1912 Buick Question

[ROD W]

When they say 56" Tread,  is this centre to centre of the tires or outside to outside

[Leif Holmberg]

Thread-56 must be center to center of the tires.That`s the way to meassure the thread.

Leif in Sweden.

[ROD W]

Thanks Leif. Thats what I was thinking,  but wanted to make sure.

[Daves1940Buick56S]

What do they mean by semi-irreversible steering?

[trimacar]

1 hour ago, Daves1940Buick56S said:

What do they mean by semi-irreversible steering?

Man, I love a good question that's semi-unanswerable....or is that semi-answerable?

 

The term "semi-irreversible" is, to me, nonsense.  Possibly some automotive engineer will chime in and explain, but to me, either a steering is reversible, or non-reversible. 

 

And, by that, my take of the meaning is that with a reversible steering, you can manually push the front wheels one way or the other, and the steering wheel will turn appropriately.  Non-reversible means that you can't turn the steering wheel at all by trying to move the tires.  Thus, a non-reversible (or irreversible) steering doesn't transmit the road shocks back to the steering wheel.

 

Semi-irreversible would seem to indicate an in-between condition, sort of like being semi-pregnant.  Don't think either can happen......

[Daves1940Buick56S]

1 hour ago, trimacar said:

And, by that, my take of the meaning is that with a reversible steering, you can manually push the front wheels one way or the other, and the steering wheel will turn appropriately.  Non-reversible means that you can't turn the steering wheel at all by trying to move the tires.  Thus, a non-reversible (or irreversible) steering doesn't transmit the road shocks back to the steering wheel.

 

Semi-irreversible would seem to indicate an in-between condition, sort of like being semi-pregnant.  Don't think either can happen......

OK, interesting. Looking at the picture of the car, I can see that the pitman arm of the steering box is mated with a larger shaft on the end of what I suppose is the drag link. I wonder if Buick used springs here like in the drag link connector of my 1940. If so, I guess you could say it was semi-irreversible since there would be some movement of the wheels before the steering wheel would move. I agree from an engineering standpoint, reversability is binary. But you gotta love marketing!

 

Cheers, Dave

[trimacar]

Yes, there were springs in that larger end, and the ball of the pitman arm rides in it, this takes some of the road shock out of the system.  My 1910 Model 16 Buick has this feature.  The literature also discusses the semi-irreversible point, interesting....

 

The Buick literature doesn't tell you what kind of steering box, but it's a Jacox (Jackson Church Wilcox Company) worm and split nut style.  A central worm on the steering shaft guides two split nuts, which then move the pitman arm.  The interesting feature of this type of steering box is that it's possible to put it together incorrectly, with the large split nuts either upside down or on wrong sides, don't remember which,  and your car will steer the opposite direction from the way you turn the steering wheel!  Talk about messing with somebody big time......

 

If you're fascinated by this Jacox steering, here's a good description of it, along with parts laid out for your inspection and pleasure:  http://www.vsccsa.org.au/restoration-topics/jacox-steering.htm

Edited April 28, 2016 by trimacar (see edit history)

[FLYER15015]

Darn,

I thought semi-irreversible meant that you could move the steering wheel over to the correct (left) side of the car, but it would be very difficult, and irreversible meant that if you did, you could never move it back.

 

So glad the post and picture from "trimacar" straightened me out !

 

Mike in snowy Colorado

[alextheantiqueautoguy]

On 4/28/2016 at 2:08 PM, trimacar said:

Yes, there were springs in that larger end, and the ball of the pitman arm rides in it, this takes some of the road shock out of the system.  My 1910 Model 16 Buick has this feature.  The literature also discusses the semi-irreversible point, interesting....

 

The Buick literature doesn't tell you what kind of steering box, but it's a Jacox (Jackson Church Wilcox Company) worm and split nut style.  A central worm on the steering shaft guides two split nuts, which then move the pitman arm.  The interesting feature of this type of steering box is that it's possible to put it together incorrectly, with the large split nuts either upside down or on wrong sides, don't remember which,  and your car will steer the opposite direction from the way you turn the steering wheel!  Talk about messing with somebody big time......

 

If you're fascinated by this Jacox steering, here's a good description of it, along with parts laid out for your inspection and pleasure:  http://www.vsccsa.org.au/restoration-topics/jacox-steering.htm

 

That's what I call an answer! Attaching the picture is perfect.

[trimacar]

It's all so confusing, I'd take down the post, but I think the post itself is semi-irreversible......

 

[Mark Kikta]

Just a couple of other pictures showing what Trimacar was mentioning about the pitman arm.  Here are a couple photos of my 22 pitman arm at the drag link and a photo after I took them apart and cleaned them.

[Oldtech]

Well... If you interchange those blocks in the box it goes right when you turn left. 😁