Tilt/tele versus straight column

[D S.]

Dilemma! I am assisting a friend with getting his 1969 Corvette back on the road. His car is originally a straight steering column so he bought a complete tilt/telescopic to replace it for comfort reasons. After we pulled the straight one out and test inserted the T/T we noticed that the shaft from the firewall to the steering box is at least six inches shorter than the straight column so it does not even come close to reaching the steering box. Is something missing? We thought these things were direct bolt ins.

Thanks,
Scott

[Alan S.]

Re: Tilt/tele versus straight column

Hi Scott,
Perhaps the 'Energy Absorbing' section of the column has been compressed.
Regards,
Alan

[D S.]

Re: Tilt/tele versus straight column

Alan, after I posted this thread and was sitting here thinking about it and looking at the photos we took of the two columns together that very DUH thought hit me. I called my friend back and asked him to put the flat sides of the shaft in a vice and pull on the column. Sometimes my IQ peaks at 1 and then it ricochets back to zero. Like today.

Thanks,
Scott

[Jack H.]

Re: Tilt/tele versus straight column

It's pretty common for used columns to have come from 'crash' cars... That typically results in the lower shaft being 'short' because it compressed as it was designed to (Energy Absorbing feature). You're on the right track to properly re-extending the column to make it fit/work again!

[Martin N.]

Re: Tilt/tele versus straight column

Do the plastic "shear pins" control more than the forward and rearward motion of the column / shaft? Do they need to clamp the end of the shaft in a vise and see if there's resistance in sterring wheel movement left to right? It's been a long time since the body shop days.

Marty

[Jim S.]

Re: Tilt/tele versus straight column

Careless handling, shipping, or prying on the flexible coupling can cause the steering shaft to telescope back into the steering column. The steering shaft is constructed in two pieces with injected plastic holding them to the correct length. There is a large metal to metal overlap between the solid (upper) shaft and the tubular (lower) shaft so there is no danger in losing steering integrity. If the plastic pins are sheared, you might develop a very slight looseness in the overlap joint.

With the plastic sheared, the lower shaft will not slide out of the column because Saginaw used a long tool to reach up inside the tubular lower shaft and upset the end of the solid upper shaft. The overlap and upset end is inside the steering column in the area of the ignition switch as shown above.

1969 through 1976 T&T columns should have 4.70 inches of steering shaft length sticking out from the lower column bearing.

1977 and 1978 columns should have 4.90 inches sticking out.

1979 through 1982 columns should have 5.00 inches sticking out.

I haven't quite figured out why - but the shaft compresses into the column a lot easier than it comes back out.

Jim

[D S.]

Re: Tilt/tele versus straight column

Jim, thanks for providing us the lower steering column schematic. The friend who had the problem took my suggestion to put it in a vice and pull on it. It didn't budge. He squirted silicone spray liberally into the barrel and it still didn't extend. He told me as a final resort he took a hammer and pounded on the end of the shaft and it popped out. I certainly wouldn't have gone to that extreme but it worked for him. I just hope he didn't damage anything on the end. I haven't been back to look at what he's done. You know how that goes....he has a lot of work to do and it's natural to want to pitch in and help. From personal experience I think the work to be done inside the Corvette and under the dash is a one person job. Besides...his garage isn't air conditioned and it's humid and in the upper 90s here in Texas.

[Jim S.]

Re: Tilt/tele versus straight column

The problem with hammering on the lower shaft is that you could damage the ball bearing races that support the upper end of the steering shaft. Check to make sure that your steering shaft rotates smoothly and is not rough.

I should have mentioned this before.

Jim