Repair 7

Driving any automobile is nothing, if not an exercise in constant blind faith. Just the fact that any soccer mom in the world can take a 50 mph curve without wondering what would happen if a tire blew, a ball joint broke or an axle-shaft snapped is testament to the pragmatic advantages of deliberate ignorance. Still, it never hurts to be prepared for any eventuality, especially if you find yourself in circumstances where breakage is likely.

Open Differential, Accelerating in a Straight Line

Most cars use "open" differentials, which route power to the wheel with the least traction. If you break an axle-shaft or constant velocity joint in a front-wheel drive car with an open differential while accelerating in a straight line, then power will simply flow into the broken axle and spin it. The engine will rev and the axle will spin, but the car wont move. The same goes for front axle-shafts in a 4WD truck, but if the axle tube itself breaks, then odds are that your truck will nose-dive into the road.

Locked Differential, Accelerating in a Straight Line

Many performance cars use locked, limited-slip or "torque biasing" differentials. Locked axles are just that; the left and right wheels always turn at the same speed. Limited-slip differentials can transfer some or all of the power to the wheel with the most traction -- the one spinning slower -- and torque-biasing differentials can transfer some, but not all of the power. With any of these differentials, the car will suddenly veer in the direction of the broken axle since the other wheel is the one doing all the pushing.

Open Differential, Accelerating Out of a Curve

If the axle-shaft is on the inside of a curve -- the right side for a right-hander, left for a left-hander -- while accelerating out of a curve, the vehicle will most likely dart inward toward the curve. Front-wheel drive cars and trucks in 4WD naturally exhibit a certain amount of understeer as the front tires struggle to both accelerate the car and keep it turning. Should the axle-shaft break on a front-wheel drive car, itll quickly-turn into a no-wheel-drive and probably exhibit neutral handling. A 4WD truck or all-wheel drive car will suddenly turn into a rear-driver, which can result in snap oversteer and a probable spinout if the driver doesnt lift off the gas soon enough.

LS or TB Differential, Accelerating Out of a Curve

Front-wheel drives with a limited-slip or torque biasing differential will exhibit a somewhat more severe oversteer condition as power flows from the inside tire to the outside. A clutch-type limited slip may induce a severe oversteer condition and possible spinout, if its powerful enough to transfer all of the engines power to one wheel. The same goes for all-wheel cars and 4WD trucks with an LS or TB differential, but far more so.

Locked Differential, Accelerating Out of a Curve

Fully locked front differentials will act a bit differently than those that allow the wheels to spin at different speeds. This is especially true off-road, which is the only place youre likely to see anything with a locked front differential. Cars have differentials because the outside tire has to turn faster than the inside tire; if you lock the differential, the inside tire will always spin while turning and contribute little to no traction. Under these circumstances, the truck may break either the inside or outside axle, depending on the conditions.

If the inside axle breaks, all the power will go to the outside tire, inducing an understeer condition. If the outside axle breaks, that tire will gain traction while the inside tire continues to spin, inducing a neutral to understeer condition. One caveat though, a locked differential may do exactly the opposite, particularly if the truck lacks the power to spin the outside tire while turning, or spin the inside tire during a tight turn.

Axle shafts are used on most non-commercial vehicles to allow the drive wheels of your vehicle to move in a circular manner. The shafts are located in your tires wheel well, near the differentials. They stretch across the bottom of the car, connecting two wheels together. Obtaining a measurement for an axle shaft is necessary when the axle shafts need to be replaced.

Instructions

1

Locate the axle shaft in your tire well. The axle shaft will have a large, grooved bearing near the center of your tire.

2

Place one end of the measuring tape at the edge of the grooved bearing of the axle shaft. Have someone hold the tape measure in place.

3

Extend the tape measure across the axle bearing until you reach the connected tire. Measure the length based on the distance from one tires grooved bearing to the other tires grooved bearing.

The axles in your car are complex parts that are necessary for the wheels to move effectively. If they stop working completely, it can be very dangerous for anyone in the car. Luckily, when an axle is not working properly, it makes a distinctive sound that you can periodically test for. Set aside time every few months to check the axles.

Instructions

Checking the Car for a Broken or Cracked Axle

1

Eliminate all sounds from the car. Turn off the radio and keep conversation to a minimum. You will be listening closely for noises and need full concentration.

2

Start the car. Turn the engine on and put the car into drive.

3

Turn the steering wheel all the way to the left. Slowly drive forward with the steering wheel still turned and listen for a clicking noise.

4

Turn steering wheel all the way to the right and drive forward listening for a clicking noise. If you heard even the faintest clicking noise on either side, your axles are probably in need of repair.

5

Park the car and examine the axles for cracks or grease. If the axles, which are located inside the wheels, are cracked or covered in grease, it is very likely your axles need to be replaced.