View Full Version : Steering Steering knuckle arm interchange?

06-04-2014, 10:11 AM
I have managed to get the Tribaker (http://tribaker.wordpress.com) running and street legal now, and wonder if there is a way to get it to turn sharper. It has a modified 41' Commander planar front end and an Omni rack and pinion to steer. The steering knuckle arms are really long, and I wonder if later arms are shorter, or even interchangeable. If necessary, I'll get some arms and shorten them some with the TIG if I have to, so which arms of any length are bolt on?
I'm thinking that they need to be about the length that they are on an Omni.....?

06-04-2014, 12:50 PM
Congrats on getting the Tribaker up and running. It's definitely a one-of-one and will be popular at shows.

But as to your question; the rack and pinion conversion reality strikes again. Few-to-none of the production racks have enough travel to work with the stock box steering arms, so yes, your arms need to be about the same length as the donor car.

When I did an R&P on my '56 Hawk, I removed the stock arms and machined the taper further back and the end re-threaded. Kids, don't try this at home. Several have asked me to duplicate the arms and there's not enough money to even tempt that again.

I mention this since fabrication obviously is a challenge you relish. I don't know what '41 planar arms look like, but could they be shortened by the method I used?

jack vines

06-04-2014, 03:19 PM
Jack, I think the arms are too scrawny to do it as you did. I'm thinking more like cutting thru the arms in a "V" shape twice and beveling the edges to give a longer weld with better penetration.

knuckle end IZZZZHHHHH< <HHHH< <HHHHHHO tie rod end

Mike Van Veghten
06-04-2014, 03:35 PM
Those arms are really long. Was looking at the front of a 41 coupe closely this past weekend. Interesting for sure.

Rather thAn cutting them using the "V" method I'd try the lath method.
While it would be a little more difficult, make a plug and socket style joint, with the plug dimater fairly large in diameter, maybe 1" lg. This would provide additional stability thAn just the weld only. Make the fit a light interference fit, then weld with two plug welds and the weld around the visable joint.


06-06-2014, 09:57 AM
I found some NOS knuckle arms in my Stude junk box which are from a 39-40 Champion which have the same 5/8x18 thread/nut on the spindle end. They are straighter and 1.625" shorter. The Ackerman is different, but the Champion wheelbase is closer to the Tribaker, so they may actually be a very good option if it turns out that the taper is the same. I think it probably is, since they fit perfectly in the 49-50 NOS knuckle that I have....