Clutch release bearing for your car

A sliding fit for clutch engagement: the release bearing

The connection between engine and gear in cars is constructed as a separable clutch. A rotating unit is separated in the middle when the rotation is still taking place. This complicated mechanical process needs an adequate bearing arrangement on all sides. Part of this arrangement is the release bearing.

Construction and location of the release bearing

The release bearing is conceived as a needle bearing, an oblong bushing with cylindrical rollers placed on the inside, kept in their place through lubrication. Once installed, the needles cannot fall out because of the internal gear shaft. The release bearing is a clutch component installed between engine and gear. It sits in front of the clutch pressure plate and when the clutch is engaged, it presses the lamellae, releasing the spring pressure on the clutch pressure plate upon which the clutch separates the torque from the engine to the gearbox.

Release bearing defects

The delicate bearing needles can lose their precision over time. Friction and strain alters their size and they can bend slightly. A roller jumping out of the bushing is fatal. Although a small component it can cause extensive damage in the gearbox. When the release bearing approaches its wear limit, it makes itself heard by a rhythmical whistling sound. The whistling is initially soft, gradually becoming louder. The clutch no longer disengages properly and a resistance can be felt when stepping on the pedal.

Release bearing repair

The release bearing is never repaired but always completely replaced. The cause of a defective release bearing is almost always the same: the needle bearing was not renewed on occasion of the previous clutch replacement. It is very important always to replace the clutch as a set. Every step on the clutch pedal wears the spring plate down gradually. The release bearing is equally put under strain. Clutch plate and release bearing wear simultaneously. Therefore: even when the clutch plate looks fine, it should be replaced along with the release bearing. This ensures a defined new condition of the entire system. The removal of the release bearing requires the removal of the clutch plate, making maintenance of this component very similar to general clutch maintenance.

Safety comes first

If the engine-transmission combo is not entirely removed for the clutch replacement, a clutch is always repaired from underneath the car. To allow the DIY'er to work under the car successfully and safely, certain measures are necessary. The car must stand securely, guarded against sliding or falling from the support construction. Timber blocks or cobblestones are definitely unsuitable. If a lifting platform is not available, professional car jack stands should be used. Ramps are less suitable. For clutch replacement the left front wheel must be removed. If the car is standing on two ramps, this compromises a stable position. The car must be placed on the stand on the right jack supports. If the stand is placed somewhere else on the underbody, this might cause:

• damage to the metal plating
• distortion of the bodywork

Particularly affected are always the internal side sills. Other contact points than the jack supports easily dent. In the worst case, a faulty placing of the jack stands causes warping of the entire bodywork. This generally means a financial total loss. If the engine must be removed for the replacement of the release bearing, the following parts should also be replaced:

• timing belt
• spark plugs
• manifold gasket
• valve cover gasket
• oil pan gasket
• thermostat
• temperature sensors
• if necessary, coolant hoses

Even if these components appear intact or their replacement interval is not due yet, they should be renewed. The occasion is simply too favourable not to use of it for replacing these cheap though important components.

Costs for a release bearing

A single release bearing costs between. 15 – 70 EUR (± £13 - £62) for average cars. In luxury cars, e.g. Porsche or Jaguar, a release bearing can cost more than 150 EUR (± £133). The complete clutch set, depending on car, starts at 70 EUR (± £62). If the dual mass flywheel is already past ¾ of its life span,fit should be replaced as well. You save yourself a lot of work when its replacement interval is due.