78 steering column
Thread Starter
Heel & Toe
Joined: Jul 2011
Posts: 16
Likes: 0
From: Hoquiam WA
78 steering column
Ok guys need some help. Working on the wifes 78, the car had been sitting out in the north west weather and moister inside. She all dry and I have been working on the body for paint. Anyway I went to move it today and the ignition switch is froze cant get it to turn at all. So how do I tear this beast apart to rebuild it. Please help.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 112
From: Saginaw Michigan
First, let's get our terminology correct.
The ignition lock cylinder is the part in the column head where you stick your ignition key.
The ignition switch is located down under the dash on top of the steering column jacket. It is difficult to access (making it difficult for a thief to hot wire your car.)
The ignition switch is actuated by a rod that extends up into the column head. The ignition lock cylinder rotates a small plastic gear which moves a small die cast rack. The rack is attached to the rod and the motion of the rod moves the switch to its various positions: START, RUN, OFF, OFF-LOCK, ACCESSORY.
So first, with the key in the lock cylinder, the lock cylinder doesn't move in any direction. The key and/or lock cylinder is defective.
The key in the lock cylinder moves to START, RUN, OFF but doesn't allow the key to be rotated to OFF-LOCK (or ACCESSORY) and the key removed from the lock cylinder.
You need to trip the small lever next to your ignition key to allow you to reach OFF-LOCK and ACCESSORY.
The key in the lock cylinder moves to various postions but nothing happens. The die cast rack might be broken and needs to be replace.
The ignition lock cylinder is the part in the column head where you stick your ignition key.
The ignition switch is located down under the dash on top of the steering column jacket. It is difficult to access (making it difficult for a thief to hot wire your car.)
The ignition switch is actuated by a rod that extends up into the column head. The ignition lock cylinder rotates a small plastic gear which moves a small die cast rack. The rack is attached to the rod and the motion of the rod moves the switch to its various positions: START, RUN, OFF, OFF-LOCK, ACCESSORY.
So first, with the key in the lock cylinder, the lock cylinder doesn't move in any direction. The key and/or lock cylinder is defective.
The key in the lock cylinder moves to START, RUN, OFF but doesn't allow the key to be rotated to OFF-LOCK (or ACCESSORY) and the key removed from the lock cylinder.
You need to trip the small lever next to your ignition key to allow you to reach OFF-LOCK and ACCESSORY.
The key in the lock cylinder moves to various postions but nothing happens. The die cast rack might be broken and needs to be replace.
Thread Starter
Heel & Toe
Joined: Jul 2011
Posts: 16
Likes: 0
From: Hoquiam WA
More Info.
Thanks for the help Jim.
Here is what happened. The car was sitting out in our nice wet climate here in the Pacific NW. anyway she got went inside.( leaking T top) so this went un-noticed for quite awhile. When I found it and went to move it the key was real hard to turn. I got her inside and dried out. I started to get her ready for paint. The Batt was disconnected so I just left the key in the on position. so I could move her around the shop. I got most of the large panels stripped. I had not started her in quite awhile (before I moved her in to dry) So when I went to start her the key again was very hard to turn she started but would dye as soon as I let off the key. I turned off the key the release lever would not move but the key come out. Now the key will not turn at all. I suspect lots of corrosion in all of it. I guess I should pull the column out and start with the switch make sure it is ok then work my way up. What do ya think. any help is greatly appriciated.
Here is what happened. The car was sitting out in our nice wet climate here in the Pacific NW. anyway she got went inside.( leaking T top) so this went un-noticed for quite awhile. When I found it and went to move it the key was real hard to turn. I got her inside and dried out. I started to get her ready for paint. The Batt was disconnected so I just left the key in the on position. so I could move her around the shop. I got most of the large panels stripped. I had not started her in quite awhile (before I moved her in to dry) So when I went to start her the key again was very hard to turn she started but would dye as soon as I let off the key. I turned off the key the release lever would not move but the key come out. Now the key will not turn at all. I suspect lots of corrosion in all of it. I guess I should pull the column out and start with the switch make sure it is ok then work my way up. What do ya think. any help is greatly appriciated.
Last edited by oldtrkguy; Jul 4, 2011 at 08:07 PM. Reason: sp
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 112
From: Saginaw Michigan
From your latest description it sounds as if you are going to need both an ignition lock cylinder (and keys) as well as a new ignition switch. I assume that you have a T&T steering column (most 78s had T&T columns.)
Ignition lock cylinders are the same for 78s regardless of steering column type. Ignition switches are unique, T&T switches operate in the opposite direction from the standard column switches.
Jim
Ignition lock cylinders are the same for 78s regardless of steering column type. Ignition switches are unique, T&T switches operate in the opposite direction from the standard column switches.
Jim
Thread Starter
Heel & Toe
Joined: Jul 2011
Posts: 16
Likes: 0
From: Hoquiam WA
thanks Jim
Jim thanks for the help I was kinda expecting that. Going to pull the column on Friday. I think the Cylinder is going to be a bear as I can't turn it to push the release pin. Have to see about drilling it out.
Le Mans Master
Joined: Jul 2000
Posts: 6,001
Likes: 112
From: Saginaw Michigan
There is a small plastic tab that is part of the lock cylinder.
The tab extends when the ignition key is in the lock cylinder and the cylinder and key are rotated to the OFF, OFF-LOCK, or ACCESSORY positions. With the tab extended it engages a key buzzer switch in the steering column head and closes the switch contacts.
The problem with the plastic tab is that it could damage the key buzzer switch if you try and pull the lock cylinder with the tab extended.
I also found this comment in one of my papers:
"I believe that ignition lock cylinders that are installed in GM locking steering columns (1969+) are more secure (than the old in-dash lock cylinders) and drilling the cylinder is not an option. These lock cylinders must be removed by removing the steering wheel and further disassembly of the steering column is required."
Jim
The tab extends when the ignition key is in the lock cylinder and the cylinder and key are rotated to the OFF, OFF-LOCK, or ACCESSORY positions. With the tab extended it engages a key buzzer switch in the steering column head and closes the switch contacts.
The problem with the plastic tab is that it could damage the key buzzer switch if you try and pull the lock cylinder with the tab extended.
I also found this comment in one of my papers:
"I believe that ignition lock cylinders that are installed in GM locking steering columns (1969+) are more secure (than the old in-dash lock cylinders) and drilling the cylinder is not an option. These lock cylinders must be removed by removing the steering wheel and further disassembly of the steering column is required."
Jim
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