C3 Spare Tire Lock...Help!

[Peter G.]

Went today to change out my spare tire and the spare tire lock won't unlock!! In fact the key won't even go into the lock all the way?

What a surprise. I just had the spare tire out for the Rocky Mountain Regional back in May with no trouble?

How do I get this lock off? And the spare tire out of course.

Any suggestions or past experiences.

Thanks

[Jim T.]

Re: C3 Spare Tire Lock...Help!

Peter this is nothing you cannot take care of and easily. Look up from the spare tire lock and you will see two bolts (9/16 head I think). Remove these two bolts and you will have the bracket and the long bolt with the lock on the end in your hand. Now you can take this assembly to your work bench and put some graphite or light oil if you perfer and see if you can work your key in. Great time to lubricate the bolt threads as well.
I have not had the spare tire locks on my 68 and 70 for years, just keep them inside the car even though the cars have been garaged for past 17 years and not driven daily.

[Peter G.]

Re: C3 Spare Tire Lock...Help!

Thanks Jim. I had forgotten about that bracket with the two bolts up on top. It's pretty dark up there especially laying on your back trying to unlock the lock.

I guess I just paniced! There is a Corvette Show coming up this Saturday and I was starting to get a bit concerned.

What is that small hole next to the key opening? I thought it might slide the key core out if you insert a paperclip?

[Jack H.]

Re: C3 Spare Tire Lock...Help!

Starting in 1967, GM/Briggs changed keys and locks to increase the number of physical permutations. This was done by adding a 5th wafer/tumbler to the existing four that were available AND by keyway encoding the lock to the key.

The keys were stamped on the side (A,B,C,D....Etc.) representing their specific keyway codes. On Shark cars, the 'acid' test during judging to determine whether a given key/lock is correct/original or if it has been changed, is to know what the original keyway codes were that year and to attempt to insert another key with a different keyway code into the lock. If the lock is properly keyway coded, it'll reject the 'foreign' key meaning it won't insert more than 2/3rds of the way into the lock.

When you say your key wouldn't even insert into the spare tire lock, it might be this issue you're fighting. The spare tire lock should be coded to match the rear storage compartment lock. And, if memory serves, you've got a 1973 Corvette where the door/ignition locks should have 'E' coded keyways while the glove box and spare tire locks should be 'H' coded...

[Dick W.]

Re: C3 Spare Tire Lock...Help!

Sounds like a little penetrating oil would cure your problem. Since your key worked a few weeks ago the tumblers must have frozen up.

[Peter G.]

Re: C3 Spare Tire Lock...Help!

Yes, thanks everyone. After Saturday I will unbolt the top bracket and get everything onto the workbench and do a complete check and lubrication of the bolts and lock.

Then will probably like Jim says just put it back into the glove box behind the passenger seat until judging next time. The car is usually never out of my sightand alwasys in the garage.

One question though, I have to ask: Jack... what is "permutations"?

Thanks

[Jack H.]

Re: C3 Spare Tire Lock...Help!

When in doubt, there's this 'thingy' called a dictionary, Peter. But, to save you time, permutation is a mathematical term from the area of statistics. It's similar to the concept of combination but there is a subtile definitional difference between combinations and permutations...

[Dick W.]

Re: C3 Spare Tire Lock...Help!

Peter, electrical engineers tend to have their own vocabulary and live in their own little world!

[Chuck S.]

Re: C3 Spare Tire Lock...Help!

Sounds like a little penetrating oil would cure your problem. Since your key worked a few weeks ago the tumblers must have frozen up.

Great minds think alike!

Uh...Or, maybe it's because we're both too old or lazy to mess with taking that bracket off. Using WD40 to give a lock cylinder a good flushing is probably not good practice, but it's always worked for me. The tumblers get dry and bind up in the bores; a little lubrication fixes the problem.

[John H.]

Re: C3 Spare Tire Lock...Help!

One question though, I have to ask: Jack... what is "permutations"?

Thanks

We used that term a lot in the assembly business when we were fighting "parts proliferation" - it describes the total possible number of combinations of different parts as end products when all the different ways of combining them is considered. As an example, when DeLorean arrived at Chevrolet in 1969 and saw all the different/separate un-packaged options that a customer could order on a Camaro, he wanted to know the number of build combinations the "open" option structure could generate, and what it meant to total part count and usage forecasting for procurement. It turned out that there were over 300,000 possible "permutations" - we could theoretically build over 300,000 1969 Camaros and never build the same one twice. That's when option "packaging" started in earnest.

[Terry M.]

Re: C3 Spare Tire Lock...Help!

So I can blame "good ol' John Z" for my frustration when I ordered the 2008. That experience was nothing like ordering my 1965 Impala in SO many ways.

[Dick W.]

Re: C3 Spare Tire Lock...Help!

Chuck, I have freed up several locks by soaking in Stoddard solvent, when we could still get the good parts washing solvent. Mineral spirits is also good to soak them in.

[Jack H.]

Re: C3 Spare Tire Lock...Help!

Yes, and the wide world of electrons is essentially invisible. So, heh, heh, heh, watch your back, Dickie!!!