Ignition switch springing problem

[Steve W]

Well, here it is. Took the start switch/steering lock assembly out of the dash. Wasn't too bad. Removed the plastic key hole faceplace (unscrews off), and behind it you will find two shear bolts and two rivets. Removed the steering wheel for access, and drilled the shear bolts and rivets out. Under the dash, by the steering column is an allen set screw that need to be loosened also. Unplug the three harness plugs against the firewall behind the starter switch, unplug the plug from the starter switch, and pull the assembly out. Total time about 1/2 hour.

From there you will see the small pin around the key tumbler that holds it in. Drilled out the pin, only go about 1/8 to 3/16" in and not more than that or you will damage the key way. Wacked the keyhole face against a block of wood to release any residual of the pin and the key way cylinder should slide out. Just as expected, the backplate was loose, about 1/16", not allowing the thin steel plate sandwiched between to rotate as it should, putting the assembly on permanent starter lockout. There is no way any amount of lube or cleaning would have fixed this situation. You can see the thin steel plate in the first pic below. The cylinder was placed keyhole face down against a block of wood, and with a hammer and punch, the two retaining pins that are supposed to hold the backplate were repunched, fastening the backplate against the keyhole assembly just as when it was new. You can see the punched retaining pins in the second pic as the two black round dimples with the punch marks. This should be even more solid than when it was new, as the original retaining punch was kind of light.

The cylinder was put back into the assembly, and a small screw was screwed into where the retaining pin was drilled out. A hacksaw blade was used to cut off any protruding part of the screw so it was flush with the housing. Reinstall the assembly back behind the dash, and either use two 10mm bolts where the shear bolts were drilled out, or screw in two new shear bolts. Everything now works perfectly and just like new. Total cost about $0 vs. $500+ for a new assembly.

[pete3799]

Steve,
Good job!
Just did this last week, not a fan of the 500.00+ option either.
I didn't remove the steering wheel. If you use a prick punch on the sheer bolts they turn out fairly easily. For reassembly I dremmeled a slot in the sheer bolts and screwed them back in.

[Pazuzu]

Boy howdy did I learn something today! I always figured that little sprung plate on the back of the tumbler was just to keep tension on things. I can state that my lock set does not have a lockout action to it, even though it has that assembly on it. I wonder if they break two different ways, either always causing the lockout, or never causing it...

I'm also almost positive that my new electrical portion has a lockout inside of it. I wonder if the newer (964) mechanical assemblies have no lockout, leaving it to the electrical portion. I do not know what my old (stock) electrical part was like, because it came out of the dash in pieces

[pete3799]

Can't speak for anything newer than my 79 ignition, but the lock-out is in the tumbler on mine.
The spring under the pin on mine was broken and not allowing the pin to engage the lock-out.
I opted not to fix this and just left the pin out.
The reason for my disassembly was that my key would not turn.
The spring that returns the key from "start" to "on" is in the electical side.

[semo911]

Many thanks to you guys who responded to my question. I had time to replace the ignition switch today without being tired after work. Process went well and fix solved the problem.
Regards...Doug

[geardra]

My 71 911T is doing the intermittant loss of spring action thing. When I turn the key to the right the lights come on but there is no spring resistance and no starter. I replaced the electrical portion of the switch (lots of fun) but the problem continued. I havnt yet tried squirting WD or graphite into the keyhole yet. Reading the posts there appears to be some difference of opinion on the subject. Any words of wisdom out there?

[rwest]

Hi,

That two wire plug on the mech. part is for the annoying buzzer to remind you that you left the key in, mine was disconnected when I bought the car, so I reconnected it, and you guessed it, took it back off again!

Rutager

[Steve W]

It's not that your switch has a springing problem, it's that the starter interlock on the tumbler is preventing you from turning the key far enough to hit the starter/springing position. In other words, it's not the electrical switch, but the mechanical section.

[geardra]

I tried the WD 40 in the switch before trying to outspend the problem. Works perfect now. There are apparently several things in there that can act up and yet show the same symptom. Keeping my fingers crossed.

[80nick]

Bringing this old post back up hoping on I can get a little more clarifiction on how this ignition switch works.

I pulled mine apart after searching and reading several threads. The pressed on plate was completely off of the 2 pins. I have it at the locksmith getting re-keyed to match the doors and glovebox.

The question: If I leave the little pin, it's spring, and the thin ring out, I can put it back together and all will be fine except that I will not have the starter lockout feature, correct?

[DRACO A5OG]

sadly me too, I have intermittent no starts.

I hear the fuel pump, starter solenoid click but no start, after 5 minutes starts right up and for rest of the day.

just order electrical part but I may have to do Dr Wong's fix, oh the joy

but I still have good spring action. the reason I suspecting the electrical portion is after 1/2 a dozen tries my right turn signal quickly flashes, very wierd but I am guessing it could be some fault in the contacts on the electrical side.

[80nick]

It's not that bad once you have the shear bolts out. Lucky for me, I guess, the PO had replaced the ignition switch at some point and put in allen head bolts instead of the shear bolts, so now I can have the entire ignition(electrical & mechanical) out in about 10 minutes.

I would like to know if I can leave the pin and rotating plate out though?

[ficke]

Originally Posted by Steve W

Well, here it is. Took the start switch/steering lock assembly out of the dash. Wasn't too bad. Removed the plastic key hole faceplace (unscrews off), and behind it you will find two shear bolts and two rivets. Removed the steering wheel for access, and drilled the shear bolts and rivets out. Under the dash, by the steering column is an allen set screw that need to be loosened also. Unplug the three harness plugs against the firewall behind the starter switch, unplug the plug from the starter switch, and pull the assembly out. Total time about 1/2 hour.

From there you will see the small pin around the key tumbler that holds it in. Drilled out the pin, only go about 1/8 to 3/16" in and not more than that or you will damage the key way. Wacked the keyhole face against a block of wood to release any residual of the pin and the key way cylinder should slide out. Just as expected, the backplate was loose, about 1/16", not allowing the thin steel plate sandwiched between to rotate as it should, putting the assembly on permanent starter lockout. There is no way any amount of lube or cleaning would have fixed this situation. You can see the thin steel plate in the first pic below. The cylinder was placed keyhole face down against a block of wood, and with a hammer and punch, the two retaining pins that are supposed to hold the backplate were repunched, fastening the backplate against the keyhole assembly just as when it was new. You can see the punched retaining pins in the second pic as the two black round dimples with the punch marks. This should be even more solid than when it was new, as the original retaining punch was kind of light.

The cylinder was put back into the assembly, and a small screw was screwed into where the retaining pin was drilled out. A hacksaw blade was used to cut off any protruding part of the screw so it was flush with the housing. Reinstall the assembly back behind the dash, and either use two 10mm bolts where the shear bolts were drilled out, or screw in two new shear bolts. Everything now works perfectly and just like new. Total cost about $0 vs. $500+ for a new assembly.

This is awesome, you saved me a lot of money, thanks!
This is the best of what this sight is all about.

[SoCalSK8r]

I finally got around to pulling my ignition switch today and indeed the switch was stuck in permanent lock out mode. I was able to resolve that issue thanks to this thread.

Unfortunately that’s not enough to resolve the issue.
I know the electrical switch works using a screw driver, that’s how I’ve been starting my car for the last year b/c I didn’t have time to dive into pulling the mechanical switch.

Now that I’ve resolved the lock out issue, it seems I’m about 5 degrees short of the mechanical switch fully engaging the electrical switch.

Perhaps my electrical switch is worn to the point where the mechanical switch can’t rotate enough to engage it?
I have been using a screw driver to turn it over for the past year so perhaps I over stressed the spring assembly in the switch. Thoughts?

[poorshe911]

Lots of great info about the no start issue due to the ignition switch. I started to get ready for the key lock removal and thought I’d first try what Phrog did to resolve his issue by spraying some wd40 into the switch. The car now starts every time instead of 1 out of 15. Guess I got very lucky. See how long the lock lasts.