Lower Steering Column

William,

Is that your opinion of period madated safety upgrades in general or just this one?

The first real resistance on an E-type are steering rack and picture frame. What happens to subframe fore-aft tubes depends on many factors, but given their mounting arrgt there's a decent chance they will buckle and absorb energy. The lower column will transfer energy directly to the upper.

30 years ago when I used to cruise junk yards for parts, I saw cars w/ crumpled front subframes and upper colums punched into the driver's space, presumably by force of the lower column. That's my only crash test data.

Apologies for intiating a safety debate, I was just trying to establish if S2 column would fit.

Thnx to all who weighed in w/ opinions.

Joseph, If you are involved in an accident with the force to push the steering column up into your body the later column is unlikelly to be of any help!

Mike,

Interesting. I'm mostly concerned about getting speared by the S1 one piece lower column. You raise another issue- driver sliding forward into the wheel/ upper column. You're saying the S2 upper column support bracket will actually break away under less force than the s1, assuming it's mounted correctly.

SNGB concurs the S2 lower column is a direct substitution for the S1- only difference being the sliding joint which has a small pin that shears on impact. The lower u-joint must be replaced w/ double yoke type.

Think I'll swap it since mine also has worn upper spline. Thanks for the help. and advice.

Mike the lower col. on the S2 is also collapsable. It is a two part affair with nylon bushes not a single shaft like the S1.

To answer a whole lot of questions, in no particular order:

The S2 lower can be substituted for the S1. In fact. I'm not sure if there's any mechanical difference between them.

Shock absorbtion is provided by the collapsible S2 UPPER column.

The S2 upper can be installed in an S1, but you need to make some mods. You would discard the S1 column support, and build a reinforced mount on the bottom side of the instrument panel. I did this on one of my cars, long gone so I can't see how we did it. The mounting ears on the S2 column are frangible, meaning that they break away under extreme stress. The dash side of the mount is rigid to support react this effect. That means that if you work out a means of bolting it in, the safety features are preserved.

George,

I think maybe we agree; The S1 lower column is rigid, the upper support tube is not. The S2 upper support tube is more rigid and the column is not.

Point I was making is rigid upper support tube, while better, may not be essential to cause lower column to collapse.

Thanks for responding.

Koseph it is actually the other way--the S1 Column is more rigid by a lot. The S2 will collapse quickly on impact.

George,

I see your point. The S2 upper column tube is beefed up to provide a reaction point for the lower. The S1 tube looks flimsy.

But aren't the first few milliseconds after impact inertia governed? If the mass is equally divided, when the bottom accelerates, won't the top mostly stay put until it slides all the way in, at which point reaction force is mobilized? Looks like about 8 in. before it bottoms out -roughly chest depth.

Occurs to me grease is thixotropic and could offer high resist during intertial phase. Motor oil is Newtonian, would be better lube.

High speed impact I'm in trouble either way because front subframe is in my lap, but the thought of being impaled in a 25mph crash does detract from my driving enjoyment.

Joseph hopefully someone will measure for you as I do not have a sample of both. That said you will obtain little if any extra safety by that operation. The series 2 lower column was coupled with a special collapsable upper column that worked together. Putting in the lower without the upper as I said would do little if anything.