MTFCA Forum

My son has a 1911 touring, a nice older restoration that runs well. It does have a small problem with the steering. Sometimes when you are making a fairly sharp turn at low speed, it can suddenly want to turn more sharply. It's not going over centre, the steering wheel does not turn the wheels the wrong way. The kingpins, tie rod ends and wheel bearings are in good condition, not sloppy, and it steers very well going down the road. I can't imagine this would be a factor, but being an early '11, it has one piece spindles. Has anyone else had this problem, and if so, what did you do to solve it?
Thanks for your help. John

John, does it happen turning in both directions? When the steering is centered, where is the steering arm on the end of the steering column pointed?

Check tie rod and drag link length versus the tables in these older posts?

http://www.mtfca.com/discus/messages/17 ... 1317650782

http://www.mtfca.com/discus/messages/25 ... 1347321800

Have you measured the castor, camber, and toe in? An alignment problem can cause it to pull. A common problem with the early T's with the wishbone bolted above the axle is caused when you hit a curb or pothole hard. Even if you have not hit it hard in over 100 years, someone could have done so. This will bend the spring hangers causing the change in castor to what is called negative castor. Think of the castors on a chair. The axle is always behind the wheel as you push the chair. If you happen to push in the direction of the axle, the castor will spin around. Same thing happens to the car wheels. The top of the axle should be tilted toward the back of the car and the bottom toward the front. If it is bent, it will have negative castor. The camber and tow in are mainly used to keep the wheels going straight ahead when you are not turning.
In the Ford Service manual paragraph 147 page 45 the castor is called Pitch. To measure this park on a level floor, preferably a concrete slab. Place a square with one leg on the floor and the other against the axle right against the spindle body. From the front of the car measure the distance between the spindle body at the top and at the bottom. The difference should be no less than 1/4" nor no more than 5/16" The top should be leaning toward the back of the car. If it is not within these measurements, it must be bent to fit. I have not personally had to do this, however, you would need a tool similar to a large pipe wrench with a very long handle, perhaps, with a piece of pipe on the handle and use as a lever to bend to fit.
You can purchase from the parts suppliers, a brace which bolts below the axle and is fastened in the back of the radius rods which will keep the front axle more stable. This is not a stock piece of equipment, but a good safety device.
Norm

John,

Welcome to the forum! It looks like this is your second posting.

Even when the Model T is set up properly the cars running the 30 x 3 or 30 x 3 1/2 inch clinchers have a very quick steering compared to modern cars (1928 and later Fords etc.)

And from Jem Bowkett's 2009 posting he states his late 1909 had a similar issue -- it would go past a point and would NOT self-center anymore but go full lock in that direction. It did NOT go over center -- but it did go full lock:

++++++++++++++++++ From the old Forum ++++++++++++
located at: http://www.mtfca.com/discus/messages/80 ... 1238532286

By Jem Bowkett on Monday, March 30, 2009 - 11:53 am:
My 09 has cut-outs on the back of the axle which allow the steering arms to go very near to parallel to the axle. If you swing the wheel too far over, it goes beyond the point where self-centring operates and pulls the wheel round to full lock, but it is not actually 'over-centre' on the pitman arm - you can yank it back, but I've only experienced it at walking pace. This applies equally on both locks.

It is however scary, and it worries me that it could occur when hitting a pothole at speed and tip us up. I have been thinking of putting some sort of stop - look at a Model A (the modern one, not the 1903) and the nut that holds the stubaxle pivot pin in place is a special long one which is a steering arm stop, so even if you lose the draglink, it will never go beyond normal lock.

And he has additional comments at: http://www.mtfca.com/discus/messages/80257/86608.html

And Jem also commented later that same year at: http://www.mtfca.com/discus/messages/80257/114164.html

By Jem Bowkett on Thursday, November 12, 2009 - 12:29 pm:
... When you get near to full lock, the pressure against the wheel at that acute angle pushes the axle back (top mount wishbone of course) so the castor becomes negative and it wrenches round onto full lock. Takes a really hard pull to get it central again.

++++++++++++++++++ end paste from the old forum +++++++++++++


There are several things that could be contributing to that issue. Some of those you have already said are in good condition (the kingpins, tie rod ends and wheel bearings are in good condition, not sloppy). But you also should still check:

With the car stopped and the front wheels on the ground, turn the steering wheel. It is also good to have someone turning the wheel while a second person looks for lost movement (i.e. a drag link, a pitman arm etc. doesn't move unitl the steering wheel is turned a couple of inches.) How much movement in the steering wheel before the wheels start to turn? You don't have to turn the road wheels -- you just want to find out how much play is at the steering wheel. And since you said the problem was when the wheels are in t a tight turn -- check it again with the steering wheel turned close to full lock. How much back and forth movement in the steering wheel before the front wheels start to turn? Is it more than when the front wheels were pointed straight ahead? But I would recommend you have someone hold the front wheels still and have someone else turn the steering wheel to see how much slack / slop there is.


the drag link -- does it have slop

the pitman arm (is it lose on the shaft - i.e. does the shaft turn a little bit inside of the pitman arm casting?

Is the lower steering column bracket firmly attached?

are the 4 rivets holding the steering gear case together (1909-very early 1915 steering case -- the later steering case is a one piece) at the top of the steering column still rivetted tight (no movement)

is the steering gear case at the top of the steering column still rivetted tight to the column (2 rivets)

Is the steering column base at the firewall tight and the firewall supporting it properly

Is the front axle held properly in place (it should move up and down freely with the spring supporting the movement but not much side to side or forward or backwards.)

Are the U-bolts connecting the front spring to the front cross member holding the spring firmly to the front cross member

Are the spring shackles and bushings in good shape -- allowing free movement of the spint up and down but not lose. Note worn bushings in the spring perch or in the front spring can cause it to be lose.

Are the front axle spring perches firmly attached and on the correct side of the axle (they can be installed on the wrong side easily with the later below the axle spring perches (1919ish to 1927). And there have been cases with those later spring perches where one side was correctly installed but the other side was the same spring perch but installed on the wrong side of the axle. For the 1909-1919ish above the axle spring perches -- if the wishbone and the spring perches are both in good condition you cannot install the wishbone if the perches are on the wrong side. That is because the hole for the wishbone is larger at the back side and smaller at the front where the threaded portion enters. But if they are worn badly -- Yes even the above the axle spring perches can be installed wrong and the wishbone fitted.

++++++++++++++++++ another 2009 posting ++++++++++++++
[Ref: http://www.mtfca.com/discus/messages/80257/114164.html
By Erik Johnson on Thursday, November 12, 2009 - 02:27 pm:
The early style front perches or spring hangers (wishbone over axle) are designed to accept the wishbone prongs from only one direction. (The wishbone holes on the perches are slightly tapered and are flat on the front and countersunk at the rear to accept the wishbone prongs. Likewise, the wishbone prongs are slightly tapered.)

If you are able to insert the wishbone into the perch from the opposite (incorrect) direction, then the wishbone prongs and/or the holes in the perches are severely worn.

Erik Johnson
+++++++++++++++++end old posting ++++++++++++++++

Is the wishbone holding the axle firmly with approximately 5 1/2 degrees of positive caster? (That was explained in more detail by Norman above -- Thanks Norman). Originally a 1909 to 1919ish would have the above the axle wishbone but sometimes they are replaced with a below the axle wishbone and/or braces below the axle are added to the above the axle wishbone.

Is the ball on the end of the wishbone that fits into the engine pan have minimal play but still free for the wishbone to move as the front spring absorbs bumps etc.

How to check the front axle caster to make sure it is not set too low. More positive caster makes the car's steering more stable going forward but more unstable backing up. Never back up fast in a stock T as by design the wheels tend to go full left or right when backing up. That is because "IF" you have the correct 5 1/2 degrees positive caster on the front axle -- when you are going backwards it has the effect of being 5 1/2 degrees negative and the front wheels want to go hard left or right. In the USA we have shopping cars that have casters on the front. And if I move the cart reward, the front wheels on the cart will turn around. The posting at: http://www.mtfca.com/discus/messages/29/40382.html shows the paragraph Norman referenced. It also has how to use a plumb bob and pencil to do the check instead of a square.

From the MTFCA safety check list located at:

Steering
• Steering wheel has minimal (less than 2”)
to no play ____

• Acceptable wear and minimal to no play in:

 Radius rod (wish bone) to crankcase ____
 Ball arm (pitman arm) to steering
gear connecting rod (drag link) ____

 Steering gear connecting rod
(drag link) to yoke ball ____

 Spindle bolts (king pins) ____

 Spindle connecting rod (tie rod) bolts ____

• Cotter key (or lock washers, if holes not drilled)
installed in the following:

 Radius rod (wish bone) to
front axle perch (2 required) ____

 Steering gear bracket to frame
(3 required) ____

 Ball arm (pitman arm to steering
post (1 required) ____

 Steering gear connecting rod
(drag link) to yoke ball (2 required)

Steering gear connecting rod (drag link)
to steering gear ball (2 required) ____

• Spindle connecting rod (tie rod) to
spindles [2 (1 per spindle)] ____

• Spindle bolts (king pins) [2(1/spindle)] ____

• Spindle arms [2(1/spindle)] ____

• Front spring hangers (shackles)
[4 (2 per side)] ____

• Front spring to frame [2 or 4 required,
depending on year] ____

• Yoke ball (1 required) ____

• Safety-wire crankcase studs holding
radius rod ball cap ____ NOTE -- cotter keys will keep the nuts from backing off but the studs can back out with the nuts -- that is why it says "Safety-wire"

• Grease in steering gear case and steering
gear bracket (also check gear post and
pinion gears for wear) ____

• Check for play in steering gear
case to steering column
(check rivets/taper pins) ____

• Lock screw installed in quadrant

Respectfully submitted,

Hap l9l5 cut off

Be very suspicious of your wishbone if it's the "over the axle style". What you describe is not a "small" problem.

From a recent posting of mine....

I test drove my friend's 1914 just after he bought it. Seemed fine until I made a left hand turn. Both front wheels swung hard to the left, nearly causing me to hit a stopped car. If I hadn't been on my guard to begin with, it would have been a collision. When we got back to my friend's house, I looked over the front end. All looked fine. Then I turned the wheels left again, with the car standing still, and saw the whole front axle roll forward. It actually was as if it were wanting to roll under the car. It caused the caster angle to go from normal to maybe 15 degrees the wrong way, (i.e. forward).

Turned out, the studs at the ends of the wishbone, along with the holes in the perches, were completely worn out and sloppy loose. The axle didn't just move by the amount of the excess clearance however. The arms of the wishbone actually rotated torsionally as the axle rolled forward. Hard to describe, but freaky to watch and scary to drive! So yes, it was largely a matter of totally worn out parts, but it also demonstrated the dynamics of what occurs when the wishbone fails. I don't believe that they just bend or break, (though I'm sure that some do). I believe that even a wishbone in good condition can rotate in the perches and twist, allowing the axle to "go under", when an out-of-the-ordinary force is applied. It was a convincing demonstration. That car now has an excellent wishbone, nos perches, and an under-axle brace.

As Hap has quoted me at length (Cripes! am I now a grey-haired T guru?) I'll put in my two-pennyworth.

Sounds very like the problem I described, but it really only happens at parking speed, because it is right at the limit of applying lock. You need to look at all the other suggestions if it happens at any reasonable pace and moderate lock. But it doesn't sound like the horrific mess that Jerry was faced with.

The late Ralph Ricks and I both thought the dangers of the top-mount wishbone were exaggerated and felt the blame for some accidents was due to the T's very quick steering ratio. Ralph fitted a 1937 steering box on his Great Race car. Try this: jack up the front axle, hold the steering wheel while an assistant pushes against a front wheel - you won't be able to stop the wheel being pulled from your hands. That's what happens when you hit a pothole. Look at this sketch: point B is the normal tyre contact and the difference between that and point A gives positive castor. Go into the pothole and point D becomes the tyre contact - sudden massive negative castor and wheel can be torn from your grip. That said, I have survived 40 years driving the car. But I fitted one of these some years ago: it does what it says on the box. Jack up my front end and you cannot move the road wheel by hand, you have to use the steering wheel. Potholes are not so scary now.

Wow. Lots of thoughtful input here. At the moment, the car is in cold storage in my garage, but after Christmas I'll move it Into the heated workshop and follow up on the suggestions. I'll let you know how it turns out.

Thanks

John

Jerry's description of a worn wishbone and perches allowing front axle fold-under certainly rings a bell with me. I have experienced the same runaway steering with an under-axle wishbone when a lost perch nut allowed the front of the wishbone to go loose. It put me in the ditch, destroyed a wheel, and crunched a fender and splash apron. I now pay particular attention to those nuts and cotters.