Somewhat Easy CV Fix

Introduction

This is a relatively easy and very inexpensive way to restore your front constant velocity (CV) joints. The front suspension has a pair of axle shafts (half axles) that transfer the drive from the transaxle to the front wheels. Front wheel drive and 4 wheel drive vehicles use jointed axles so drive can be applied to the front wheels that must move up and down via the suspension and also turn side to side when steering the car.

This is accomplished by incorporating a pair of constant velocity joints on each half axle. These CV joints must handle extreme forces as the drive train uses them to apply the engine torque to the front wheels. The torque must be delivered in a smooth and quiet manner in order the provide a pleasant driving experience whether the driver is accelerating, braking, turning or negotiating rough roads, hard cornering and parking.

All this is magic is managed using 6 rather large ball bearings within each CV joint! These ball bearings roll back and forth across machined grooves (races) inside the CV’s and give the joints the flexibility they need to get the job done. As a result the balls must apply lots of force on the races. Special grease coats the entire assembly to minimize wear. Flexible rubber boots keep the CV’s clean and dry.

Galloping Horses

In time and during normal operation, these CV’s will show wear and begin to get noisy. The rubber protective boots will crack and tear open allowing moisture and road grim in and contaminate the grease inside. This will accelerate the wearing process. The noise is caused by shallow pits forming on the races where the balls change direction on their normal track back and forth as the axle turns. The pits get deeper and deeper acting like detents that take some force to “pop” the balls out of them and giving a click sound 6 times every rotation of the axle. This click will get louder the more torque is applied, the harder one corners and the more they wear. The boots help to muffle some of the clicking noise, so when the boots tear suddenly it’s as if a herd of horses is galloping along side your car when you make that right hand turn.

The Fix

Remove both half-axle assemblies- right and left from the car. Remove the boots from the outer CV’s. Remove both OUTER CV’s from their shafts by carefully driving the inner race off the end of the shaft.

Clean up and fully inspect each of the CV assemblies and apply new CV grease. Slide the boots back onto the axle shafts. Move each CV to opposite axle shaft it came off of and reinstall them so the races of the inner and outer CV’s are out of phase with each other. Slide the boots off the inner CV’s just far enough to see the inner race for comparison.

Slide the outer CV’s (now mated to other shaft) in place until they seat. Clamp down each of the boots securely. Reinstall the half-axles into the car making sure to tighten the axle nuts to the correct torque. Complete the usual half-axle install procedure as described elsewhere and fully safety test the vehicle.