Hey guys, so I have a 56 f100 box I want to use for cowl steering, seems to be a common sort of thing to do, just wondering how people have lengthened the output shaft for the pitman arm to bolt to, so it extends out through the cowl? Or do you just build a pitman arm to suit? Sent from my iPhone using Tapatalk
This is commonly done. It is imperative that the weld design and execution be of professional quality, and the shaft be absolutely straight. Same applies to the shaft enclosure tube, and there should be an appropriate bearing and seal at the outer end. There are lots of threads you can "google" on the HAMB that discuss this. There are also many instructional resources on the internet. One shop I stumbled across on the net was Jokerr Fabrication in Brownsburg, Indiana, and some pics of his procedure are here: https://www.google.com/search?bih=2...EHYVpDV4QgIoDKAJ6BAgKEAc#imgrc=LIcnmDhl70vdMM
Yeah I’ve seen how he does it, just seeing what else is out there, like what else has been done, I’m half tempted to machine a whole new sector shaft up from blank Sent from my iPhone using Tapatalk
I believe Hilton Hot Rod Guys use a converted F100 box manufactured by a shop that's in I think Tenn? He has had a for sale ad on here from time to time.
As hard as a good 53-56 box is to get these days I'd be looking at something a little less money myself. Surprised the 65-66 Truck box hasn't been used. Starts out with a much longer sector shaft, no more difficult to mount and already has a splined input shaft. Can you see this turned 90 degrees?
Isn't the sector gear integral with the shaft? You have access to machinery that can cut that gear? I ***ume you don't have a forge, so would need to start with a pretty large steel billet. Is there any box available that has a pitman shaft of the length you need? If close, you could make up the difference with a small extension on the pitman arm hub, or even a long extension if you add an outboard support bearing. Later Ford pickups, and Chevies, had a fairly long shaft, but I don't know which way they rotated. I found a perfect box at a swap meet once that I think was from a fork lift; don't know what the source was. I was thinking of making a cowl steering set-up using a u-joint at the box. I'd make a splined flanged hub that would go on the box; could cut a sleeve with splines out of the original pitman arm to use as part of the hub. The u-joint would attach to the hub, then a shaft of the length needed. The outer end of the shaft would have a support bearing, and a flange to which the pitman arm is connected. Or the pitman arm could be integral with the shaft. A possible candidate for the u-joint: there is a flexible couping made for industrial drive equipment that consists of several stacked SS discs. (Think of a circular gasket shape, 5" OD x 3.5" id, .005" thick [dimensions are not actual, just to help you envision it], with 6 evenly spaced 1/4" bolt holes. Each set of three alternate bolts would attach to three-armed hubs on either side. You can eliminate the u-joint if you can fabricate/machine parts that are perfectly straight. Make a tubular pitman shaft. One end would have an internal splined sleeve (machined out of a pitman arm). It would connect to the steering box output shaft with a bolt (maybe Allen head) and thick washer inserted down the pitman shaft tube. The outer end would have a bearing adjacent to the pitman arm. All this would be inside a larger stationary tube, that connects to the box with an appropriate flange, and supports the bearing on the outboard end.
I saw a brand new long-pitman-shaft steering box at a swap meet that looked perfect. I was playing with it to see which way it rotated, and the vendor told me "I read an article on how to build a center steering set/-up using this particular box. So I bought one. Come to find out, it turns the wrong way." If this were for a single-seat Indy type replica, some think that you can just flip the box over and put the pitman arm on the right side. (Most Indy cars were that way, but for an entirely different reason.) If you go through the mental gymnastics to contemplate this, you'll see that it would still backwards! Maybe someone in the world makes a compact little in-line gearbox that reverses rotation, perhaps with planetary gears or like a differential with the spider gear body locked in place. This could be used on the steering box input shaft, where the torque load is a small fraction of the output side.
The Pete Eastwood thread on cowl steering is an eye opener. https://www.jalopyjournal.com/forum/threads/cowl-steering-just-stop.1101046/
Figured out the shop making the F100 boxes for cowl steering. I missed it by a few states. It's Mikes Speed Shop in Kannapolis N.C. He runs an ad on here from time to time. I'd do a search as he runs pictures sometimes? Found his handle on here, it's mikesspeedshop.nc
Schroeder steering sector shafts turn 360 deg. and the pitman arm splines are fully splined so they can be flipped over and the pitman arm turned 180 deg. and it will operate correctly.
The JoKerr method is a good solution. I took a different approach, making a sleeved pitman shaft extension and shortening the steering wheel shaft with a sleeve insert to permit the p***-thru of the horn wire. I'll just post pics rather than write a long-winded explanation. The only drawback to this method is it is a one shot deal. The box couldn't be dis***embled without cutting off the extension.
If you have any amount of suspension travel you will have bump steer with cowl steering. That is a fact.
A modified p***enger car steering for center steering is a very poor choice, especially for competetion use. The farther you go from center where there is essentially no play, to lock, the more play you get. It will work on the street because you are running in the center most of the time. On a dirt car, you are at far lock to the right much of the time where there is the most play and the front end will go wherever it wants. I drove several dirt sprint cars with modified p***enger car steering and it was not good. A better choice would be a midget or sprint car steering. They come in both manual and power types. If you do research on where to buy these you will find they are cheaper in the end if you figure the cost to modify a p***enger car unit. There are numerous ways to design a front end to go with center steering so it does not bump steer. If you have never driven a street roadster with POWER center steering, you haven't lived.
The Jalopy Journal
