Q: Is there a root cause for improper clutch adjustment?
A: Yes, hydraulic clutch release linkages and the need for education are the root cause for this trend. Hydraulic release linkages give very limited or zero feedback to the driver or the technician that the clutch requires adjustment. All truck manufacturers have moved from mechanical clutch release linkage to hydraulic release linkage for other benefits like decreased clutch pedal effort for the driver. Many top-level technicians and drivers were taught to identify the need for clutch adjustment based on in-cab clutch pedal “free play.” When the clutch “free play” was reduced it was the driver’s responsibility to write up a service report and bring the truck in for clutch adjustment service. Each time a technician did a service they would wiggle the clutch pedal for a quick “free play” check. This worked for years on mechanical clutch release linkage. Unfortunately, hydraulic release linkages do not provide that same tactile feedback. So, often, drivers and technicians don’t catch clutches that require adjustment before they start to slip and the damage is already done.
Information provided by: Betts Truck Parts & Service