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MG Midget and Sprite Technical - Ignition switch stuck

I probably should have known it was coming. Beautiful day here in New England after too much rain and heat this summer. Tried to start my 1971 GAN5 Midget and the key rotated halfway and stopped. No amount of jiggling and penetrant can make it budge.

So I pulled the steering column this evening and I've got questions. Looks like the ignition switch assembly is not meant to be easily removed. I expected two screws holding the yoke together, but that's not the case.

I checked the archives and there are two important threads that should point me in the right direction.
The first said the problem is at the switch part on the left side of the column. I see two very small screws diametrically opposed that might be holding it in place. Will they let me in to the source of the problem?

The second thread mentioned a spring in the switch. When I recently had things apart to replace the wiper/washer switch, I found a spring just loose in the plastic cowl. I saved the spring, but couldn't figure out where it was meant to be. That's what I mean about knowing something would happen. Is the fugitive spring the source of my problem?

Tomorrow's supposed to be another great day here, and I'd sure like to get back on the road. I'd appreciate any advice.

Thank you.





Mark 1275

ETA: IIRC the previous spring was too big for anything to do with this.

Mark,
removing the screw(s) with the red arrow to it will allow you to remove the contacts part of the switch away from the switch - if you're really lucky this may be all that's needed to get the key to turn.

If not you will now be able to see the lug of the switch, this may allow you too get a tool on it so that with the key you have two points to try to turn the mechanism to move and release the key.

You want the battery disconnected before starting just in case and I can't remember if removing the contacts gives another point at which you could try to get releasing fluid in to the switch.

Note, standard WD40 is not a good penetrating fluid, something?Blaster or Kroil are better.

Let the (correct) chemicals do all of the hard work, soak and leave as long as possible to penetrate before trying to tighten or loosen anything.

Once the contact part is out you can clean and lubricate it with a switch cleaning lubricant like Super Servisol 10.

For the metal part of the lock you could make up your own graphite oil or go all modern and save the mess and hassle by buying something like Lock Saver.

Something I do for car keys and remote fobs is to alternate their use that way you get more even wear on the keys (batteries) and locks and you know they all work and where to locate them. Many modern cars are sold with just one key and the other is hidden somewhere like at the back of a former owner's kitchen drawer.

Good luck let us know how you get on.





Nigel Atkins

Great advice, Nigel! Worked just as you described. Removed the switch and it allowed me access to the lug/post, and between that and the key it's moving again.

It's still not working as smoothly as it should be, so I'm soaking from both ends with penetrant. The one I use is PB Blaster, but I'll look for U.S. equivalents to the two you mention. Feels like the problem is with the key and lock, rather than the switch.

After using penetrating oil, my plan is to clean it out with a spray solvent, then lubricate with a lock lubricant.

I'm curious, if I did want to replace the switch assembly, how the heck do you remove it? Are the pins on top meant to be tapped with a drift? Drilled out? Is there more disassembly? I see Moss sells the assembly, but I'm not sure how I'd get the old one off.

I'm lucky people like you spend time on forums like this to help people like me.


Mark 1275

I had the drivers door lock on my daily driver VW Passat suddenly go quite stiff which was rather concerning as it's the only key lock on the car other than the boot but got it open and home. I gave it a good dousing with Wurth HHS 2000 lubricant and that improved things so once it was somewhat better some further douses and some exercising of the lock it seems to be back to normal. Must go a do a bit of preventative lubrication on the house locks.
David Billington

Mark,
it'd still be worth cleaning the contact part of the switch, if possible with a spray that will clean and lubricate electric contacts in one go, lots of different sorts with do this, probably one or more in the WD-40 brand.

For cleaning the lock if you wanted to go further I think it might have been Guy that detailed dropping the ley barrel out to clean and reassemble in the Archives here, or someone in the other models sections, I'm sure I've seen it on this site.

Assuming (always dangerous) they're the same as over here, those pins are shear head bolts, so as they're screwed in at a certain point the head shears off as an anti-theft device for the car. You may need to look at them on the underside to the arrow. You can drill them out, obviously with care to avoid taking out the threads of the lock assembly if you expect/need to reuse it. 6mm or 6.5mm drill bit, I forgot which.

I do know I was glad I didn't shear the heads off the bolts until I'd taken a test drive as when I fitted a new lock the steering lock engage on three tests with the car parked up but on returning from the test drive I had to loosen the shear bolts and slightly realign the lock to column to get a smooth engagement and disengagement of the steering lock operation. I saw here that some leave the heads on and don't ever break them off.




Nigel Atkins

David,
I bought a very small bottle of graphite oil (less messy than making my own) and I used it on all the home door and window locks, on the Midget's locks, shed padlocks, my neighbour's front door lock and still would have had enough to last me decades if I hadn't lent it to my neighbour to do the rest of his locks and never seen it again. If you use it sparingly and carefully it's not messy, very effective and long lasting and very economical even at the cost of a small bottle and I've only had to use it once, years ago.
Nigel Atkins

Martin,
I picked Lock Saver as it's an USA company, Mil-Comm.

I'm a fan of GT85 which used to be a British company until WD-40 Company took it over (they also own 3-in-One). WD-40 company an invasive company in the same way as Coca-Cola company ("200+ countries and territories offer our products") and Mars, both these offer within their brands basically the same wide range of similar (same?) products under various brand names and with Mars Petcare particularly piss-poor products that reminds of many classic car parts quality.

I think Servisol Super 10 in now a CRC product but I don't know if they only market it in Europe.
Nigel Atkins

David,
sorry I've just thought, I used graphite powder not oil, a very small bottle of it about £3 or £4 pound at the time, which I applied to the keys and then to locks with key half in to open up to barrels.
Nigel Atkins

I did replace the unit, and the Moss replacement works fine.

But I'm very curious what went wrong with the old assembly, and I'd sure like to find a way to take it apart to see what's inside. If there's a thread on this somewhere, please let me know. Couldn't find it here or in the MGB archive, but it might be my search technique.

I removed the two threaded studs by cutting slots in their tops with a Dremel cut-off wheel and then used a screwdriver. They came out very easily.
Mark 1275

Which unit did you replace?

Did you recycle (reuse) the threaded studs.

Have you had a look on Paul Hunt's site to see what's there on the subject. - http://www.mgb-stuff.org.uk/hammertext.htm

Or the MGB Archives.
Nigel Atkins

Helpful site! It looks like a later version of the key lock, but it will help me figure out how to get in to mine.

The Moss unit is the whole assembly, including keys, electrical switch and yoke. The wiring harness was a bit shorter than what came out, but overall it's a drop in replacement. It's wicked hard to get the key into the cylinder, but I assume that will wear in with use.

I didn't reuse the old studs. Used the new ones and IIRC didn't break off the heads.

Glad to be back on the road. Thank you.
Mark 1275

Yes Paul's site is very useful.

Sorry I meant to put have a look in the MGA (and Midget & Sprite) Archives, not B Archives where you've already looked, as I'm sure something on the lock tumblers has been covered before.

If you have any, spray the new and existing wiring sockets with electrical contact cleaner.

For the new keys check for sharp edges on them and if they are any rub them off with a small fine file if you have one, brush or wipe off the key blades as you don't want any debris going into the lock. Then rub the graphite tip of a pencil over the blades of the keys and keep working them in and out of the lock.

Two new keys and lock is the perfect time to start alternating the use of the two keys to get even wear and to remember where the spare keep is kept and that it works well in the lock. I change over at 6-month services but you might have a better system.

Well done on sorting it, do road test and then a check those bolts are secure and that's an end to it.
Nigel Atkins

This thread was discussed between 04/09/2021 and 17/09/2021

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