By John Niolon
A tilt column is one of the nice additions you can make to a vintage truck, especially if it's connected to power steering and independent suspension. While there are several different types of columns in use in the Mid-50's trucks, one of the easier swaps is the Mid-60's G.M. column. They are the right lengths. They require very few alterations; they are readily available and affordable.
I read all the articles I could find and made my trip to the salvage yard. An '86 Caddy Sedan De'Ville gave up it's column. It was a very clean tilt/slide unit that showed little wear and no slop in the shifter or the lock mechanism. Be sure to get as much of the wiring as you can (including the connectors) and the saddle mount and copper bolts from under the dash of the donor car.
The first thing that was necessary was removing the floor plate from the column. This seal/mount is tack welded to the column and of course is at the wrong angle for the truck floorboard. It would probably be possible to cut it loose and reattach it at the proper angle with some bending and hammering. But, since I wanted to secure the column differently at the floor level, I removed mine and planned on something a little different.
Measurements and calculations
Once you have a clean column, the next step is deciding where it will enter/exit the floorboard. I had replaced the floorboards and lower firewall panels in my truck so I had a clean slate to use. If your floorboard is original and has the large opening already cut, you can probably fit it in this hole with no problem. Many of the older trucks had a steering column angle that was too steep for comfortable cruising. Experiment a little with your column angle. Choose an angle that feels comfortable when you're sitting in your normal driving position. Consider your seat position, distance to pedals and most importantly…. how your arm hangs on the window frame. You have to have the proper "attitude" when cruising and you can't do that without the proper stance. I've seen articles showing a broomstick or a piece of conduit and a pie pan mockup. Use a clamp at the dashboard. (Using the column itself is a little cumbersome.. it's too long without the hole in the floor and it's heavy
and hard to handle.) Move your dummy column around…try different heights… get comfortable. When it "feels" right make some marks at the floor end. (Remember your column has tilt also to make your ride more comfortable). This measurement process should give you the probable vertical (up and down) center of the cut out in the floorboard. I then found the centerline between the column mounting holes under the dashboard and then using a framing square and a straight edge…. Projected this line down to the floorboard. This should give you a good center horizontally (left to right). On the outside of the cab, I used the centerline of the steering box shaft and marked this centerline on the lower part of the firewall. A little ciphering and measuring showed these two lines to be within 1 inch of each other with the steering box a little more ‘inboard' than the column center line. No problem… linkage will handle that easily.
Cutting your hole….
My hole fell almost at the top of the sloped portion of the floorboard where it meets the firewall. A little higher than the original hole if I remember correctly. I cut a hole approximately 3" high and 6" across, giving me plenty of room for adjustment later. Since I had to make a patch panel anyway.. a 3"x6" is just as easy to make as a 2"x2" and a heck of a lot easier to work in…Make your cut in the floorboard using a torch, recip saw, hole saw…. Your floorboard…. Your choice… your level of finish will determine your choice. Mine was torch since I'm working with a shell of a cab and no paint, carpet etc to worry about.
Mounting the column…..
There are several methods of mounting the columns and I'm sure you will have your own ideas. I fabbed up a lower mount from a muffler clamp and a piece of 11ga sheet material approx. 4" square. I simply welded the clamp portion to the 11 ga. Material and this bolts to the floor (see picture) the clamp then tightens around the column.
At the top of the column I welded two 7/16 bolts approx. 7" long to the saddle that bolts to the column. These bolts are on the correct angle to extend up through the original column mount holes in the dash. They also support the front portion of the hanging pedal assembly (another article). If you did your bolt welding properly on the saddle, the column will be at the correct position (shifter at 1:00 and switch at about 2:30… turn signal switch at 9:00) Be sure to use the copper bolts that came with the column and saddle. These give you the breakaway ability should you try to tilt your column with your breastbone. The other piece in the picture with the lower clamp is the patch panel for the floorboard. Yours of course, will match your hole… I used light gauge metal, probably 18 gauge, for the panel…cut my circle with a Greenlee punch. A neat item that Electricians use to punch holes in electrical boxes. They come in sizes from ½" up through 6", they're not too ex
pensive and cut a clean neat hole. I also cut out to the edge so I could put it around the column after it was installed. The same bolts that hold the clamp hold the panel. (see picture below) Body sealer or caulking will seal the edges later
Connecting to the steering box is also a matter of preference. I've seen some nice home made linkage using u-joints from front wheel drive vehicles steering linkage and ¾" rod stock… they were substantially strong and nice looking. I personally used Borgenson joints and shafts. Nice shiny polished stainless stuff that will look good against my painted frame and suspension. They have all the proper splined fittings and the short shafts you will need. Just be sure to chose the ends with the correct spline count and be careful measuring the intermediate shaft length… I used two universals and a 4-1/2" shaft and it fit perfectly. You shouldn't need three universals but if you do you will have to add a support in the middle to prevent the joints from rolling and binding up. Borgenson has a very extensive catalog that explains everything in laymen's terms The steering linkage is of course one area where you don't want to scrimp at all…if you must err…do it on the safety side
That's about it. (Except for paint and wiring). Stick it in… bolt and clamp it down (don't forget the patch for the hole in the floor. Caulk or use body sealer on the patch panel to keep out the elements. Hook up your steering linkage and you're ready to lay under the truck for several hours figuring out your shift linkage… another article I'm sure.