We could have done a weenie step-by-step install of the OX Trax Locker from Superior Axle & Gear in the front Dana 44 axle of our Ford F-150. We could have shown you a regurgitated instruction sheet, but we had a better idea. It didn't involve guns (although we thought about shooting at the OX billet diff cover), but instead a long-term torture test. We cranked on down to Drivetrain Direct in Corona, California, and had an OX Locker stuffed into our fullsize test pig. What better way to try and break something than with a healthy V-8, 37-inch-tall tires, and plenty of fullsize weight?
Unless you've only recently come out of a coma you've probably heard of the cable-controlled OX Locker. It acts like a conventional open differential when unlocked, but with the flip of the small shifter you get spool-like traction and performance. There are no air lines to get damaged or solenoids on the diff cover to get crushed, only a large industrial cable that threads into the side of the 1/2-inch-thick machined diff cover. Almost every component in the locker is made from solid machined billet steel and is hogged out with CNC machines--no cast, no pot metal, and no cheese. Here's a couple of install ideas and what we found out during our six-month bout.
Drivetrain Direct in Corona, California, yanked out the old open carrier in our Dana 44 front axle and filled the void with the OX Locker. The cable adjustment is a little tricky but not difficult if you read the instructions. The factory carrier only has two differential gears; the OX has four. So even when the locker is disengaged the carrier is still stronger than stock. | 
Vehicles with long-travel suspensions will have more difficulty running the cable because you'll need more slack to compensate for extreme droop. We ran ours along the upper suspension link and into the cab from underneath. Several different length cables are available for front and rearend applications, so plan cable routing before ordering parts. | 
The OX diff cover is machined out of billet steel and is more than 1/2 inch thick in most areas. You certainly aren't going to dent it. In a frontend application the tie rod will protect the cable unless you're running high-clearance steering. The cover features a smooth bottom and a countersunk drain bolt for easy service. |
Our only complaint was with the old-style shifting mechanism. It wouldn't go right in when we wanted it to. We needed to pull the vehicle forward or backward slowly with the steering wheel turned slightly to get the locker to engage. This allowed differentiation in the locker so the teeth would line up for proper engagement. | 
By the time you read this, all OX lockers will come with this new shifter that we managed to get our hands on by the end of our testing. It's spring-loaded and engages seamlessly without any hassle. It's also easier to install and adjust. We mounted ours off of the interior rollcage and next to our tranny shifter so we could get to it easily. | 
What Broke
To try and torture our OX we put our Atlas transfer case into front-wheel drive, locked the OX, engaged the emergency brake, put it in gear, and violently spun the front tires in loose soil while steering back and forth. The result was a spit-out 297 U-joint cap. We pounded it back in and installed a new clip and went for a short vertical climb with substantial throttle. It popped the cap out again because the shaft ear had been hogged out and the cap had spun again. But no locker problems. If you plan to really abuse your Dana 44 you'll probably want to upgrade to full circle clips and chrome-moly shafts. |
More Than Rocks
A selectable front and even rear locker is big help for rockcrawlers trying to make sharp turns on the trail. With the lockers unlocked the vehicle will actually turn instead of pushing into a corner. But not everyone is into hard-core rockcrawling--shoot, less than half the country even has rocks in it.
Our F-150 was built for just about anything we can throw at it. But mostly high-speed stuff, hillclimbs, jumping, and sand dunes. If you have a similar rig that sees many kinds of 'wheeling, then you'll want a selectable front locker, hands down. Chances are you don't need it all the time. A full-time locker can cause some quirks at high speeds when in four-wheel drive or even in two-by with the hubs locked. Understeer can be a problem when sliding around a corner off-road. With the OX we can disengage the front locker and still bash around in four-wheel drive with little steering difficulty. But when we get stuck or want to climb we can lock it and hammer down.
If you have a vehicle with an axle disconnect system (some Jeeps and Dodges) or without locking hubs, a selectable locker is really the best way to go. Your vehicle will drive just like factory when disengaged. Non-selectable lockers and even limited slips will cause some torque steer when driving on the street in two-by.