Published on February 20th, 2015 | by Jacks7
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.
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