I took the 26 Roadster for a short ride yesterday. Less than a mile. Everything went good for the first minuet. I don't think I went over 20 mph. About 30 seconds into the drive the front end shook violently. I brought the car to a stop and turned around and headed back. Took the car up to about 30mph and on a longer stretch of road and it drove very well. Im now afraid to drive the car until I find the cause. If that front end problem would had happened on the main road and at 35/ 40 mph it would had killed me. Yes it was that bad! It felt like it was trying to lift the car. The work I did to the front end was new spindles and bushings, Tie rod bushings,cleaned and repacked all the wheel bearings and installed new seals. What do you guy feel it was?
Did you get the radius rod tight? Bud.
Alignment! check it twice. Mine did that until someone pointed that the "Gather" was wrong
Did you check the king pins to make sure they are tight on the axle. You could have a worn axle.
My dad told my mom 'they all do that'. ;-)
... until I found out what wheel bearings, steering linkages and worn spindles do!
Check everything on the front end from the steering wheel to the wheel bearings. The spindle bolts and bushings must be snug on the axle. You can jack up the wheel and putting one hand at the top and the other at the bottom, move in and out. A loose wheel bearing will be noticeable, or loose spokes. Rotate the wheel and see if the rim is in alignment or whether it moves in and out as you spin the wheel. Up to 1/4 inch is OK, more than that is a problem. You can also check play in spindle bolts in the same way. Then move your hands to front and back of wheel and check for play in the tie rod between the wheels. Here too it must be snug. Then with the wheels on the ground have a friend turn the steering wheel back and forth through the free play. Look at the drag link between the two ball joints and see if it is loose at one or both ball joints. Also check the pitman arm on the end of the steering shaft. It should be tight. Also check the spindle arms. They should be tight in the spindles. The bushing in the lower steering bracket should not have noticeable side play. Check also the ball joint where the radius rod is fastened to the crankcase. That should also be snug.
If all the above are good and it still shakes, measure the tow in. This can be done by placing masking tape on the front edge of the tire perpendicular to the ground. That is use a framing square one leg on the flat cement floor and put the tape at the place where the other leg of the square touches the front edge of the tire. Then measure the distance between the two wheels and mark that spot. Then push the car forward or backward until the tape is in the same position at the back edge of the tire and measure. This way of measuring tow in will eliminate differences caused by slight deviations in the spokes. It should be 1/8"-1/4" wider in the back than in the front. Usually there will be only one rotation of the tie rod end where it meets that length and you will have to live with it.
Other alignment adjustments are castor and camber. These can only be adjusted by bending the axle. The castor can be changed somewhat by frame alignment if the frame sags in the center which most do. So fix the frame before you bend anything.
There is also wheel balance You can tell how well the wheels are balanced by jacking up the wheel and spinning it. Note where the wheel stops. If you turn the wheel about 3/4 turn and let go, it will move to the same place and stop. If so, you need to add some weight opposite the lowest place where the wheel stops.
It has been my experience that the T wheels are light enough weight and the car is slow enough that balance is usually not the cause of shimmy. Usually shimmy is caused by some loose part. If you hit a small bump the wheel will shake and the shaking will set up a harmonious vibration and keep on shaking. Sometimes the only way to stop it is to stop the car and start out again. Usually if you drive either above or below the speed which the shaking starts, it will not shake.
The tow in is more likely to cause the car to wander. In that case, it will pull to one side and when you try to correct, it will pull to the other side and be hard to keep going in a straight line.
Hope this is helpful and that you soon find and correct the problem.
In Norm's instructions above, I would always roll the car forward, as any wear on the steering stuff will be taken up in the direction of travel (does this make any sense, it's not writing out like I thought it would).
Also, make certain your spring bolts (to the frame) are tight and the center bolt is intact.
Mine had the DEATH SHAKE when I got it. Someone left the cotter pins out of nuts on king pins. Tightened and installed pins and had no problems since.
If we are just talking about front end shimmy, then any amount of play anywhere in the system can allow it to happen. Fortunately, it only occurs within a narrow speed range (One of those natural resonant frequency things), like say just after turning a corner, It's annoying, but I usually just accelerate through it. It goes away if you increase speed. If it's something else, forget what I just said.
SHIMMY! Been there on more than one Model T.
Get a helper. Move the steering wheel back and forth an inch or 2. While helper is wiggling the steering wheel get under the car with a good light and look and feel for ANY (did I capitalized that?) looseness or play anywhere in the steering system or linkage. If you find ANY slack- fix it.
Then, jack up one wheel at a time. Grab the lifted wheel at the top and bottom- push and pull. If you have any slack at all, then the kingpin needs to be replaced and probably the bushing at the top as well. Sometimes the threads at the bottom of the axle where the kingpin screws into will need to be reworked too.
Excessive wear at various points in the steering column can also cause shimmy.
My hack got the shimmy when I hit a bump and there were passengers in the back. There was a little play in the kingpins so I replaced them the bushings, and one tie rod end. The rest seemed tight.
I haven't had an opportunity to ride with a load in the back but it seems tighter.
The first thing I will do is rebuild the entire front end. If that dosent cure the problem I will move to alignment. The right wheel is bent but not more than a 1/4 inch out of round. I might send the front wheels out to Stuzmen's for respoking just to eliminate that possibility.
Rusted, seized spring shackles?
Years ago my '27 touring did that. I worked on everything on the front end and nothing helped. One day I noticed that the front tires had more tread on them than the rears. I swapped them and the problem went away. This car has stock wire wheels. All of the tires have been replaced since then and the problem has not returned.
Will did you have the axle out.Check the castor it is easy to put the axle in backwards there by putting a negative caster which will give your symptoms cheers pete
Mine did this until I found the wishbone was loose where it bolts to the front axle under the spring perches. I tightened the two nuts and it has been fine ever since. Brad.
My rpu had worn king pins and had problems like that. Rebuilt and no longer have a issue.
yes ALL looseness needs to be checked and taken care of. BUT THE MOST IMPORTANT THING WHEN THIS IS DONE,to check the toe in.... and set it to the correct setting for you car,GREG.
Yes, gather (toe-in) is important. Even if it doesn't cause a shimmy, bad alignment can eat up those front tires in a few miles.
All of the recommendations regarding looseness are well founded. Please do heed the suggestion made by Dave Dufault regarding the front spring shackles, if one of the four points does bind it can (will) cause a serious shimmy when the car hits a bump; railroad tracks can be especially bad.
I have experienced this myself in a car with a rebuilt front end. Good luck with your project, Bill.
Will, this thread is timely for me too.
Over the weekend, the 18 Runabout found a spot in the bumpy driveway that gave it the Shimmy Shakes in both directions on the road at about 15 MPH.
Only went Shimmy Shaking with an adult or two in the car with me.
Reset the toe-in (bad toe-in!) and now am trying to get it to do it again.
The issues I know of on mine are the axle itself needs a Steven's type rebuild (bad threads on the bottom and upper holes are garbage).
Until I find any more looseness, I'm saying the front end is pretty tight yet I need to check the steering bracket bushing plus the pitman arm.
The planetary gears are not perfect but I sure couldn't hold it with the steering wheel. Had to slow down a bit or hit another bump.
More things to check for me. I do have a sluggish front spring shackle 'tho and I lubed it again plus gave the spring some lube.
Thanks for bringing this subject up again Will! Keep us updated! :-)
My newly acquired '23 runabout has this malady as well. It has done it twice now, both times just as I was pulling out of a parking lot. Haven't had time to look into it yet. Seems such a common problem should have a name like "twobbles" (it wobbles) or "wobblltees". I'll bet the great forum punster, Richard Eagle, can come up with a good one.
I had this problem, too. Popeye came with accessory springs that fit over the ends of the tie rods to dampen vibration. They worked so well they masked vibration until one day when the shimmy literally took the steering wheel out of my hands. Fortunately, I was only travelling about 10mph and was able to stop.
When I took the front end apart I discovered that the bushings on the end of the spindle arm were totally wallowed out. Had there not been a washer on top, the bolt could have simply dropped out. This was masked by those accessory springs until the problem hit 'critical mass'. These are the springs I am talking about:
Of course while the front end was down I rebuilt everything, but I am convinced those springs masked a problem that could have ended much worse for me...
Its going to take some time before I can get to it. Got to save some $$$ so when I start the project I will have everything to work with. I will replace everything, All the bushings, Take the springs apart and clean and relube with spring paint, Replace with APCO on the wish bone and steering linkage. And then do the rear springs and bushing also. I got big plans for this car. Iv always wanted a Roadster so this car will get the Warford transmission. About the time I get everything done I want done on it the wife should be retired and we can do some traveling in it. Im really thinking about going with wire spoke wheels, I think they would set the car off real nice.
No need to rebuild the whole front end unless you find almost everything is loose. Sometimes it is just a loose nut on the spindle arm or a loose ball joint which can be fixed easily. So do some tests first before you rebuild.
Norman, I know but if I rebuild everything then I will have the peace of mind knowing that it's right other wise I would alway wonder if it needs repairingp