Caterpillar Inc. is well known for their earth-moving equipment, and some of the machines they make are massive! Their products can literally change terra firma in ways we never knew possible not long ago.

So when Caterpillar contacted Stage 8 Locking Fasteners with a problem, we knew it was serious. They were having issues with their differentials and transfer shafts. Most differentials (like the ones in our everyday cars) mainly drive in one direction, forward.

But moving earth requires the machine to go back and forth quite a bit. All this back and forth was causing the large nut securing the pinion gear to come loose. This in turn would cause incorrect gear meshing and finally gear failure. The repairs were costing Caterpillar dearly in both parts and labor — not to mention the down time nobody likes.

Stage 8 tackled the problem with its Patented Locking Spindle Nut Assembly. Known as the “X-Lock,” this product was the perfect solution for Cat’s problem. It locks the nut wherever it stops, ensuring the torque value stays exactly where you put it.

Now this wasn’t a simple matter of “here you go, try this” — Caterpillar doesn’t work that way. Stage 8 was in competition with several other companies to prove the X-Lock was the best solution to eliminate the problem. After several tests of various types, it came down to a reverse torque test, to either fail or loosen.

Testing completed, Caterpillar brought all the companies into a meeting room to discuss the findings. There in front of the room was a large white board with all the companies listed including Stage 8. Listed under each company was the torque value it took for each product to either fail or come loose. The values were impressive, the other products were averaging about 150 – 170 Ft Lbs. Listed under Stage 8’s name was 650 Ft Lbs with a big ol’ “?”

That’s right — a question mark.

So we ask, “Okay what’s up with the question mark?” Well that’s as high as our torque wrench went, so we don’t actually know how much torque it takes to fail your product.” That’s what we’d call a pretty good endorsement!

Once prototyping was done and fitment dialed in, it was off to production for the X-Lock. To this day Caterpillar still uses the Stage 8 X-Lock on many of its machines.

The X-Lock Story Continues

Soon after the X-Lock went into production for Caterpillar, a long time friend of Stage 8’s President Bruce Bennett came by to visit.

“Hey Tommy [Tom Scahill], look at our new Caterpillar product, it’s a Locking Spindle Nut!”

To which Tom replied, “Locking Spindle Nut, huh? That might work on my Baja Truck.” Turns out Tom races the Baja 1000 every year in a four wheel drive Chevy truck. “Every year I have to pull over every 200 – 300 miles to re-tighten the spindle nuts on my front wheels.”

One thing lead to another and before long Tom had two downsized X-Locks for his Dana 44 front differential. He ran Baja that year as usual and came back beaming. “Yeah I pulled over like I always do but those X-Locks were fine every time, I didn’t need to touch them the whole race.” Oh by the way — Tom won that race.

Stage 8 now makes the X-Lock for many popular four wheel drive front axles like the Dana 44, Dana 60 as well as the first generation HUM VEE.