PEDDERS TALKS CV SHAFTS
Pedders says its comprehensive range of replacement CV Shafts are made to exacting specifications
With the majority of vehicles on our roads today being either front-wheel-drive or all-wheel drive, CV shafts are one of the most common components requiring replacement.
What is a CV Shaft?
Pedders explains CV Shafts are the drive shafts which carry the power from the engine and transmission to the wheels through varying angles.
Pedders says its comprehensive range of new replacement CV Shafts are supplied with Constant Velocity Joints (or CV joints) which are assembled with a specially formulated high temperature moly grease to resist friction and wear, while new premium grade neoprene boots are used to resist abrasion and temperature erosion.
New stainless steel clamps are used, and all of the shafts are made of strictly inspected materials to ensure a long and trouble free performance and coated with a protective surfaces to resist rust, says Pedders.
Further, the CV joints are CNC-machined to ensure proper tolerance with the components guarantying a long, dependable life, while the splines are machined to OE specifications. All shafts include zinc coating, OE style nuts or pins.
How do they work?
CV Joints allow a rotating shaft to transmit power through a variable angle, at constant rotational velocity, without an appreciable increase in friction or play.
They are mainly used in front wheel drive and all-wheel drive cars. However, rear wheel drive cars with independent rear suspensions typically use CV joints at the ends of the rear axle half shafts.
There are two basic applications of CV joints, one near the wheel called the outboard joint and the other close to the transaxle known as the inboard joint. They are also categorised according to their operating requirements.
If a CV joint is fixed and does not move in or out with movements of the driveshaft it is known as a fixed CV joint. If the joint does move in and out, usually up to 40mm, it is known as a plunging CV joint.
Generally speaking, explains Pedders, outboard CV joints are fixed and inboard CV joints are plunging.
There are exceptions to this however there must be at least one plunging CV joint in every drive shaft. Considering their design and the constant loads they bear, it is not surprising says Pedders that CV joints have a limited life and are particularly prone to accelerated wear due to contamination.
CV joints are protected from contamination by air tight rubber boots secured with metal retaining clips.
Failure of these boots is the primary reason for CV joint failure, explains Pedders, stating a split or broken boot will eventually cause the failure of the CV joint in all cases.
Maintenance is usually limited to checking that the rubber boot which covers them is secure and not split or broken. If the rubber boot is damaged, the lubricating grease that the joint is packed with, will be thrown out.
The joint will then pick up dirt and water that will cause the joint to overheat and wear, and the grease can also contaminate the brakes.
In the worst cases, the CV joint may separate, causing the vehicle to lose the ability to drive. Damaged CV joint boots will usually cause a car to fail a safety inspection.
Pedders says its comprehensive range of replacement CV Shafts are made to exacting specifications including European SGS international quality ISO9001, QS9000, VDA6.1 and TS16949 certifications.
They also come with a two-year 40,000km nationwide warranty. Pedders explains its CV Shafts are complete new units – not reconditioned.
Fault finding and diagnosis
Pedders says the two main failures with CV Shafts are wear and partial seizure.
Wear in the outer joint usually shows up as vibration at certain speeds, Pedders explains, stating it is a bit like the vibration caused by an unbalanced wheel.
Wear in the inner joints shows up as a ‘clunk’ when applying power, explains Pedders, or if severe, when lifting off the throttle; while partial seizure causes a strange ‘pattering’ sensation through the suspension.
This is caused by the joint overheating, which in turn is usually caused by the outer joint boot having split or broken, allowing the joint to throw out its grease.
Because CV Joints are similar to sealed bearings and are under enormous loads, contamination caused by split or broken boots is the primary cause of rapid wear and failure, says Pedders.
For further information or a comprehensive check of your vehicle talk to your local Pedders Suspension specialist, or visit www.pedders.com.au