A review of the last grease coupler you’ll ever need, the LockNLube

Several years ago, I was standing in a field watching a friend of mine add grease to a wheel. When he was done, he tugged on the coupler, and it held fast to his wheel. He tugged a little harder, and the coupler ripped the zerk right out of its threads, necessitating a repair before grease could be added to the hub.

Sadly, I’ve done the same thing before myself when greasing things, which I’m a little fanatical about. As I got older and wiser, I learned to take the coupler off at an angle. I slowed down and would unscrew recalcitrant couplers to coax them off fittings, but you know what? That takes forever.

I am ashamed to say I came across this product on a late-night infomercial after stumbling in from a night of partying. The late night antics were common for me at the time, but purchasing things from infomercials was a bit out of character. (I did at one point keep a very well-used Pocket Fisherman behind the seat of my old Chevy and maintain it was an excellent product, even if it was larger than nearly any pocket.)

In theory, it seemed perfect. Rather than relying on achieving the perfect tension by way of the coupler’s threads, the LockNLube promised to snap onto a zerk fitting and then release all tension by way of a thumb-actuated lever. It looked so easy, just like it always does in the infomercials. So I dug out my credit card and I bought one.

I’ve been using it now for at least 6 or 7 years, and my opinion of it is as high now as it was the day I received it.

I haven’t so much as marred a fitting since I screwed this on the end of my gun. The hardened jaws go on and off like they’re supposed to, and because of that spring-loaded lock, you can clip it on and run the grease gun with two hands.

I still keep a standard coupler on an old gun I have, but I hardly ever use it. For antiques, off-road equipment, farm stuff, and trailers, this coupler is the one to have if you ask me. The thing never pops out and makes a mess, and I never damage fittings (or the item they sit in) any longer. I even have a few drive-in style grease fittings that make me wince when I used to use a “normal” coupler on them, but with this LockNLube coupler, there’s no chance of damaging even those.

Photo: Lemmy.

They’re rebuildable, though you pay for rebuild kits. I think mine was cheaper than they go for now, which at the time of this writing seems to be between $30 and $35 depending on where you get it and if it’s on sale. This thing is larger than a conventional coupler, so there are times when it’s a squeeze to get it in somewhere, but that’s somewhat mitigated by their “XL” version, a coupler that costs a few bucks more and has an extended snout.

It’s rare I come across a fitting where this doesn’t work, but it does happen. Still, I feel that’s a very small price to pay for the convenience of quickly greasing ports with almost no concern about one ripping out. Especially on ag equipment where there may be dozens of fittings to access during a service, this little sweetie saves me time and broken parts. I cannot recommend this upgrade highly enough.