I have an un-restored 1913 Touring that does not handle well on the road. When driving and cruising down the road, I have to keep a tight grip on the steering wheel because the car tends to be "over-responsive" to any steering I implement. For instance, when driving down the road at 25 mph, if I make a steering correction to keep the car centered in the lane, it feels as though the car wants to keep turning more, even after I stop the correction at the steering wheel. This is also the case on a bumpy gravel road where the body twists and flexes. Meaning that when the body twists, I can feel the car "dart" in one direction or the other during the flexing. It has good spindle bolts and all front-end hardware is tight with no play that I can find. I also pulled the steering shaft and replaced the bushing down by the pitman arm. Any help would be appreciated.
The front axle kingpin angle is reversed.
The axle must slant so that the angle of the kingpins is such that the bottom of the kingpins is forward of the top. This makes the car tend to "caster" in a straight line.
Very likely the left and right spring perches are reversed, or the wishbone is bent.
Here's a picture that might help, showing the tilt that is manufactured into the perches:
Ditto what Royce said and a few additional threads on the subject, since I already looked them up:
Several things could cause that problem.
1. The most common cause will be that the axle does not have proper 5 1/2 degrees of caster (Ford Service bulletin below will call that “pitch” that Ford recommended.
2. What is caster – the same principle of the front fork on your bicycle? In the case of a Model T the lower portion of the king pin should be slightly ahead of the top portion of the king pin.
3. How do you check to see if it does or does not have the correct caster? See below and also the excellent thread at: What's wrong with this picture?
4. Why would it be out of tolerance? The previous owner (or perhaps you if you removed and replaced the spring perches and/or if you removed the axle – left the spring perches in place and turned the axle around. Also if the axle and/or wishbone was bent and/or altered. See: Previous Owner installed the spring Perches backwards at: http://www.mtfca.com/discus/messages/411944/423637.html?1392249973
5. Your early car would have had the spring perches with the wishbone above the axle. They do not have the machine marking but they do give the same 5 1/2 degrees of caster.
Good luck and let us know what you find out.
Hap l9l5 cut off
"The axle must slant so that the angle of the kingpins is such that the bottom of the kingpins is forward of the top."
"...The front axle should have a 5 1/2 degree pitch toward rear of car..."
OK, it is early - I need more coffee to comprehend...
Royce and Hap,
Thanks for the quick replies. However, the king pin angle is correct - or at least looks correct. (Sorry I didn't mention that in the original thread) I have not measured the angles, but the tops where the oilers are has a definite slant toward the rear of the car. It's not quite as much as on my 15 (which handles great) but the rake is definitely there.
By the way, I will perform the check outlined in the ford information above when I get home this evening!
If the toe in is actually toe out it can cause the same problem. The toe in needs to be set at 1/4" less at the front.
I'll check that too....
James...you might want to double check your pitman arm...I went through the same thing on my '15 last month and after checking, and re-checking all the steering gear, discovered a very slight movement on the pitman where it is keyed onto the shaft. Took it off, double-checked the key, the slot, etc. needed a new key. Also made sure it was as far up on the shaft as tight as can be prior to putting on nut. Cured the problem.
Similarly, I still have the same problem on my '20 because the steering case in the quadrant is not tight, and even though I shimmed it and made it better, it still has enough slop to cause the same issue...some un-even-ness in the pavement can cause the wheels to move a bit from the slop even though my hand's tight on the wheel. Check for that also. Just a thought. I'm learning every day!
Will do Tim... Thank you!
"...if I make a steering correction to keep the car centered in the lane, it feels as though the car wants to keep turning more, even after I stop the correction at the steering wheel."
I've had similar experiences with two T's. And those were on cars with NEW repro Pitman arms. In both cases the keyway was too wide, allowing the arm to shift on the steering shaft. I found good original Pitman arms, end of problem(s).
Jim, if you take a good look at your pitman arm, it may just have a DB on it. Hope you find your problem, and while you are at it, check for tightness on all of your ball caps.
I could be wrong, but I believe that the early wishbone cars had a 4-1/2 degree caster, and that it didn't become 5-1/2 until the new wishbone appeared in '19.
I had the same issue as James with my '14. Turned out that the passenger axle yoke was bent upwards 1/4", reducing the camber on that side. That and not quite enough toe-in made it a squirrely ride.
I could be wrong but I recall that the early wishbone gave the cars a 4-1/2 degree caster, not becoming 5-1/2 degrees until the new wishbone came out in '19.
I had the same issue as James on my '14. Turned out that the passenger side axle yoke was bent upwards 1/4", reducing the camber on that side. That and not quite enough toe-in made it a very squirrely ride and decidedly less of a joy to wrangle around the roads. What a difference now that those issues have been corrected.
Dunno why the double post happened. Stupid 'puter.
When logic and standard reduction thought fails you...look to the abstract...
Wood felloe non-demountable wheel? All else seams fine? Front end still feels 'light'? Think you felt a mild shimmy but you stopped the car before it got severe? Then it would not reappear on command no matter what you tried to do?
Look for a loose fellow rivet (or rivets), or, a rivet missing a head inside the wheel rim and the rivet stem held by friction only...
BTDT! Took me close to a year to find it on the '15 after going through the same as you are experiencing now!
Changed to a spare wheel with tight felloe and good rivets ...that Roadster now does 45+ without a hiccup or a fear from me as to moving on down the road and the state highway!
My friend's '14 had a similar problem. While the car was sitting still, the kingpin angle looked correct. However, he had the original "high" style wishbone, with no accessory lower support brace. It turned out that when you steered the car to the extreme right or left, the axle would sort of turn under and the caster angle would completely reverse, making the kingpins now slant forward at their tops. When we looked closer, the wishbone ends and the holes on the perches were heavily worn. This allowed lots of movement between the axle and wishbone and an otherwise good caster angle would change dramatically.
Better perches and wishbone were installed, as well as a lower brace.
All.. Thanks for all the information. It's been extremely helpful. I decided to perform the Square test shown in the old document supplied above by Hap. Attached are three pictures. One is of my 1913 which is in question and it shows 3/8" of caster angle. Also shown are pictures of my 1915 Touring and 1925 Coupe - both cars of which handle like a dream and are very "tight" feeling with regards to steering feel. By "tight" I mean that the cars respond only to the movements I input to the vehicle.
As can be seen, the 1913 touring has FAR less caster than the other two vehicles. However, it is still outside the ford specs showing more caster than required.
I am now going to check all the other items that have been suggested by members in this thread.
Larry - The Pitman arm is a Dodge Bro's unit and is clearly marked.
I will mention that I have one of those old ANCO spring loaded ball caps on the passenger side of the drag link. I'm suspicious of the spring. I'm also going to check the pitman arm key and the roll-over while turning.
Feedback on the pictures is welcome. If nothing is found, I will say that I'm going to bend the perches to equal the bigger angle shown in the photo of my 1915 Touring. That thing handles like a NASCAR ride.... Thanks again to all.
Although your 1915 handles like a dream, It's got to be really squirrelly backing up!
The castor on your '15 and '23 is too much.
On your '13, start at the steering wheel and take up every bit of "play" all the way from the gears in the steering quadrant, (Maybe turn the gears over or replace them to get a more snug fit)all the way to the drag link bushings and ball. Then check your wheel bearings, too!
: ^ )
Ball caps were adjusted, the steering bracket has had the bushing replaced. I will certainly check the gears but it all feels tight. One thing I did notice tonight is that when I turn the steering wheel back and forth, I can see the bracket flex back and forth where it bolts to the frame. ITs as thought the frame is flexing right there. I looked for a crack but didn't see anything wrong. The wood blocks are there but they are old and original. Backing up my 15 is a piece of cake. Backing up my 25 can be squirrely if I back up too fast while turning.
Better check the toe in. The caster appears to be perfect.
As for the Apco spring loaded cap, the spring should be adjusted so that it is bottomed out.
I'll check Royce.... Thanks.
I would not drive a T with unsupported over the axle wishbone. It can flex at any time.
1. Years ago I had a 26 two door sedan that had a terrible shimmy. I went through the steering several times and could not find the problem. I used to have the wife sit behind the steering wheel and jerk the wheel back and forth. That usually finds any problems quick but that time I could not find it. Finally the last time I Had her jerking the steering wheel one last time. I finally saw the problem. I had forgot to TIGHTEN UP THE BOLTS ON THE LOWER STEERING COLUMN BRACKET TO FRAME ! After that no shimmy
2. Another problem can be ALL steering shafts have a knob between the lower bushing and the pitman arm. This is caused by wear from years of wear from the bushings. You must put your shaft in a lathe and machine the shaft to the same size as the worn spot or when you ream your bushing so the shaft can go through the bushing the Bushing will be to LARGE for the worn spot in the shaft.
I have never miked a shaft yet that did not have the knob just above the pitman arm. Normally you do not need to mike the shaft just run you fingers down the shaft and you can feel the KNOB.
Make sure that your king pin bushings are getting lubed, especially the lower bushing may not be getting sufficient oil. Also make sure the tie rod pins are free and lubed. The condition you describe can be caused by too little or negative caster as others have said, and also from binding or stiff steering. When you turn the steering wheel a little, the wheels stay that way and then you must turn them back a little. They should self center, and positive caster helps do this but the pins must be free.