CV (constant velocity) Joints

CV Joints (Constant Velocity Joints)

If you are considering buying a used vehicle equipped with CV joints, be sure to check for leaking or damaged CV boots.

CV joints are used on many types of vehicles especially FWD, 4X4 and AWD (all-wheel drive). CV joints attached to the drive axles allow power from the final drive assembly to be transmitted to the tire and wheel assembly thus powering the vehicle down the road. The CV joint allows the axle to flex or change angles to allow you to steer around a corner while transferring torque to the road. Also, these angles change as the vehicle suspension increases or decreases its ride height as road surfaces and load changes.

The longevity of the CV joint depends on its lubrication which is a special designed lubricant that is sealed inside a boot. The boot looks similar to a ribbed billows surrounding the inner and outer joints or the drive axles. When the boots leak joint damage will occur quickly. Remanufactured axle assemblies or boot kits are available as a repair. Either repair choice is not cheap. (Call or search online for prices/estimates).

If boots are leaking, damage to the joint may cause a rapid popping noise, especially while turning a sharp corner or accelerating. If popping occurs, forget the boot kit ‘fix’ and go with the axle assemblies.

4 X 4 &/or AWD

4-wheel drive (4wd)
The 4wd gives the driver the option of driving in 4wd or two-wheel drive (2wd). These vehicles can be basically a front wheel drive (fwd) or rear wheel drive (rwd). Some also, in addition to the fwd/2wd option, have a high and low range option.

All-wheel drive (awd)
The awd vehicles do not have an option of 4wd or 2wd. They are in 4wd at all times and transfer power to the wheels with the most traction through a viscous clutch.

Most manufacturers offer both types in some of their product lines.

Cold Weather Car Problems

Two common complaints in cold weather are doors that stick closed and the heater blows cold air -- no heat.

For doors that stick:
Before cold weather clean the door and trunk gaskets (rubber seals) and the surface the gaskets meet with soapy water. Rinse and dry completely.
(* A Must: ...Leave the doors open until surfaces and seals are completely dry.)
After seals and surfaces are completely dry, spray with a silicone spray that can be bought at any auto parts store, Wal Mart, etc.
Repeat this at least two times....and now you are ready for cold weather. If you live in an area of an extended cold weather period recoat both surfaces with silicone spray every 4-6 weeks.
Note: If the weather is already cold, this procedure may be done in a heated garage where the seals and surfaces will completely dry before the silicone spray is applied.
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If your heater is blowing cold air instead of warm/hot the first thing to do is:
* Check coolant level. If it is low add coolant and pressure check the cooling system for leaks(hoses, radiator, thermostat housing, and don't forget the water pump and freeze plugs) .
On many vehicles low coolant will not allow coolant to flow through the heater and the engine temperature may show cold.