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How J.E. Reel Drive Line Specialists Build Driveshafts for Our TJ Wrangler Project

These are some must-know tips and tricks when selecting new driveshafts for your off-road 4x4.

Every 4x4 needs them, but most guys don't put much thought into them. Until they snap and leave you in two-wheel-peel out in the middle of nowhere. Taking the time to understand a few driveshaft fundamentals has a lot of benefits for the beginner to advanced off-road junkie. From survivability in gnarly terrain, to the ability to cope with big power and monster tires, to offering a buzz-free ride on the freeway, choosing the right driveshaft components, materials, and builder can pay big dividends.

So, when it came time for us to have a pair of drive shafts built for one of our 4x4s, we headed over to J.E. Reel Drive Line Specialists in Pomona, California, with a camera in one hand and a notepad in the other. J.E. Reel has been building driveshafts and drivetrain components at the same location for over 80 years. So believe us when we tell you J.E. Reel is one of the driveshaft building companies that have set the standard for others to follow. Here's how the company built us a pair of driveshafts for our TJ Wrangler in an afternoon and some things you should consider when selecting a driveshaft for your project.

Axle and Transfer Case U-Joint Sizes

There are a ton of yokes available out there from the funky Ford-only 1330-sized to the minuscule Toyota varieties, but the most common are (right to left) the Spicer 1310, 1330, 1350, and 1410. The 1310 is the standard U-joint size for the majority of - and -ton pickups, sport utility vehicles, and Jeeps. The 1330 shares the same cup size as the 1310, but it has a larger cross for more angularity and a little bump in strength. The 1350 is a 1-ton joint with a heavy, thick cross and fat caps, but it can't run at angles as steep as a 1330. The 1410 is a monster, with 1350-size caps and a larger cross for angularity and big strength.

Driveshaft U-Joints Types

Not all U-joints are created alike. These 1310 U-joints shown counter-clockwise from the top are a Neapco greasable, a Spicer greasable, a Spicer non-greasable, and a J.E. Reel H2O joint. The H2O joint features a cryogenically treated, high-strength alloy steel body that's 40 percent stronger than a regular 1310. The H2O joint also comes loaded with high-pressure, high-temperature, waterproof grease. Reel recommends running a greasable joint in lieu of a sealed joint so you can make sure the joint is loaded with fresh grease. Simply fill through the zerk fitting until all four seals purge grease.

Axle and Transfer Case Yoke and Flange Types

You'll also need to know or pick your yoke/flange type. CV flanges are disc-shaped squared off, and there's little chance of mistaking them for something else. However, shown here are three 1310-series yokes. From left to right, there's a CV yoke that accepts bolts through the back side, a strap type, and a U-bolt type. This type of CV yoke is most commonly found in vehicles with a slip yoke conversion, Jeep Wrangler and Cherokee front driveshafts, or even older Broncos. The strap type can be drilled out to accept a U-bolt, but it's easy to mess up and weaken the ears. Most driveline shops sell new Spicer and aftermarket U-joint yokes, which we prefer.

What's Inside a Double Cardan "CV" Driveshaft Joint

Here's an exploded view of a double cardan joint, often erroneously referred to as a CV, or constant velocity joint since it employs U-joints and not true constant velocity joints. However, for the sake of simplicity we'll refer to it in its 4x4 vernacular as a CV. We ordered a pair of J.E. Reel's Canyon Crawler series driveshafts equipped with 1310 U-joints and 1310 CVs. Technician Scott Thurn began by assembling our CVs.

How a J.E. Reel Driveshaft Is Built

Start to finish, once we determined we wanted our front and rear driveshafts to be a double-cardan type with 1310 U-joints throughout and of suitable strength for real rockcrawling, the team at J.E. Reel got to work. After filling the bearing caps with high-quality Lucas brand Red "N" Tacky grease, they pressed the U-joints into the CV shells.

Have you ever replaced a U-joint and found it hard to swivel in its cups? J.E. Reel showed us this little trick. Give the cup shoulder a teeny whack with a steel hammer. It'll be enough to settle the needle bearings and grease and allow free movement of the joint.

To determine how much tubing to cut for our driveshaft based on our yoke-to-yoke measurements in the vehicle, Reel first inserted the splined shaft into the slip joint. Reel uses 1-3/8-diameter spline shaft versus the normal 1-1/4-inch diameter found in some factory shafts.

At least 2- inch of spline must remain in the slip yoke at all times to prevent the shaft from wobbling or pulling apart. Thurn factors in this length as well as the length of the slip yoke and CV assembly to determine how much tubing to cut for the shaft.

For its Canyon Crawler series of shafts, Reel offers 0.120-, 0.188-, and 0.250-wall tubing. The 0.120-wall is plenty strong, but the 0.188-wall is significantly stronger without a huge penalty in weight or balancing issues. The 0.250-wall tubing is pretty bombproof, but its weight can lead to difficulty in balancing the shaft and, honestly, is just overkill unless you're doing insane rockcrawling all the time. We went with the 0.188-wall tubing for both our shafts.

Since the slip splines Reel uses are designed for 0.120-wall tubing, the splines must be machined down on a lathe for a light press fit. The tubing ends are also taken to the lathe so a chamfer can be added to the ends. This ensures maximum weld penetration between the two parts.

It's only a matter of minutes, but it's a step some driveline shops may not stop to take. There are only a handful of driveshaft shops in the country that we trust to build stuff for our project vehicles. J.E. Reel is definitely one of them.

Reel uses very high-quality Lucas Red N Tacky grease to lube the driveshaft splines before assembly. This helps ensure the components don't wear and get clunky as the suspension cycles and the splined end travels in and out of the driveshaft.

With the components machined, the shaft can now be assembled. Care must be taken to ensure the yokes are in phase or the shaft will be impossible to balance. The shaft is clamped in a vise, and a precision level is used to insert the yoke CV end in phase with the U-joint on the slip spline end.

Once assembled with the joints in phase, the shaft is transferred to the balancing machine where it's bolted up. The shaft is first checked for runout to make sure the tubing, slip splines, and CV end have all been assembled squarely. Otherwise the shaft will look like a wet noodle when it's spinning and will vibrate your fillings out.

Once the runout is verified to be within spec, the parts are tack-welded and runout is checked once again. Finally, once satisfied, the shaft is slowly spun on the machine as the welder nozzle is held in place by a fixture to ensure a constant and straight weld bead.

To prevent burning the grease or melting the seals, the shaft is quickly doused to cool down the steel.

Once cooled, the shaft is spun at simulated freeway speeds to determine where the balance weight(s) need to be installed.

The weight is first taped in place with several wraps of masking tape and the shaft is spun again to ensure the weight position is correct. Once verified, the weight is burned in place, ensuring a vibration-free shaft for years to come.

While our front shaft was being built, we laid our rear shaft next to a customer's Long Travel Driveline. Reel will build its Long Travel Driveline with just about any combination of yoke or CV required and can accommodate 24 inches of travel. And unlike some tractor-spline shafts, the Reel Long Travel Driveline can be used in a rear applications.