One of the most highly stressed parts of the drive line is the CV joint/outer axle. This is generally the first component in the drive line to fail if the manufacturer’s specifications are exceeded.
To reduce the possibility of costly damage or finding yourself stranded in some remote area with strange noises coming from your credit card, attention needs to be paid to minimising some of the strain on your CV joints.
Have the steering lock stops been altered to obtain a better turning circle? Keep in mind that CV joint manufacturers generally specify a maximum operating angle of 30 degrees. The steering angle of many factory built 4x4s exceed this important measurement. Some units on full lock register as much as 36 degrees in standard trim. Has a raised suspension kit been fitted? This modification alone may cause the CV joint to exceed the allowable limit on full droop. It is recommended fitting a differential lowering kit to minimise future damage to your vehicle.
Obviously fitting larger diameter wheels and tyres increases the load on the entire drive line system, a strain that can exceed the capacity of the CV joint. Driving in a straight-ahead position is of course the minimum load possible on the entire transmission however, what we need to aim for is to reduce as much as possible ‘full-lock full-power’ operation in 4w drive, the strain on the CV is increased dramatically as the steering angle reaches full lock.
We need to avoid at all costs driving on hard surfaces in 4wd due to transmission wind-up, a situation where some of the tyres must skid in any turning manoeuvre which places enormous strain on all components. When climbing a hill in 4wd trying to get traction if one front wheel leaves the ground, the free wheel is driven at double the normal speed (due to normal differential action) and when it lands the shock load can easily exceed the designed limit of any component.
The above situation is one where a front ‘E’ lock’ Terrain Tamer locking differential would minimise that possibility. Keep in mind that standard vehicles with original engines, wheels and tyres and unmodified suspensions systems rarely suffer drive line damage. Understanding some of the strains imposed on the C.V. joints may help to encourage a modified driving approach with less damage to your bank balance!
Check out the video from Terrain Tamer which delves fatigue tests, load bearing considerations and CV joint tests that Terrain Tamer undertakes on their parts.