We have rebuilt the front axle on our 1912 touring Nos axle checked for straightness every thing good. New tie rod bolts and bushings new king pins bushings reemed with our stevens tool all good,all the balls on all the steering and tie rods are good. The ball and socket at the panare good no play. New roller bearings and set adjusted correctly. On the highway 25 miles an hour all is good,when I slow and get into a little rough road, I get a flutter or wobble. The perches are installed correctly we built Steve tool and set the toe in at 3/16. I am at a loss as to what is wrong. The old axle was bent and twisted but never did this. I need help Cheers Colin
Colin, the next thing to check is the caster. This is the angle at which the kingpins should lean backwards. If your radius rod positions the axle with too little caster, you may well get shimmy. When setting the caster it is achieved by bending the radius rod. The old timers used a LARGE bar to achieve this. It is better to have a bit more Than not enough. More will make it a little more skittish when reversing.
Hope this helps.
Allan from down under.
Thank you Allan I though if your axle was straight when you install the radius rod that is what set the caster, There are no bends in the radius rod. I will have to check the angle. Thanks again Colin
It took two guys on a 4 ft pipe wrench to get the caster set correctly on my 25 coupe. If I were to do it again, I would probably use a little heat on the end of the radius rod. But that's just me. Some say you should not use heat.
This might help:
If you check and find you have very little caster, before you resort to bending the radius rod, remove it, flip it over and the reinstall.
I have a number of early radius rods and have found if they are laid on a flat surface, the prongs are typically slightly bent in the same direction.
You are right Colin. The radius rod does set the caster. However, after 103 years there is every likelihood that it is no longer true to original specs.
Allan from down under.
Easy to putthe early radiouserod in upside down
The othere thing i found is wear at the radiouse rod ball and pan
If wear is there the angel will be less
Before you start bending things check to make sure that you don't have a front shackle that is stuck. If a shackle is not swinging free and is stuck at either pivet point it causes the car to shimmy on rough roads at slow speed. What happens is that one shackle will pivot normally but the other one does not so when you hit a bump it is like some large force is shoving the front end to one side and that is what causes the steering to flutter.
Put a floor jack under the center of the front axle and raise up the front end rather high and put jack stands under the frame near the front on both sides then lower the jack to "hang" the front axle by its shackles. As you lower the front axle it should come down nice and smooth and even on both sides. If one side hangs up you have likely found the problem. It should also go back up nice and even on both sides as you jack it back up to remove the jack stands. Check this out and also make sure that you have a very slight "drag" on the king pins by a gentle snugging of the king pin and then the lower locking nut. NOT tight but just a wee bit of drag when you have the king pin lower locking nut in final tight position.
John, you have me thinking. On my speedster we fitted a shackle lock to one side of the car on both front and rear springs, just so the car cannot swing from side to side on the shackles. It works a bit like a Panhard bar.
Anthony made the front one and I thought it looked a bit agricultural, so I made another like the rear one. With his agricultural one the car steered really well. With my new one we have a pronounced shimmy! I can drive through it, but there are occasions when this is not advisable. My next trick is to loosen the bolt through the spring eye so there is a little give there. If that doesn't work it's back to Anthony's idea, with a little cosmetic refinement.
Allan from down under.
Just finished fixing one with a problem similar to this and worse. We checked all the axle parts out and the entire front end was fine. What we found was, one of the pins in the steering shaft was loose and the gears were wandering. Made the front shake and wander all over the road at lower speeds. Just something else to think about.
Just a thought. I almost wrecked my 1911 torpedo going around a corner that was banked at about 20 MPH. It tried to rip the wheel out of my hands and I have hands. Front end was tight but the radius rods had an ever so slight bend in them. I straightened them out but still had problems. A friend of mine (a true model T guru) gave me a correct accessories radius rod Thad mounts to the bottom of the axle and stops the caster changing after hitting holes or banked corners. Simple to make. Even Henry wrecked one due to this problem. I've never had a problem since and the Torpedo steers perfect. Check out Henry Ford crash and you'll see what I talking about.
I can't locate the information about "Henry Ford crash".
Would you have time to post a link to the details please?
Good evening gentle men after reading all the comments we have come to the conclusion that this weekend Dad an I will start from scratch, go through all the parts and do and check every thing that you guys have mentioned. We have doubled up the wish bone so the axle is solid, as for the rest we will have to check everything. Thank you All and I will get back on this weekend and let you know what we have found and if it has been fixed. Cheers Colin
Dave, you can read the story about the crash due to an early wishbone involving Henry Ford in the 1955 book "Tin Lizzie" by Philip Van Doren Stern. The story has been posted on the forum - you can find it by googling "Tin Lizzie Stern wishbone MTFCA".
Here's one of the threads where you can read the story as it was told by Joseph Galamb in the 50's:
Thank you Roger.
(& you also Richard, for drawing attention to it).