Making CV Joints Live

For applications that don't use RCV's custom seal, you can still improve the effectiveness and life of a rubber CV boot with an over boot. Factory boots fail for a variety of reasons, but primarily, they are easily torn by trail debris - even flying gravel and rocks can damage the boot. The over boot is made from either nylon or leather, and it installs over the rubber boot. It can take much more abuse from debris, and allows the rubber boot to do work as what it was really designed as - a seal.

This is the solution for lifted GM IFS 1500, 2500 and 3500 trucks. RCV replaces the plunging in-board CV joint with a fixed CV, providing up to 40 degrees of joint articulation compared to only 15 to 20 degrees with the stock joint. This is the cause of much of the vibration IFS trucks experience after a really tall suspension lift is installed, and leads to failure of the factory shaft assemblies.

The slipping action is now provided by a splined center shaft, similar to what you would find in a driveshaft, with about 2.75 inches of travel. The slip joint includes a grease fitting. This assembly also eliminates the spacer supplied with some lift kits, further improving the operating angle. The spacers allow the axle flange to connect to the center section, but they actually make the angle worse - which the stock assembly can't keep up for long.

A lot of the off-road racers who want long-travel IFS, but need parts to last longer than one race, are adapting a Dana 60 center section to RCV Pro 4 Super in-board CV Joints and RCV D60 outer joints. The splined axle flange attaches to the inboard joint to provide up to 40 degrees of movement with Dana 60 strength.

These photos show the range of motion that the Pro 4 Super in-board CV joints are capable of......

.....In addition to up to 40 degrees of angular movement, they can also plunge in and out, for up to 1.75 inches of travel.

RCV Performance is also known for their custom axleshafts. They can make shafts for any application from a variety of high-strength aircraft-quality material. They can do solid axles as well as gun drilled, and offer a choice of coatings. Most of their axle shafts are guaranteed against breakage.

Among other test equipment, RCV Performance built this torsional strength test fixture. It allows them to apply up to 50,000 pounds of twisting force to an axle assembly with either a U-joint or a CV joint at angles up to 45 degrees. While this doesn't replicate shock loads, it does give the company an indication of what part will fail first (and how) so they can engineer a better solution.

Going Straight, Axle That Is
It may be an uphill battle, but RCV Performance believes in the advantages of CV joints so much that they have developed kits to convert a solid axle to use CV joints in place of U-joints. The advantages are CV joints that are both stronger than the comparable U-joints and they eliminate crow hop, or binding as you make tight turns in four-wheel drive. They also operate in a greater range of angles. The kits also include chromoly inner and outer axleshafts, which are far stronger than factory shafts, and RCV's patented dust seal and everything you'll need to do the swap.At this time, off-the-shelf kits are available for Jeep Wranglers (TJs and JKs) with Dana 44 front axles. RCV also makes a kit for Dana 60 applications with custom-length axleshafts. It might take quite a bit of time to get hardcore straight-axle guys to try a CV joint in place of their U-joints, but it may be a turn for the better.