The half-shaft is that component which transmits drive from the gear box or the differential to the car wheels. It is comprised, among other things, of two joints allowing the suspension to move up and down, and the front wheels to turn while constantly transmitting the drive. Some half-shafts do not have replaceable joints and need replacing when worn or damaged.
What is the half-shaft?
The half-shaft is that component of the suspension, which transmits the drive from the gear box or the differential to the car wheels. It is comprised of two joints allowing the suspension to move up and down, and the wheels to turn, while constantly transmitting the drive.
When does the half-shaft need changing?
The half-shaft joints, also referred to as the homokinetic joints, gradually wear or brake down when penetrated by water or other contaminants, or when they leak the lubricant as a result of tearing of the rubber housings. If this is the case, the joints must be replaced, however, this may be impossible with certain types of half-shafts. If this is the case, the entire half-shaft must be changed.
How is the half-shaft fitted?
Removing the half-shaft requires disassembling the suspension in order to remove the spline of the external joint of the half-shaft from the wheel hub. Next, the half-shaft is disconnected from the drive unit, i.e. the transmission or - in the case of a rear wheel drive - the rear differential.
Depending on the type, a half-shaft my be connected to the drive unit by means of clamps or screwed to the flange. In the case of a half-shaft attached by means of clamps inside a differential, you must avoid accidental turning of the ring wheel of the mechanism. A half-shaft's end fitted inside it constitutes also the axis of rotation of the satellite wheels of the differential. If this is the case, the satellite wheels may come out of the basket, resulting in the necessity to disassemble the entire drive unit in order to fit them back into place. A new half-shaft is assembled in the reverse order.
What to keep in mind
Given the cost of half-shafts, you should take good care of them, in particular, you should control the condition of the rubber half-shaft joint housings, as their useful life depends on their proper operation.