mean very loose wheel bearings.

Rocking the wheel in a vertical plane would mean worn king pins and bushings, if the wheel bearings have no play. Grab the tire top and bottom and pull the bottom out and push the top in. This is worn king pins and/or bushings.

Rocking the tire back and forth in a horizontal plane would indicate loose or worn steering parts. Grab the tire front and rear and rock it back and forth to look for slop in the steering parts.

[BILL WILLIAMSON]

Originally Posted by 1crosscut

Lots of things can affect the steering. First off make sure the steering box is tight to the frame and then tighten the bolt that holds the steering arm onto the shaft from your steering box. You do not want any play in this connection.

Next get a helper that will be willing to sit in the cab and move the steering wheel back and forth for you while you crawl under the car looking at absolutely everything that moves. What I mean by turning the wheel back and forth is to turn it just far enough that it doesn't actually turn the wheels but "bumps" the wheels just short of turning them. The person moving the steering wheel needs to be patient sort because you need to take your time to eyeball everything very carefully. Starting at the steering box look for any slop or looseness. Just a little bit here and there can and will cause troubles.

Some of the things to look for:
Movement in the ends of the drag link and tie rod ends.
Movement at the rear of the radius arms where they merge together and attach to the bottom of the bell housing.
Worn king pins.
Front wheel bearings loose.
Front spring clamps loose where the spring is attached to the frame.
Brake backing plates not tight.
I'm sure others will jump in with stuff I've missed.
After you get all of the play out set the toe in.

Yo' Dave,
"SOMEWHERE" I tiped GURU Claude's inspection system, that he learned from the FORD TRACTOR Safety Inspection. It's much like what you have written. You gotta' have weight on the wheels for this inspection & LOOK at & FEEL each part.
You gotta' put the SKINNY guy UNDER the car & the BEER BELLY, in the car
Sadly to say, GURU Claude passed away recently, at 86 years old. I could write a book about him, He was one of the FINEST men that I EVER knew. I BARELY qualified to be his ASSISTANT GURU OF STUFF!
Bill W.
Bill W.

[HoarseWhisperer]

As mentioned, many things in the front end can contribute. Shortly after acquiring a 28' Pickup, it developed the "death wobble". Noticing a bit of king pin slop, I replaced them, but it didn't help. Measuring caster; it was off. Discovered it had one of those after market rubber thing-a-ma-bobs for the radius ball. Changed to original design; no more shimmy.

[Jacksonlll]

You must have the to-in set properly. It is critical for shimmy.

[SeaSlugs]

Originally Posted by HoarseWhisperer

As mentioned, many things in the front end can contribute. Shortly after acquiring a 28' Pickup, it developed the "death wobble". Noticing a bit of king pin slop, I replaced them, but it didn't help. Measuring caster; it was off. Discovered it had one of those after market rubber thing-a-ma-bobs for the radius ball. Changed to original design; no more shimmy.

this is also a critical point to look at, alot of times this ball is worn and or assembly is loose this allowing the entire axle to shimmy around. Jeeps tend to get a "death wobble" for similar reasons.

but yes any slop anywhere in the front end can cause weird vibrations that can attribute to a wobble, even if you replace the worn parts and the shimmy is still there your still fixing issues that need addressed.

[Mike V. Florida]

Originally Posted by nickyboomboom

I have a question about the steering gear box.

When the front is jacked up and on car Jack's i can move the tires in and out . The Pittman arm moves back and forth.

Does the steering wheel move when you do this?

If yes, that tells us nothing
If no, then your box needs rebuilding/replacing, how much play do you have in the steering wheel before the wheels move?

I can't seem to be able to make any adjustments that do anything.

Please give us examples of what adjustments you have made. Did you follow the 2 tooth steering steering adjustments?

I live near lockport. Illinois. Where can i by a 2 tooth gear box at have mine rebuilt. A 1929 model a , 5 window coupe.

Snyders does it;

http://www.snydersantiqueauto.com/504

[Jacksonlll]

If you can find a local model a club near you, you should join it. You get a lot of good help from a club.