How to Replace Your Car's Halfshaft

Most cars sold in the United States drive the front tires. It makes for inexpensive, easy-to-manufacture, roomy cars that get better gas mileage than the rear-wheel-drive alternative. Getting power from the transmission to the front wheels is a bit of a challenge though. That's what a halfshaft does. The two halfshafts have the simple job of transmitting torque to each of the front wheels. But that job is complicated by the drastic up-and-down motion of those wheels, the near-90-degree difference in lock-to-lock steering angle, and the requirement to attach to a stationary transmission.

In spite of this the halfshaft is a robust part with a reliable 100,000-mile life span. Still, like every stressed part, it eventually fails. The rubber boot on the wheel side is usually the culprit. It's easy to diagnose. If your car drives fine in a straight line but you hear a ticking noise from the outside wheel when you crank the steering wheel to lock, that shaft on the outside of the turn needs to be replaced. This may sound complicated, but the repair is actually easy enough to do in the driveway with a few hand tools. Replace the whole halfshaft, and don't attempt to repair the boot—it'll just go bad again. Buy a remanufactured halfshaft at a parts store, then take the old one in after the repair. They'll buy it back as a core and sell it to a recycler, who will rebuild it for resale. In all, the fix will probably cost less than a hundred bucks. Sweat the details though; nobody wants a wheel to fall off.

How Rzeppa Joints Fail

Remove the Axle Nut

Install the New Shaft

Replacement shafts are remanufactured old units, so make sure it matches the old shaft. Apply some white lithium grease to the transmission-side mounting surfaces and push the shaft into place. Use only your hands, and be sure it seats completely. If it puts up a fight, pull the shaft out, clean everything thoroughly, and try again. Work the wheel-side shaft into place and be sure it slides into the hub securely. Start the axle nut to hold it in place. Reassemble the disconnected suspension components and torque appropriately, then tighten the axle nut and mount the tire. Lower the car until there's a bit of weight on the tires and then torque the axle nut (see below) down—usually about 150 lb-ft of torque, but check your service manual . Finally, take the car in for an alignment. Things will be out of whack no matter how careful you've been, and a few bucks spent on alignment will make the car safe on the road and save your tires.