How lucky are you feelin'?

For careless tankers, pure luck is the only difference between a main gun elevation lock that works and one that creates an unsafe tank.

Careless tankers don't pin the lock to the gun mount assembly bracket after releasing the cannon from the stowed position.

If you're lucky, the lock will fall forward out of the way. As luck would have it, though, it often falls back against the breech ring when the main gun is fired. As the main gun moves back into battery, the breach ring hits the travel lock and shears the mounting bracket from the main gun cradle.

When that happens, safety is jeopardized for both the crew and mechanics. Several maintenance functions rely on this lock to keep crewmen and mechanics out of harm's way.

That little slip up will cost you a lot of down time since a depot-certified welder will have to come to the tank to make repairs. But even worse, your unit has to fork over $30,000 for a new main gun cradle.

Mechanics, you can install a very low cost insurance policy by adding a spring to the lock. The spring forces the lock to the stowed position, keeping it away from the breech ring.

When you're finished, make sure the chain attached to the lock's quick-release pin is short enough to keep the pin from getting caught under the lock. Remove a few links if necessary.

Here's how to put the parts together:

1. Remove the old cotter pin and straight-headed pin.

2. Place the new spring over the elevation lock.

3. Slip a washer over the new pin and slide the pin through the spring and lock.

4. Place another washer over the open end of the pin.

5. Secure the pin in place with the new cotter pin.

Here are the parts you'll need:

  Size                NSN

Spring         5360-01-384-5338
Washer         5310-01-384-4231
Pin            5315-01-385-7871
Cotter pin     5315-01-378-7858