1970 Corvette Standard Steering Column Length

[David S.]

Hi All,

I went to install an original standard steering column in my 70 vette. To my surprise the column did not fit. The shaft is about 1/2 inch shorter than the shaft of the existing tilt column (that I removed). Needless to say it would not go into the rag joint.

The column itself is the late 69/70 version and the steering box and rag joint were just rebuilt/ restored by Bairs.

Does anyone have any idea what the problem is here?

Thanks,
Dave

[Jim S.]

Re: 1970 Corvette Standard Steering Column Length

First of all the overall length of a 1969 or 1970 Corvette standard (non-adjustable) steering column should be 39.7 inches from tip of the bare upper shaft to tip of bare lower shaft. No hubs or flanges attached. There was a difference in the lower column bearing between early 1969 Vette strg columns and late 1969 or 1970 strg columns. (This lower bearing difference did not affect the overall length of the steering columns.)

On early 1969 standard steering columns there was a clamp with a nut and bolt on the lower steering shaft. That clamp was attached with about a 0.25 inch gap to the lower bearing. (Don't ask me why the 0.25 gap.) The length of lower steering shaft from the edge of the clamp to the end of the lower steering shaft should be 3.2 inches.


On the later 1969 and all 1970 steering columns the amount of lower steering shaft that extends beyond the retainer the holds the lower column bearing in place should be 4.5 inches. (These columns did not have a clamp.)

Now, here is the important part. 1969 was the model year were a new second generation of collapsible, energy absorbing steering columns were introduced. As part of the safety design, the steering shaft was assembled in two pieces. The lower steering column steering shaft telescoped over the solid upper steering shaft in a severe frontal collision. The two shafts were precision formed and assembled with generous overlap. They were kept in place by a small amount of injected plastic material.

What has happened is that the lower steering shaft has telescoped up into the steering column by the one-half inch that you are reporting. There are no safety implications but you will need to draw the steering shaft back out of the steering column. Try to pry the shaft back out without hammering or pounding on it. Hammering the shaft could result in damage to the steering column bearings.

You may ask, "How do I draw the lower shaft out of the steering column?" I would suggest installing the flange on the lower shaft and try to leverage the shaft out of the lower bearing by the needed 0.50 inch. BTW, here is a great opportunity of other NCRS members to share how they may have extracted the lower shaft with hands-on experience.

Jim

[David S.]

Re: 1970 Corvette Standard Steering Column Length

As always. Thank you Jim!

[Alger R.]

Re: 1970 Corvette Standard Steering Column Length

Jim,

I want to thank you for the tilt-tele disassembly instructions that you have on-line. "Priceless"!
As to extending a collapsed telescoping shaft back to its original length this is what I did. (The shaft was out of the car)
After measuring the total length from center of the yoke toend of shaft, I realized it was two short. I then purchased a long rod at the nearest hardware store of theproper diameter and inserted it into the end of the shaft and pounded it with a hammer until the smallersolid shaft telescoped back out to the proper length of 31 inches yoke centerto end of shaft. The plastic that was originally injected in the two alignment holeswas lost but the shafts are so tight that I felt there was no need to worryabout it.
AL