Vintage Mac Toolbox Lock Tension

[centerknurk]

Working on restoring a Mac MB 5200 K2 toolbox from the 80's. The locking mechanism consists of a lock cylinder that spins a rod with a little kickstand on it that lifts up two locking rails in the back of the box. To lock the box, you spin the key to drop the rails down. Each rail has claws that cling on to the box drawers, creating the lock effect.

I noticed when I bought the box the whole mechanism seemed kind stiff when you turn the key. I replaced both springs that keep tension on the box with new springs I ordered from mcmaster carr, as one of the original springs was broken. However, things still feel "sticky" and stiff. It definitely locks and unlocks, but feel like I'm kinda forcing it.

Anyone have one of these boxes? How "stiff" is the lock mechanism?

 

[RTM]

The springs may not be your problem. Does it still bind if the drawers are all out? When dicking with a different toolbox, I moved the vertical locking bars separately from the key driven twisting bar piece, and had a bit of binding in each piece. Because people often close drawers into the locker chest, the vertical bars can be bent, swaybacked, etc. the twisting bar attached to the key could be fouled, needing derust or lube at either end. Get all the components working solo first, then go for the complete assembly.

If hard to lock when closed, on my NB box, the hooks on the drawer backs were bent, and the claws could not get over them easily.

 

[centerknurk]

The springs may not be your problem. Does it still bind if the drawers are all out? When dicking with a different toolbox, I moved the vertical locking bars separately from the key driven twisting bar piece, and had a bit of binding in each piece. Because people often close drawers into the locker chest, the vertical bars can be bent, swaybacked, etc. the twisting bar attached to the key could be fouled, needing derust or lube at either end. Get all the components working solo first, then go for the complete assembly.

If hard to lock when closed, on my NB box, the hooks on the drawer backs were bent, and the claws could not get over them easily.

Thanks for reply. It seems like the lock bars have a hard time moving whether locking or unlocking. I get that the key twist is moving up 2 metal bars, but it still feels too stiff. I wish there was a way to take the bars out somehow.