mower question

grizz02 · Nov 23, 2023

My son has two ford tractors a jubilee and a 3930 ford , when he uses the 3930 with a 6ft finish mower it breaks the shear bolts almost every time , but when he uses the jubilee he has never had a problem , he ingages it at idle and moves the pto lever slow to let the mower come up to speed but seams to ingage hard , is there a clutch pack inside , or does he need to put a slipper clutch on the pto shaft thks

Janicholson · Nov 23, 2023

The older tractor (probably) has a two stage clutch and he lets the clutch out moderately allowing the mower to get to speed with a bit of clutch slipping. The newer tractor probably has a hydraulically engaged clutch pack and is either on, or off, with quick transition to on. A careful look at an owners manual might find an adjustment for the application allowing the mower more time to get to speed. Also checking the recommended shear bolt grade/specification might assist. Jim

E.B. Haymakin' · Nov 23, 2023

the 3930 is driving way more power through that pto shaft. Be more cautious when using it on the 3930

Destroked 450 · Nov 23, 2023

The 3930 does have hydraulic engaged pto and unfortunately does not have soft engage feature
The engine needs to be at near idle before engaging the pto
One way I start up one of my mowers is the flip the lever and just as the pto starts to engage I flip it off and back on, I do this a few times leaving it on just a little longer each time as the mower spins up, after doing that a few times the mower will be turning enough that I can leave the lever in engaged position
Another thing is to start the mower with it raised and not down in the grass to reduce resistance

grizz02 · Nov 23, 2023

would a slip clutch help with shock load

VicS · Nov 23, 2023

Most of you won't believe it but. Some newer tractors will engage smother if you rev the tractor up and pull the button.

Destroked 450 · Nov 23, 2023

Slip clutch won t help much, if it is loose enough to prevent shearing pins it will slip under heavy load
Most mowers with slip clutches have splines shafts and no shear pins

mower question

grizz02

Well-known Member

Janicholson

Well-known Member

E.B. Haymakin'

Member

Destroked 450

Well-known Member

grizz02

Well-known Member

VicS

Well-known Member

Destroked 450

Well-known Member

Similar threads