1974 C10 Ignition switch replacement

[Rotten 1]

This weekend's project is to replace the ignition switch on my '74 C10 with a tilt steering wheel. When I turn the key the engine sometimes turns over, and sometimes nothing but the blower motor running. Previous owner ran a direct wire to the starter and tied it off near the battery so I can "hotwire" it and get things running, but it's time to fix this.

From what I have read and found on YouTube it's a matter of a couple bolts to drop the steering column, then trying to get to two more bolts on top of the steering column (with a wrench and my big hands), then pulling the old one out and inserting the new one.

Any particular hints to make this easier and less bloody?

Thanks

 

[75gmck25]

It may be the electric switch down low on the top of the column, or it may be a problem with the rack on the end of the lock cylinder.

When you turn the key it moves a toothed “rack” on the end of the cylinder, owhich then pulls a rod up and down the column. On the other end of the rod is where the electric switch is connected.

The ignition rack is made of pot metal, and it is common for it to crack or break, and not reliably pull the rod up and down. The GM ignition rack is a cheap part, but takes a lot of disassembly of the upper column to reach it. There are numerous articles on the web that explain exactly how to take it all apart and get it back together.

 

[Rotten 1]

It may be the electric switch down low on the top of the column, or it may be a problem with the rack on the end of the lock cylinder.

When you turn the key it moves a toothed “rack” on the end of the cylinder, owhich then pulls a rod up and down the column. On the other end of the rod is where the electric switch is connected.

The ignition rack is made of pot metal, and it is common for it to crack or break, and not reliably pull the rod up and down. The GM ignition rack is a cheap part, but takes a lot of disassembly of the upper column to reach it. There are numerous articles on the web that explain exactly how to take it all apart and get it back together.

I have not done the deep dive yet - but it looks like this is not an easy afternoon to diagnose, but maybe more of an adventure. I'm ordering the rack and will replace everything (rack and switch) once it comes in.

Thanks guys

 

[legopnuematic]

As 75 said, the rack is generally most suspect.

My 76 was in the process of breaking for years before it finally completely broke.

The switch is easy to test, once unbolted from the column, but still hooked to the wiring, use a small screwdriver or pick to run it through the positions and if it functions fine it should be fine. Which points back to the rack.

 

[DoubleDingo]

I have not done the deep dive yet - but it looks like this is not an easy afternoon to diagnose, but maybe more of an adventure. I'm ordering the rack and will replace everything (rack and switch) once it comes in.

Thanks guys

It's not incredibly difficult, but involves some time and patience. If your wheel has any slop when turning, meaning column slop, that is the time to tighten the bolts that keep it all tight. I didn't do that on my Jeep Cherokee when I first replaced the rack and sector, and had to go back in to tighten the bolts. Jeep columns are the same as GM columns. I didn't believe it when told this, but found it to be true. I forget where it is on here, but someone posted a detailed step-by-step directional document on how to tear down and rebuild a GM column. Doing the rack and sector and tightening the bolts is only the first part of the document. I printed it so I would always have it, and of course as I write this sitting at work, I cannot visualize where it is at home.

 

[DoubleDingo]

Since yours is a tilt column, tilt it down when starting, it'll start easier. I have this same project sans switch on my to-do list, and tilt the column down to start the truck. Once the engine is running, tilt the wheel back into driving position.

 

[DoubleDingo]

Found it. Was in my own thread...lol...

https://www.gmsquarebody.com/threads/steering-column-sector-gear-and-rack.28366/post-547088

 

[Terlingueno]

Found it. Was in my own thread...lol...

https://www.gmsquarebody.com/threads/steering-column-sector-gear-and-rack.28366/post-547088

I wonder if there is an equally thorough pdf on rebuilding a non-tilt column?

 

[DoubleDingo]

I wonder if there is an equally thorough pdf on rebuilding a non-tilt column?

Not sure. I'd suspect some info could be used and the rest not when rebuilding a non-tilt column? Without the tilt it should be a lot easier.