Wednesday, February 19, 2020

Adjustable Steering Wheel

(Posted on FB 2/8/20)

PROJECT 51: Adjustable Steering Wheel. All the way back in 1936 MG was putting telescoping steering columns in their cars to allow drivers with shorter legs to not have the wheel right in their face when they scooted the seat forward. There was also a small amount of up-and-down adjustment, but both required a wrench to make any change.
When I got my car home and discovered the cool telescoping feature, I loosened the clamp and tried to slide the wheel. It wouldn't move in or out, and I figured it was just rusted from all that Washington rain it had probably seen.
After taking the whole steering column out of the car, I was finally able to knock out the externally-splined shaft (which attaches the steering wheel to the internally-splined column) using a four-foot-long steel bar. I cleaned the rust and grime from inside and outside, but the spline was still not able to slide into the column by more that an inch and a half (it is supposed to have five inches of adjustment). Further, deep-root-cleaning with stiff wire brushes did not help.
Then, as the light hit the splined shaft just right, I saw what I first thought must be an optical illusion. The rows of splines, which must be dead-straight for the shaft to slide freely, had a twist! Somehow, Brutus had managed to put enough torque on the 7/8" diameter, 1/8" wall steel tube to put a permanent twist in it!
With the wire-spoke design of the steering wheel, the twist could not possibly have been introduced by just turning the car's wheels. The spokes would have bent long before the spline twisted. I have to guess that the nut holding the wheel to the shaft was so rusted that it took a three-foot bar on Brutus's wrench and a good deal of his strength to finally break it free. (Had Brutus slid the once-straight spline shaft down into the column before cranking on it, it would have been supported near the end, and not left five-inches exposed to absorb the torque he was putting into it.)
I tried a Brutus-like brute-force approach to straightening the shaft—including heating it with a torch—but I never really held out much hope. I did get the splines a little straighter, but as mentioned, they need to be dead-straight to slide easily into the column.
Fortunately, I can buy a new splined shaft. Un-fortunately, it's one more $100+ expense that I hadn't anticipated. (Those are beginning to outnumber the ones that I had!)

Adjustments for the TD's steering wheel.

Twist in spline shaft.

Brute-force attempt to straighten the spline shaft.

Brute-force plus heat.

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