GM tilt column experts!

Discussion in 'Wrenchin' Secrets' started by buick64203, Oct 8, 2018.

  1. buick64203

    buick64203 Just plum crazy Staff Member

    I have a long term issue with my Aquamist 4 speed car and I think I had an epiphany...

    This issue has slowly moved up on the things to do list and I was reminded of it this past weekend when I was driving it around. Just to give you some background- The problem is that I can turn the car off and remove the key regardless of weather the trans is in reverse or not. The car has the correct reverse lockout rod and the column rotates to "park" like it should. But it doesn't seem to matter. Whatever prevents the key from being turned to LOCK is either missing or as I suspect, a wrong year part has been installed.

    The car has its original 69/70 style column with the large upper bearing pre load nut. The 71 and up columns don't seem to have this nut and use the large spring for pre load. But I digress...

    So recently, I located a 69/70 style tilt column for the beater so I can upgrade it to tilt. In rebuilding that column, I noticed that the ignition actuator rod (that's the long rod that goes from the rack to the switch) had a "Z" bend in it. I never saw an actuator with that kind of bend in it. Ive only seen the straight style. I rebuilt this column and it works the way it should. So now Im thinking that maybe someone may have put the incorrect, straight style rod in my Aquamist column. That's the only thing that makes sense to me.

    No, I haven't taken the Aquamist column apart. I want to make sure I have everything available when I do take it apart. Better to be looking at the pats you need than to be looking for them.

    So....can anyone verify my hypothesis? And does anyone have a spare actuator rod with the Z bend in it ?
  2. Gallagher

    Gallagher Founders Club Member

    I can't help you with your problem, because I've only been as deep as the lock cylinder one time on a '71, and that was 28 years ago.

    I do have questions though.
    Didn't you buy a tilt column off Ebay a year or so ago? Now you recently located another one?
    Are you sure you don't have the rod you're looking for laying around somewhere?
  3. TorqueMonster1

    TorqueMonster1 Making My GS Great Again!

    I suggest you get with Brian Trick. He seems to know these tilt columns inside and out. Hopefully the answer will get posted here for others in the future. Mark
  4. mrolds69

    mrolds69 "The Cure"

    It kind of sounds like a worn key or tumbler problem. That's when you can typically remove the key in any position...when it's worn out. I know the 69/70 columns have a different either spring, or attaching method for the spring that pushes the locking pin into the plate under the steering wheel to lock the wheel. I think the 69/70's use a phillip's head screw to hold the spring, and later columns use a hex head screw that you can get tighter. I know one earlier column I worked on, that spring moved all around and the pin didn't have really good power from the spring to extend into the locking plate. I know there is that difference in the early column, I know the bearing difference you mentioned. I've never really noticed the rod difference because I usually just take apart one column at a time and don't mix parts. 'Course it could be a sector gear wrong tooth alignment deal, it's very common. I thought you fixed that column before?
  5. buick64203

    buick64203 Just plum crazy Staff Member

    Frank- I started to get into the issue a few years ago. I wound up throwing a new lock cylinder in it hoping that was the issue but no luck. Obviously, I need to go deeper into the column.

    Mike- Most of the tilt columns Ive bought were of the 71-72 variety without the bearing nut. Those all have had straight rods. This last one I bought for the beater just happened to be out of a 69 Chevelle SS 4 speed car. And that's when I noticed the actuator rod differences. I have boxes of steering column parts but all the rods I have are straight. I'll have to ask Brian and see what he says. I hate to take it apart and not have all the right parts at the ready if need be.
  6. Gallagher

    Gallagher Founders Club Member

    Can you take the one with the bend back out of the beater and make a new one based off of it?
  7. Bluzilla

    Bluzilla a.k.a. "THE DOCTOR"

    If what you are experiencing is that the ignition cylinder can rotate fully into the "off" position as well as the "accessory" position with the "gear selector lever - shift bowl/shroud" in any position as it rotates throughout its full travel, .... then there is definitely an issue with the ignition actuator interlock system.

    That system is very basic in that the lower shift bowl/shroud has a raised section cast into it to prevent the ignition actuator system from returning to the "off or acc." position until the bowl/ shroud is in the park position.

    Once the ignition cylinder is rotated clockwise past the "off" position (i.e. ignition or start position), the actuator rod is pulled toward the driver and will then clear the raised section of the bowl/shroud allowing the bowl/shroud to rotate throughout it's normal shift pattern. Once in any gear position but park, .... the raised section of the bowl/shroud blocks the ignition actuator rod from returning to the off position (away from the driver).

    I believe if someone were to have removed the raised section of the bowl/shroud, then the ignition actuator rod would be free to move throughout it's full range (including off and accessory) regardless of what position the bowl/shroud is in.
    Of course this would also hinge on the correct ignition cylinder/ignition rack/ignition actuator rod, and ignition switch phasing.

    I grabbed a few parts from a 1970 Skylark/GS tilt steering column I'm about to rebuild and snapped a few photos to help explain.
    The first photo shows the ignition actuator rod in the "off" position, ..... where it also keeps the bowl/shroud from rotating out of park.
    The second and third photos show the ignition actuator rod in the ignition (run) position (toward the driver) allowing the bowl/shroud to rotate throughout it's full gear selection range.
    The important note here is that in these last 2 photos the ignition actuator rod is being blocked from returning to the "off/acc. position (away from the driver).
    I hope this helps to understand the interlock system.

    IMG_4867.JPG IMG_4868.JPG IMG_4869.JPG

    Last edited: Oct 22, 2018
  8. Bluzilla

    Bluzilla a.k.a. "THE DOCTOR"

    I just thought I would add a photo of the correct ignition actuator rod for the tilt column.

    Because the upper portion (towards the driver) of the ignition actuator rod is in the 9:00 position, and the actual ignition switch portion (down toward your feet) is in the 12:00 position, .... the ignition actuator rod will always have a double bend in it.


    Last edited: Oct 21, 2018
  9. buick64203

    buick64203 Just plum crazy Staff Member

    Thanks Larry! That clears it up! After looking at that, the only thing I can think of is someone must of modified the lower bowl somehow. Never ceases to amaze me the odd stuff people do to cars. If so, what was the point of it? This whole thing has been a mystery since I bought the car. And it looks like I ran out of nice weather this year. Oh well, there's always next year! Too many projects, too many cars, never enough time
    TorqueMonster1 likes this.
  10. dynaflow

    dynaflow shiftless...

    Thanks for pics/explanation...added to my Tilt Column folder...
    TorqueMonster1 likes this.

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