Tech Briefing:

Ox U-Joints

story and photos by Jim Allen

Spicer builds what are considered to be the best OEM style U-joints. Several of this greaseable Spicer 297x unit’s brothers were destructively tested by an independent source and withstood just under 4,600 lbs ft. The new cold forged were even stronger at about 5,400. The Ox joints have been tested in the same way and could handle up to 22,000 lbs ft. The full circle clips are in the foreground.

The front axle shafts and U-joints on a hard working 4x4 live a hard life, especially when big tires and low gears are added to the equation. The past few years have brought a lot of technology to bear on this problem. The “old standby” has been swapping in a bigger axle, but that’s not always the ideal solution. A bigger axle is heavier and offers decreased ground clearance, not to mention being a difficult or expensive swap in many cases.

For many ‘wheelers, a few well-chosen mods to the existing axle will be enough to make them essentially bulletproof. To that end, the aftermarket has stepped in to cover the major weak links with alloy front axle shafts and superstrength U-joints. These mods address the strength issues of 90 percent of the ‘wheelers out there.

Ox Brand has developed a high tech U-joint that we will highlight here. It’s not a brand new product, but still only a year or so old. Ox Brand is the originator of the Ox Locker, a cable operated mechanical locker renowned for it’s simplicity and celebrated for its raw beef.

The Ox Joint definitely has a space-age look to it. Small wonder, considering the engineers that developed it have aerospace backgrounds. The Ox takes a different tack than the other super joints on the market, using a multipiece design best understood by looking at the accompanying photos. The others use a fairly conventional design patterned after the original Spicer, but substituting a chrome-moly alloy cross for the standard one, and replacing the caps and needle bearings with bushed caps.

Because the Ox (and the other super joints) has eliminated needle bearings (part of the secret to their strength), they are not ideal for continuous duty... such as with full-time four-wheel drive. Ox, however, is working on a design that will use needle bearings and be suitable for continuous duty, but it will be some 15 percent weaker. It may be available by the time you read this.

The Ox uses a multi-piece design, with a center body made of an 8620 alloy that has had some special and proprietary heat treatment. Instead of caps, the Ox has pins that insert through the axle yoke ear into the body and are retained inside a cavity in the body by a pair of 4340 alloy retainers. The pins are also 8620, but they get a different heat treatment than the body. The pins use an o-ring seal to keep water out.

1) Body 2) Body Cap 3) Pin 4) Retainer 5) Zerk fitting

So how strong is the Ox? The manufacturer has done destructive testing and found the unit can handle up to 22,000 lbs-ft. The new 760x cold forged Spicer is good for about 5,400 lbs-ft. The old 297s joint was good for about 4,600 lbs-ft. Ox claims their U-joint is nearly twice as strong as the next strongest super U-joint in the same sort of destructive tests. The Ox is so sturdy that it actually helps hold the axle yokes together longer under a heavy strain as well.

As to applications, Ox currently offers units that will replace the 297/760 Spicer sizes, which covers Dana 44s, GM 10-bolts, some Dana 30s and Dana 35 IFS, among a few others. A 332x size, to suit the Dana 60 front, is almost done and may well be available by the time you read this. A 260x series (many Dana 30s) and possibly even a 178x series (Dana 50 and others) are also on the to-do list.

A key element to keep in mind with regards to any super joint installation is that you must combine them with high alloy, beefy front shafts. Standard shafts won’t last because they are no stronger than the OE U-joint and sometimes even weaker. The average Dana 44 outer shaft is good for about 4,000 lbs-ft. The necked down section of many inner shafts is usually only good for about 3,700 lbs-ft. High alloy shafts (usually 4340) are available from a variety of sources and we were interested to hear that Ox will soon be among them. Stay tuned. In some cases, installing a super joint may void the warranty on the alloy axles, so be sure to address that issue in your mind beforehand. Ox joints are available through 4 Wheel Parts. s

Source: Ox Products • 866-652-0414 • www.oxbrand.com