Steering Seizure

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Steering Seizure

Early in the last race of the Lime Rock Historics I experienced a bit of resistance in the steering of my Macon MR7. It started out as a stiffness on the straight that tended to go away in the corners and then got progressively worse. By the end, I had to slow way down to finish safely. When I came into the pits it was desperately difficult to make the sharp turn into the paddock.

To me, it felt like the steering rack was packing it in. I was sure my old customized LBC (Little British Car) steering rack was dead or dying. I was rather bummed about the whole thing. I got a bit grumpy I guess. I put the car in the trailer without even trying to diagnose the problem. I told myself “I’ll deal with it another day.”

Two weeks later and I still hadn’t even taken the Macon out of the trailer. I was talking to my friend Stephen Morici and he listened to my tale of woe. He told me of a time when he experienced something similar in his Cooper T67. For him, it was as basic as hitting the pillow block behind the dashboard with a shot of WD40. I swear Stephen, I was actually listening! The explanation just didn’t “feel” right to me. Next time, I promise I’ll be more attentive.

Sure enough, when I got to look at my car it was indeed a problem at the pillow block behind the dash.

When I got it apart and looked at it there were obvious signs of spalling. With the pillow block removed from the system, the steering force returned to normal. It wasn’t the rack!

I was well chuffed at this good news!

On my car, the pillow block does not have a bearing. It has a bearing surface I guess, but is bearing-LESS. So it is just the steel shaft riding on aluminum. When I originally assembled it, I greased it well and forgot about it. I just didn’t think about how it could need periodic re-lubrication.

Now I was a bit miffed at my failure and I decided to not only fix it (which would have been quite simple, even at the track) but to also improve upon it.

Because I fabricated a new steering column with a welded in collapsible section (for safety), I could not use an actual bearing on the steering column. There would be no way to install it without cutting the steering column and welding in a coupler. That was an option of course, but I thought I had a way to work around it and still have it be nearly maintenance free.

First I cleaned the steering column itself. (Photo above is with the column mounted in the lathe prior to cleaning.) I used Muriatic Acid to remove the deposited aluminum and then polished the shaft with 240 grit emery paper while spinning on the lathe.

My improved design featured an Oilite bronze bushing inserted into the original aluminum pillow block.

It would still be bearing-less, but Oilite bronze is designed to release lubrication when force is applied to it. It may need a refresh on the lubrication eventually, but experience indicates that time would be years in the future, if ever. But I’m feeling very belt-and-suspenders about this so… I decided to install a Zerk fitting so I could inject some grease whenever I wanted.

The only real trick here would be splitting the Oilite bushing in half so it could be installed around the steering column. A hacksaw takes care of that and cleanup is managed with a needle file.

One more feature you might notice is the plate I added to retain the bushing in the block. I was concerned it might walk out during use (once I split it and the installation pressure was so drastically reduced).

All greased and bolted up and it feels good turning the wheel with the car on dollies. The true test will be once it hits the track next time.

Signing off at-speed…

-STEFAN

1 Comments

An overly complex solution, with it’s own failure points, to solve a simple problem.
Substitute your friends WD40 with a little oil or anti-seize once a year and it would be fine forever. Clean the friction points each winter with some brake cleaner.

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