To my other GT6 pages

December 25, 2020

Steering Column

The steering column in the GT6 was apparently used across a range of both small and large chassis Triumph cars. There seem to be some mounting variants, and later columns have provision for a steering lock, but the design is mainly the same.  My column was filthy, tired, and sort of loosey-goosey, but it appeared to be complete.




The column is made up of an outer aluminum housing holding a telescoping shaft.  The telescoping shaft consists of the outer shaft, which is connected to the steering wheel, and an inner shaft, which connects to the rack and pinion box.  The two shafts are held in relative position by a friction fitting. I believe the idea is that in a front end collision, the inner shaft would slide rearward against the friction, absorbing some of the impact energy.  This is only good for a few inches of travel, though.  After that, it appears that another part of the energy would be taken by crumpling the thin, soft aluminum housing.  This was Triumph's version of the collapsible steering column.




The outer column housing carries the column controls--turn signals, headlight hi/lo beam, and the horn button parts.




Also inside the column housing are a pair of bushes that the shaft rides in.  Judging from the play in my steering wheel, I knew the bushes were worn.  So, out they came.  The original bushes are a steel cylinder inside a rubber jacket.  Inside the steel is a nylon lining , which is the actual bearing surface.  The rubber jacket has a small protrusions that fit into holes in the column housing. It can be a bit of a wrestling match to get the resilient bushes to move.  Cutting or drilling away the rubber protrusions seems to help.




In addition to wear of the nylon insert, my shaft showed signs of wear.  I could see it, feel it, and measure it.




New factory type bushes can be bought, and they probably aren't that expensive.  On the other hand, I didn't really see the advantage of the multi-layered bushes.  A simple solid bushing, made to press fit in the housing should do the job, and maybe even tighten up the steering a bit by eliminating the resilient rubber layer.  I chose to stick to plastic for the bearing surface, though.  This is a rod of Delrin, an acetal plastic with good stiffness, good dimensional stability, and high natural lubricity with steel.  The bushes shown are the originals.




The Delrin bushes were machined for a pretty tight fit in the housing.  The fit was such that I didn't see any need for locating devices like the nubs on the originals.  They are a nice slip fit on the shaft.




There is some leeway in exactly where the bushes go in the housing.  I took advantage of that and put the bushes a little farther apart than stock.  The main reason I did this is so the bushes don't ride on the areas worn by the original bushes, but I think the slightly wider spacing may also improve the solid feel of the steering wheel.  I powder coated the housing before installing the bushes.  I decided to help the natural lubrication by squirting in a little graphite powder in and around the bushes.  The result is a very nice tight but smooth rotation of the shaft in the housing.




Next out of the tub of steering column parts was the electrical controls. 




A general cleaning made them look good enough to use, but I wanted to make sure they worked.  All was good except the high beam circuit.  It was frustratingly intermittent, but I couldn't reproduce it on demand.  I thought the problem was at the bullet terminal end.  Replacing the bullet fixed it.

 


Ready for install.  One interesting factoid: the fixing screws for the controls, which appear to be 8-32 are actually a rather odd 8-36.  Not odd, exactly, since 36 is the standard UNF pitch for a #8 machine screw, but it's not very common.  I'm sure some well-intentioned folks have jammed an 8-32 in there.




Then I checked the turn signal canceling function.  It depends on this little clip fastened to the upper steering shaft.




Then it was the escutcheons that cover the switches.  They are just plastic shells that improve he esthetics.  The one on the right was just cleaned up with soap and water.




This is probably an example of where I maybe should have left well enough alone.  I thought the white legends on the escutcheons were a little natty, so I removed them, used some plastic polishing compound to brighten up the plastic, and applied new waterslide decals.  Frankly, after the work to improve them, I don't think they look any better, and maybe worse.  Certainly the outline of the decal is more visible than before.  Ah, well.  Live and learn.




These little inserts have the threads for the screws that hold the escutcheons.




The escutcheons were applied...




 ...and then the horn contact ring goes in so its wire can join the others.  A couple of tabs in the housing bend down to hold it in.




This little piece is a cover to protect the wires as they come out of the column housing.




Then it was time for some mounting brackets.  The parts at the top are for the rear mount (closest to the steering wheel), while the parts at the right are for the frontmost mount. The black parts are powder coated, the silver parts are stripped and replated.




The rear mount has a little clip that snaps around the housing.  Since the aluminum of the housing is so soft, it gouges very easily.  I put little bands of galvanized steel sheet under that clip and under the band for the wire protector.  The bands protect the aluminum.




The front bracket gets new felt strips that gently cradle the column.




These parts close off the lower end of the column housing.




The last thing to do is install the inner (lower) steering shaft.




There is a cutout in the outer shaft that allows the friction fitting to bear down on a flat on the inner shaft.




I've been holding on to this mystery part for over a year now.  I finally realized where it goes.  It's a nut plate for the rear column bracket.




There were a couple of other items in the steering column bin.  The horn button really goes more with the steering wheel, which I'm not doing right now, but I cleaned it up anyway.




The last piece was the little U joint that goes between the column and the rack and pinion. I took it apart, cleaned up the rust, and powder coated or replated the metal parts.  The rubber parts seemed good enough to re-use.




This dude goes on the shelf.




As sometimes happens in these kinds of projects, I had a part left over.  It's a cardboard tube that was found on the lower part of the column housing.  You can see it in the first few pics above.  I can see no earthly purpose for this tube.  After a search, consensus seems to be that it may have been some kind of install gauge that was just left in place.  I'll keep it for a while in case I'm wrong.




This was an enjoyable project, and was good for a couple of pleasant days in the nice warm shop.  Cost was minimal--probably under $20, including consumables.

Comments to Ed at elhollin1@yahoo.com

To my other GT6 pages