Published on February 20th, 2015 | by Jacks4
Electric PTO Clutches Handy Hints
The two most important requirements for a successful clutch application or installation:
- Anti-rotation device must allow both axial and radial free-play. Failure to allow this free-play will result in field bearing failure. The greater the restriction the faster the bearing will fail.
Mounting bolt torque to be minimum of:
3/8"-24 UNF use Grade 8 bolt torqued to 40/45 lb.-ft. (Grade 5 bolt is unacceptable)
7/16"-20 UNF Grade 5 or 8 bolt torqued to 50-55 lb.-ft. (Grade 5 or 8 bolt is acceptable)
M 10 X 1.50 Class 10.9 torqued to 55-60 N-m.
Install mounting bolt and retaining washer and torque to spec for the clutch to work properly.
Use Grade 5 or Grade 8 bolt only. Minimum torque:
- 7/16 in. UNF bolt is 50ftlb/67 Nm
- 3/8 in. UNF bolt is 31ftlb/42 Nm
- M10x1.5 bolt is 35ftlb/48 Nm
Most applications that mount directly to the crankshaft use a “CCW” for standard mount (pulley away for engine).
A “CCW” rotation is normally used for reverse mounting (pulley towards engine).
If a clutch is mounted incorrectly then the springs will be run in compression and it will cause the springs to fail.
Warning – Anything less than required mounting torque could result in clutch failure, thus voiding warranty.
Jack’s Safety Tips: Before servicing or repairing any power equipment, disconnect the spark plug and battery cables. Remember to wear appropriate safety glasses and gloves to protect against harmful chemicals and debris. View our Disclaimer.