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One Alto Way
Atmore, AL 36504

EMAIL:
sales@altousa.com

PHONE:
251.368.7777

FAX:
251.368.7774

Under acceleration the clutch is slipping. Should I just replace it?

Not always, sometimes the problem is the adjustment of the mechanical linkage or cable, especially if the clutch system in the vehicle has very low mileage. If your customer is complaining of clutch slippage, usually they have prepared themselves for a $300 to $700 dollar repair bill. If you can solve the problem with a simple adjustment, you have saved them money, and added a value that they will not soon forget, "trust in your product or service to them."

When a new clutch cover and disc are installed, the disc varies from 3/8 to 1/2 inch in compressed thickness depending on application. As the cover assembly mounting bolts are tightened, the diaphragm (or levers) move closer towards the center of the clutch disc. As the vehicle is driven, the friction material wears and becomes thinner. As material becomes thinner, the diaphragm (or levers) of the clutch cover moves away from the center of the clutch disc toward the clutch release bearing. If the free play adjustment is not maintained the diaphragm (or levers) will come in contact with the bearing and pressure will be applied to the diaphragm. This will reduce the clamping pressure applied to the clutch disc and will allow the disc to slip under a load. Depending on how long this condition has existed a simple adjustment can correct the problem.

If the vehicle has a hydraulic release system the same condition can occur. However, in this case a simple adjustment may not solve the problem. Some hydraulic systems have an adjustment and some do not. If the hydraulic system does not have an adjustment on the slave cylinder, that system is designed so that when the diaphragm moves closer to the clutch release bearing the fluid is forced back into the master cylinder reservoir. The master cylinder has special valves, which permits this fluid to return.

If the master cylinder is not allowing the fluid to return to the master cylinder reservoir, pressure is applied to the diaphragm and the disc slippage will occur. A quick check can determine if this is the problem on vehicles with an external slave cylinder. Unfortunately with an internal slave cylinder system removal of the transmission and bell housing are necessary.

To complete this test you will need some assistance. If the hydraulic release system has an external slave cylinder, you can push the rod inward toward the slave cylinder. Have someone remove the top of the master cylinder reservoir and look for the fluid to return to the reservoir. If no fluid returns to the reservoir the master cylinder should be replaced.