Because your Model T is not screwed together right.
Ford used a variety of steering connector rods (Drag Links in modern parlance). If you have one installed that is too short or too long you can have problems. Here's the record from the encyclopedia:
STEERING CONNECTING ROD
Factory Number T-289
7-29-12 Riveted rod adopted. Brazing pin holes at various angles.
11-4-12 Pin holes now drilled in the same direction.
1-9-14 Both ends of brazing pins riveted over.
9-19-14 Length of rod changed from 30-11/16 to 30-11/1630-3/4. A month later it was changed again to 31.06231.125
7-14-16 Ford design with forged end adopted. Earlier type continued in use (supplied by outside firms).
5-8-17 Ford design now used exclusively.
10-2-17 Length changed to 30.93831.062.
5-19-19 Length changed to 30.31230.438
Factory Number T-289-B
At the introduction of and for the 1926 models, the length was 31.12531.250.
10-7-25 Length changed to 30.81230.875.
A few examples in my garage to illustrate the differences. The one on the left is about 1" shorter than the center one. The one at the far right is about 1/4" longer than the center one. Overall about 1 1/4" difference from shortest to longest, and I don't own every variation.
However, most T owners are unaware that there is another steering component difference that can have a huge effect. The tie rod!
The tie rod is barely mentioned in the encyclopedia. Obvious differences are seen in the pre - 1920 tie rod having an integral ball on the passenger side of the car, and the adjuster on the driver's side.
The tie rods from about 1920 on have the adjuster and ball on the passenger side, with the ball a separate part.
Most importantly the LATE (early-correction posted by Chris per comment below) tie rod ball is about 1 1/2" closer to the steering column. Look at the picture below, these rods are identical in overall length.
This can cause huge trouble if you have the later tie rod in an early car. Your steering will go over center, and you will not have full travel in each direction.
Here's another problem that you may be unaware of:
You need to have a compatible set of steering components in your Model T or you will have a dangerous vehicle. Not only should the parts be of the same era, they need to be in good condition, installed properly, and adjusted correctly.
You don't need anything Ford did not design to have a safe car, except to drive as if the car is 100 years old.
Thankyou for an excellent thread---I`m motivated to check my early fords for consistancy(and correctness) in the steering components! Paul
In the later steering columns one of the three planetary gear pins is longer, extending thru the steering shaft and riding in a arced groove in the bottom of the steering ring gear housing. On my 27 coupe the long pin was not there. When I rebuilt the steering column, I installed the longer pin and my over center problems vanished.
Thanks, Royce for the excellent information. I would also say that any of you speedster guys should also check everything out close. You can run into problems when you lower the steering column, friend of mine had that to happen, could have been fatal but we caught it and fixed the problem. Have fun, be safe, KB
I think that this should be a mandatory thing to check, and be added to the touring checklist. Too many T's are running around with mismatched parts on the front ends. Great info Royce, I just went and double checked mine.
On RHD cars there are more differences.
Not only those Royce has noted but with the introduction of the Electrics the generator was now in the way of the bottom steering shaft bracket on the chassis. So the steering column was tilted to the left side and a redesign of the bracket was made to hold the end of the shaft under the generator this moved the shaft over nearly 1 1/2" to the right.
If you have all the right bits the Pitman arm must be vertical with the wheels straight ahead and when you move the front wheels from lock to lock the pitman arm must not be so far over the connecting rod is able to be pushed up past horizontal
Excellent posting, Royce! Thank you.
Drive carefully, and enjoy, W2
Thanks Royce, very important thread.
Royce's advice about Model T's being a 100 year old car is always good to remember. Especially when driving one.
Whoda Thunk ? Great stuff Royce!! many thanks for your eye opening post!
There's a typo in my post. It should say:
Most importantly the LATE tie rod ball is about 1 1/2" closer to the steering column.
On my 26 I found some barnyard mechanic over half a century ago installed the steering gear upside down and install a longer pin on one of the planetary gears to fit in the grove. The result was that it over steered one way a steered short the other way. Then the drag link was too short, the caster was backward, the steering column was shortened 3" and the steering gear was solidly brazed to the column (un-removable). I don't know if there could have been more wrong with it but I have repaired most and have parts to fix the rest.
Excellent information Royce. Thank You!
Thanks for adding to the tribal knowledge, Royce.
My second day with the Speedster, in 1997, I drove out a driveway, turned the wheel sharp, and it went over center into steering reversal, and whipped me right back in a U and jumped the curb. I quickly figured out what it was doing, and went in a vain search of a longer pitman arm.
It wasn't until later that year when I was installing a frontend with double wishbone and brakes, that I discovered the spindle arms had been lengthened, to make for slower steering. That's what caused the over-center steering reversal. I still have those customized spindle arms somewhere. I should cut them up.
I gradually upgraded the steering over the years with a steering damper, and then 5:1 gears, and later 10:1 from a '37 Ford.
It would be nice to have a frontend diagram for each series of years, showing all critical dimensions of the steering and suspension.
Ralph, you must have been reading my mind, have been working on trying to post some numbers.
Here are a couple of pictures to start. One of our club members Robb Wolff did an article a couple of years ago on this very problem. It probably should also be done in the vintage ford.
Link to the complete article in our newsletter
Drag Link Lengths
Data compiled by Robb Wolff
This information is clearly important, and I 'm sure I'm not alone in feeling most appreciative of the efforts of the few really knowledgeable folks.
From my perspective, though, I still have a problem understanding all this information. I have just one car, a '12 Touring, and don't have any extra parts to compare. When someone says, "small bracket" versus "large bracket", it's hard to know which one I have when I don't have anything to compare with.
This is not meant to be a criticism of what you guys have done so far, just an attempt to give you the perspective of an individual owner.
Thanks for all the good work,
This has been a very interesting thread. I did find this 2007 thread discussing pitman arms; http://www.mtfca.com/discus/messages/29/27096.html.
Here are some photos of the small bracket (black) and large bracket (grey).
The grease nipple in the small bracket is not stock.
To my knowledge there may be two other brackets: a large one for the Torpedo which has a lower angle and and a bracket for the TT truck that has a steeper angle. I believe the TT bracket looks similar to the small one. Someone else may wish to comment.
If you post pictures and dimensions we can tell what you have. You can use all the suspension components from any given year and they work fine in any year Model T in most cases.
Are you able to look (for example) at your tie rod? Look at the ball. Is it integral to the tie rod? Or is it a separate part?
All the information you need to determine what you have is located in the posts above. Get out a crayon, a piece of construction paper and a yardstick. Make a list.
If you need different parts to fix the problem they are cheap and easy to find. Not sure what part of the country you are in but there are used T part dealers all over.
OK, I've done some checking on my '12 Touring and comparing to the photos posted.
My steering bracket is clearly the large type, as it should be. But the tie rod has the separate ball, making it a 1920 or later type. I still need to figure out how to measure the pittman arm length to see which one I have. I may have missed it in this thread, but which pittman arm should go with an early car, the 3.60 or the 4.25 ?
Also, where are the drag link measurements taken ? Center to center on the ball sockets ?
I did check to see whether the pittman arm goes over center in either direction and the answer is, no, it definitely doesn't.
Measurements are center to center.
A 1912 drag link is easy to spot. It is adjustable at one end, and the adjuster threads are coarse.
This is a picture od a 1910 drag link. The '12 - 13 style is the same except the rod has coarse threads.
Royce: When you took those pictures, you should have removed the end caps and bolts, to give us a more accurate comparison.
I've taken a more thorough look at the steering system in my '12 Touring. Here's what I found:
Steering bracket is large type per Robb's post.
Drag link is 30.60" long, center to center. Adjuster on passenger side. Coarse threads.
Pittman arm is 4.25" type as depicted in Chris' post.
Tie rod is detachable ball type and is 47.69" center to center.
Where do I go from here ?
From your description you only need the correct tie rod, unless I am missing something. Try calling Chaffins, or perhaps head down to the Long Beach swap meet, not sure which is closer to you.
What a great thread to stumble upon. I bought a 5:1 conversion kit from Texas T's years ago and have issue with it turning fully one way and not the other. If I remember correctly it goes fully right, not left. I have the correct year drag link for the car but maybe not for the new ratio. I had asked our local used parts guy at the time if a longer link was available but not sure if I got the correct response. I had attributed it at the time to the key way on the shaft being machined in the incorrect place. Bah! Looks like I'll be tearing this apart tonight. Been some years since I put it together.
Just checked it out and looks as though I had solved the problem already. Thinking back it may have been the pinion gear placement itself. The one goofy thing I've noticed though is with the wheels in the air, when I turn the steering wheel to its lock, I can push the front wheel over a bit farther and the steering wheel will continue to move. I assume this is normal but kind of baffled as to what is going on there. All new bushings and pins, bottom ends of tie rod sockets were welded up and socket restored, very minute amount of slop in steering system. Anyone with any thoughts on this?
Does your steering box have a groove in the bottom of it and one pin longer than the other two, on which long pin moves in the groove? This improvement was made to keep the steering from going over center. If you have that kind of steering box, perhaps the groove on one side is worn and although you come to the end of the groove while turning the steering wheel, moving the wheel itself forces it to move. If that be the case, your fix would be to fill the groove in the steering box and re-grind, or replace the steering box.
Another possible cause and also an indicator that you have or don't have the correct drag link would be: when you have the wheels pointing straight ahead, the pitman arm should be vertical. If it is on an angle to the left side of the car, your drag link is too long. If it points toward the right side of the vehicle, the drag link is too short.
Norman, yes it does have the groove in the bottom, it took me some time to find on good enough to re plate.
Seems I was getting a false positive of sorts, I worked it back and forth to look over once again and noted the pitman arm was a few degrees to the right but after checking the travel again decided to myself it was equal. Funny how the voice in your head gnaws at you... I couldn't help but think there was more going on here. I watched the steering bracket a bit more closely and grabbed my 9/16" wrench. Ha, my memory had been correct and no I hadn't found the problem but it decided to find a happy medium for me. Once the steering box was pulled tight against the frame the pitman is much more out of plumb. As noted before, turns to the right farther than it does left. No one mentioned the steering bracket not being tight. Being tight should go without saying I guess. The car is in assembly stage right now so stuff that comes off often, have no cotters. Now I get to look for a longer drag link. This is what happens when you walk away from a problem and not handle it while it is facing you. Had this lesson before, laugh if you want, I laugh at myself all the time.