spare tire lock 70-72

[lyndon sharpton]

are all the repo locks the same? do they all use the same key?

[Joe L.]

Re: spare tire lock 70-72

lyndon----

I believe that all of the locks on the market are either the GM SERVICE lock GM #3912416 or the same lock as otherwise obtained from the manufacturer. The 3912416 lock is supplied with a key which is the round style key used from 1968 onwards. It can be re-coded to work with your existing round key. They are not supplied, though, with a key code which is the same for all SERVICE locks. I don't know how many codes there are, but there are certainly more than 1.

[Jack H.]

As Joe says...

spare tire locks from different sources will vary in their configuration. Starting in 1967, GM added a 5th wafer/tumbler to the coding sequence to increase the number of lock permutations AND they initiated keyway encoding to further increase the number of lock permutations. A '70-72 Corvette shipped from the factory with its spare tire lock keyed to agree with the rear storage compartment lock.

This means the spare tire lock for a '70 Corvette differed from a '71 as well as from a '72. Specifically, a '70 Corvette spare tire lock had a 'K' keyway encoding, a '71 Corvette was 'B' coded and a '72 Corvette came with a 'D' keyway coding. The letters I'm using to describe the lock's keyway coding format matches the small letters you see stamped on the side of your car keys.

The functional test is for each lock to accept the insertion of it's mating coded key and 'reject' all other keys (can't insert them more than 2/3rds of the way into the lock). Locks that fail to match the appropriate key used in a specific year lose originality points during Flight Judging and constitute an automatic failure in a Performance Verification test.

Some locks have universal keyway encoding, meaning they'll accept any/all keys (make life easy in service and reduce the number of parts you have to carry in inventory). These will also 'flunk' an NCRS inspection....

So, while many catalog houses list spare tire locks, what you get is generally the result of random pull from their inventory. If you want the spare tire lock to be factory concours correct for your car, you have to specify the year & keyway encoding you need at the time you order.

Some catalog houses will then hang up on you (hey, a lock's a lock!), while other suppliers may be more enlightened and offer to sort their inventory (might ask you for a sorting fee) to see if they can supply the correct lock to match your car...