Premium Quality Guaranteed:SACHS Clutches for Light Commercial Vehicles.

Light commercial vehicles have to deliver top performances day after day. Be it short distances with stop-and-go city traffic or hours on the freeway – with SACHS clutches, transport vehicles are perfectly equipped. They guarantee comfortable setting-off characteristics and effectively dampen vibration noises.

Clutch kit for light commercial vehicles

SACHS clutch kit for light commercial vehicles

Today, the service life of individual clutch components is almost identical. The SACHS clutch kit takes this into account by providing all relevant components that are required for clutch replacement, namely clutch pressure plate, clutch disk, and release bearing.

The kit's scope of supply includes a special grease for assembly. It guarantees perfect functioning after the replacement. With the SACHS clutch kit, clutch replacements can be performed safely, effectively, and swiftly.

XTend clutch pressure plate

SACHS XTend clutch pressure plate

Even the highest-quality and most durable clutch is subject to operational wear and tear. This is where the XTend clutch pressure plate made by SACHS comes in: It provides automatic wear compensation. How it works: The XTend clutch pressure plate separates facing wear from the movement of the diaphragm spring. The compensation mechanism constantly registers the reduction in facing thickness and reliably compensates this distance by turning an adjusting ring. This ensures a constant balance of forces and extends the service life because the facings can be subjected to more wear. The XTend design provides an additional advantage: In case of operational wear, the axial installation space required for the clutch system is reduced thanks to the application of XTend.

Pilot bearing

SACHS pilot bearings

The pilot bearing, also referred to as guide bearing, is predominantly responsible for the functioning of the clutch. As a ball bearing, it guides the transmission input shaft and is thus predominantly responsible for the functioning of the clutch. If wear results in an angular offset, the shaft is not properly supported anymore, which may lead to clutch defects. SACHS offers pilot bearings for all common vehicle models. When replacing the clutch, the pilot bearing should always be inspected and, if required, replaced as well.

Damage evaluation

Clutch slips

Clutch slipping may have various causes. For detailed information on the damage evaluation, please go to the workshop tip: "Clutch Slips".

Clutch does not separate

If the clutch does not separate, the cause is not necessarily the clutch. Frequently, the cause can be found in the clutch release system, the pilot bearing, or installation errors. For detailed information on the damage evaluation, please go to the useful tip "Clutch does not separate".

Clutch grabs

Clutch grabbing is not necessarily caused by a defective clutch. For detailed information on the damage evaluation, please go to the workshop tip: "Clutch Grabs".

Clutch noise

Clutch noise such as whistling or clunking is not always an indication of a defective clutch. Whistling noises may e.g. also be caused by off-center contact of the clutch release bearing, non-centered transmission input shafts, or defective pilot bearings.

Clunking noises may occur in case of load changes, e.g. if clutch disks with pre-dampers are installed. These noises do not impair the function or service life of the clutch disk.

Incorrectly installed parts or the installation of the clutch disk in an incorrect installation position can also lead to noise generation.

Therefore, it is recommended to examine the following questions:

  • Was the correct part installed?
  • Was it assembled in the correct installation position?
  • Are pilot bearings installed and OK?

For additional information on clutch noise and expert evaluations, please go to the workshop tip: "Clutch Noise".

Problems in the clutch environment

Problems caused by components in the clutch environment mostly indicate that important points were forgotten or overlooked during clutch replacement. Therefore, it is necessary to inspect the following parts for function reliability and/or wear:

  • Pilot bearing
  • Guide tube
  • Clutch release system

FAQ about clutches

What tasks does the clutch do?

The clutch has a wide range of tasks in the vehicle. It connects the mass to the engine without jerks, interrupts the power transmission between engine and transmission when the vehicle stops, and interrupts the power flow to change the transmission ratio. Additionally, it provides vibration damping and overload protection.

What are the components of a clutch?

A complete clutch consists of flywheel or dual-mass flywheel (DMF), clutch disk, clutch pressure plate, and clutch release bearing.

Where is the clutch located in the vehicle?

Location of the clutch in the vehicle

The clutch is located between the engine and transmission.

How does the XTend clutch pressure plate work?

XTend clutch pressure plate

The XTend clutch pressure plate made by SACHS provides automatic wear compensation by separating facing wear from the movement of the diaphragm spring.

Facing wear changes the installation position of the diaphragm spring as the pressure plate moves towards the flywheel. As a result, the leaf springs are shifted axially and move into a steeper position; the contact pressure and pedal forces increase. Every time the clutch is engaged, the housing stop registers the facing wear and lifts the retaining spring off the adjusting rings by the amount of the wear path. The wedge-shaped slide (pulled by its extension spring) moves into the newly formed gap and locks the retaining spring in the raised position. When disengaging the clutch, the adjusting ring pair is axially relieved. Due to the prestress of the adjusting ring spring, the lower adjusting ring rotates until the upper ring is in contact with the retaining spring again. The diaphragm spring has returned to its original position and the facing wear has been compensated.

What aspects have to be considered when replacing an XTend clutch pressure plate?

Always use a special tool for replacing the XTend clutch.

During disassembly, keep in mind that the housing stop is lifted off the clutch housing. If it is not released, the adjusting mechanism is triggered during disassembly so that it cannot be reset anymore. Since the facing wear is mechanically memorized in the clutch pressure plate, it is only possible to reinstall the unit that has already been used (clutch pressure plate and disk). If a new clutch disk is required, the clutch pressure plate must be replaced as well. Since the compensation mechanism of the clutch pressure plate that has already been used cannot be reset, the clutch would not separate.

Why should I install the XTend clutch with the aid of a pretensioning tool?

To ensure that the readjustment mechanism works properly and is not wedged. That way, stress-free installation is guaranteed.

What aspects have to be considered when assembling the clutch?

The screws that secure the clutch pressure plate to the flywheel have to be tightened and/or loosened alternating crosswise. Assembly brackets and/or transport safety devices have to be removed after the installation. Also, the clutch facings should be free from dust, dirt, oil, and/or grease. Check the correct centering position of the transmission bell housing relative to the engine housing in order to avoid misalignment.

What must be considered when installing a clutch disk?

Prior to the installation of the clutch disk, a lateral run-out tester should be used to ensure that the lateral run-out of the clutch disk does not exceed 0.5 millimeters. Find detailed information on the lateral run-out tester in the workshop tip: ”Clutch disk check”.

What factors may adversely impact the service life of a clutch?

The service life of a clutch for instance depends on the applied stress and driving style. The clutch is e.g. adversely affected by setting off in a gear too high or at a speed too high, or by holding the vehicle on a hill, with the clutch slipping. Furthermore, decelerating via clutch through shifting down or overloading the vehicle and/or the trailer should be avoided. Also avoid setting off on extreme inclines in rapid succession and frequent maneuvering.

When does a clutch separate perfectly?

In order to examine the separating characteristics, disengage the clutch with the engine idling. Wait for three seconds. Afterwards, the reverse gear should engage without noise (important: immediate engagement of the reverse gear always results in shifting noise).

When does a clutch slip?

Before the test, you should take the vehicle for a short drive, operating the clutch several times in order to heat up the clutch to operating temperature. Afterwards, firmly apply the parking brake, engage the highest gear, and accelerate in the disengaged state until an engine speed of approx. 2 000 rpm is reached. Maintain the speed and quickly engage the clutch.

If the engine is stalled, the clutch's transmission capacity is OK. To avoid overload, only repeat this procedure once.

Further information