Clutch Linkage Adjustment

 

Clutch Linkage Adjustment

 

 

Is your manual trans Chevelle’s clutch slipping, gears clashing on shifts, or point of pedal “grab” not right? Hopefully all it needs is a simple clutch linkage adjustment. Improper adjustment can cause excessive clutch slipping, leading to premature wear of the disc, or at the other extreme, not fully releasing while causing gears to clash and premature throwout bearing wear. One simple test is to hold the clutch pedal off the floor ½” with the engine running and vehicle stopped. Shift between first and reverse several times. This should be smooth without any gear clash. Then while traveling along in high gear about 25-30 mph, disengage the clutch and rev the engine to 2500-3500 rpm then  pop the clutch while simultaneously flooring the gas pedal. Engine rpm should decrease until it matches the vehicle speed.  If the engine speed increases, excessive clutch slippage is occurring. If both these tests are OK, your clutch linkage is probably at least close to proper adjustment and in good condition.

The portion of the clutch linkage adjustment on stock Chevelles is located under the vehicle, close to the bellhousing. Adjustment is performed by loosening a locknut and turning a threaded rod into or out of a pivot block or shaft, then tightening the locknut. Many people prefer to adjust theirs to where the point of  pedal “grab” feels right to them. Per GM service manuals, the proper adjustment on Chevelles is achieved in this manner: remove the return spring(s); loosen the locknut; turn the adjustment rod until the release (throwout) bearing lightly contacts the pressure plate fingers (resistance is felt); back off the adjustment rod 3 full turns away from the start of resistance; tighten the locknut; and reinstall the return spring(s). Pedal free play (distance between the upper stop and pedal lever where the point of resistance is felt from the release bearing contacting the pressure plate fingers) should be 1 1/8” to 1 ¾”. This is easier to determine with the return spring(s) removed.


With the clutch linkage properly adjusted, and you still have excessive slippage or gear clash, there are likely other more serious problems. With slippage you probably need a new clutch disc or clutch and pressure plate assembly. It’s always a good idea to replace the throwout bearing whenever replacing any clutch parts and check the flywheel condition. If the gears clash, you could have trans linkage problems (if you’re lucky), or internal trans problems. Here’s hoping a clutch linkage adjustment eliminated the problem