Please tell me what to do to stop or reduce front wheel, steering shimmy in our '23 fordor sedan. At low speeds steering wheel and front wheels often shimmy so violently that I must come to a complete stop in order to recover. Please start with front wheels and guide me all the way up to steering wheel with tips about what I should do to reduce or stop shimmy. HELP!
I would check alignment first.
Repair all loose parts including the radius rods (wishbone) spindle bolts, spindle arms, pitman arm and all ball joints. Include the tie rod and spring shackles and the gears within the steering gear box at the top of the steering column. Also check, grease and adjust the front wheel bearings and check your wheels for loose spokes or wobble. Fix wobble if you find it. Then make all alignment adjustments according to the book.
After doing all of the above, your shimmy might be fixed.
Here are some earlier threads on the subject:
My 1924 touring / pickup conversion had a mild shimmy problem when I bought it. After checking for correct front wheel alignment and bearing adjustment (both were fine), I found that the front spindle bushings were worn and I had a small amount of play in the ball caps of the steering drag link. I replaced the front spindle bushings and filed the drag link ball caps to remove the play and the shimmy went away and has not returned.
The steering dampers that the vendors sell do work, but as some have mentioned they mask the problem caused by improper alignment, loose/sloppy bushings, and worn components. It's best to fix the alignment and worn component issues first, my experience is the shimmy will disappear without having to resort to the use of a steering damper.
I had a rear tire cause a violent shimmy at the front on my 1916 Touring Car. Turns out the left rear tire was failing at the clincher and this caused the whole car to shimmy. Originally I thought it was a front tire problem but could find nothing. Then when adding air one day, I noticed the left rear starting to separate. Changed that tire and shimmy gone.
Worn wishbone ball... Add a shim and see if that helps. Easy fix and If it doesn't help, you're not out much.
R D Ricks put a steering damper on his T but he drives it rather quickly with his Frontenac engine. Perhaps he will read this post and tell you what parts he used.
Shimmy usually is caused by something completely wore out. It can be aggravated by incorrect toe in and / or incorrect caster. All the parts and labor to rebuild every part of the front end are cheap and easy respectively.
Steering damper just hides wore out and mis-adjusted stuff. The car probably handles poorly too, but you won't realize just how badly until the worn out or mis-adjusted stuff is fixed. So often you see a Model T that has been restored cosmetically but has serious safety issues from exactly this kind of thing.
Fix the problem, don't mask it or you might find yourself upside down and then hospitalized or worse.
I agree with Royce. Repair all worn components and check the alignment. A "T" with these in good order does not need accessory parts to have a well behaved car.
Be sure your perches are correctly installed on the correct side! If the axle is installed backward it will shimmy uncontrollably.
The short term fix is to give the front spring shackles a good oiling. The longer term fix is a complete front axle overhaul.
Also, when you do the overhaul, be sure to have the axle checked for straightness. You can not judge by eye whether the axle is twisted or bowed.
Lifting the front axle and wheels by putting a floor jack under the middle of the front axle is sufficient to bow the axle, which throws the two Front spindles out of alignment.
Model T front axles are tough to break, but they are surprisingly easy to bend.
I hesitate to mention this, as it is NOT the cure to your problem, but I have found speeding up gets rid of shimmy quicker than slowing down. I chased shimmy in my TT. I replaced all the worn parts which certainly lessened the severity and frequency (How often it occurred, not how quickly it shook), but I still get it occasionally, like say when I slow to turn a corner then hit a bump as I turn onto the new road. When this happens I just accelerate through it. It goes away. When I slowed down, it just got worse. You felt like the whole truck was going to shake apart. Speeding up is quicker. Of course, it would be best if it never happened to start with, and I certainly recommend you look into all the things others mentioned above. But if fixing everything mentioned results in still having the occasional shimmy, try powering through it.
Been there, done that!
Toe in alone won't cause a shimmy problem unless there are badly worn components in the front end.
Check EVERYTHING in the front end. Spindles, perches, drag link connectors, steering bushing, wheel bearing preload, steering arm, etc (probably not a complete list).
I did this by carefully watching (and feeling) all the above while turning the steering wheel from side to side. You WILL find loose joints. When you fix them, test again and you will find more. And ... it will fix your shimmy!
Its really easy to diagnose if you take your time and be observant.
What you've got is dangerous. Fix it!!!
My car came to me with accessory springs that "compensated" for the wear at the tie rod ends. I replaced one tie rod end bolt and that solved the shimmy problem so I removed the compensating springs.
Now that I'm going completely through the front axle, I found that both steering arms were turned a little so their bushings were not vertical which took up slack with the worn tie rod ends bolts.
In addition the spring perch threads were undercut so the cone shaped nut would not fit. A regular nut with a cone shaped washer tried to hold the axle tight to the front wishbone but without much success. I can even see weld marks on the wishbone eyelet where someone presumably tried to weld it to the axle since it wouldn't keep tight with the washer/nut setup. This is on the right side where the nut fell off once making the steering kind of squirly. That's what I said at the time, then I made a right hand turn and all of a sudden the car did a 360 degree turn on its own radius, as if a pole were pushed vertically through the car at its center. After the "wild ride" stopped we got out only to find the right front wheel was underneath the car! After pulling the front axle forward into place, a piece of wire through the cotter pin hole in the spring perch held the wishbone up. This got us home (a couple of miles) after I got up the nerve to take the wheel again. Fortunately this occurred at very low road speed on lightly gravelled road and no traffic around.
Just compare the thread size and pitch.
I'm really looking forward to driving a T with tight steering!
And I'll put in a word here for the MTFCA axle book. Follow that, and Bud's advice to be observant, and all should be well.
Steve, I just got my book last month. Got some reading to do!