John Deere 8640

[Wyoming rancher]

Hi, has anyone ever had to jump start a starter solenoid on a John Deere 8640 or similar tractor? Was curious on the procedure?

 

[casecollectorsc]

Hi, has anyone ever had to jump start a starter solenoid on a John Deere 8640 or similar tractor? Was curious on the pro

Hi, has anyone ever had to jump start a starter solenoid on a John Deere 8640 or similar tractor? Was curious on the procedure?

Neighbor got killed when the 4440 he was jumping at the solenoid ran over him. Make damn sure you know the tractor is in neutral.

 

[wore out]

Hi, has anyone ever had to jump start a starter solenoid on a John Deere 8640 or similar tractor? Was curious on the procedure?

Tell us "the rest of the story"!

They used a 12 Volt "positive engagement" starter and the procedure for starting it by jumpering at the starter solenoid would be the same as most any other such starter, EXCEPT that there should be a plastic safety cover over the solenoid terminals to prevent this.

Accidently cranking it gear is particularly dangerous with such tractors because the clutch is hydraulically engaged.

When first cranked it will act as if it is in neutral, then as soon as it "catches" and gains speed and the transmission pump begins to supply oil the clutch will engage and it will be "over" for anyone or any thing in the tractor's path!

 

[Wyoming rancher]

Tell us "the rest of the story"!

They used a 12 Volt "positive engagement" starter and the procedure for starting it by jumpering at the starter solenoid would be the same as most any other such starter, EXCEPT that there should be a plastic safety cover over the solenoid terminals to prevent this.

Accidently cranking it gear is particularly dangerous with such tractors because the clutch is hydraulically engaged.

When first cranked it will act as if it is in neutral, then as soon as it "catches" and gains speed and the transmission pump begins to supply oil the clutch will engage and it will be "over" for anyone or any thing in the tractor's path!

Thank you! The reason I was asking because a friend of mine years ago did get run over and killed him. I don't understand why in was in a hi



gear and full throttle? He farmed all his life. He used a screw driver to jump it. Thank you for sharing and pointing out how dangerous this is.

 

[Brendon-KS]

Thank you! The reason I was asking because a friend of mine years ago did get run over and killed him. I don't understand why in was in a hi
gear and full throttle? He farmed all his life. He used a screw driver to jump it. Thank you for sharing and pointing out how dangerous this is.

You see this a lot - even on these forums. A person comments that they've done (fill in the blank with a dangerous action) for years and never had a problem so therefore it must be safe for them to do. No matter how conciencious or experienced a person fancies himself as there can easily be that time when something gets overlooked that leads to a bad ending. Lots of experienced farmers get killed on the job because eventually the bad habits they've gotten away with for years catch up to them.

 

[Fixingfarmer]

All it takes is a mistake once.

 

[wore out]

Thank you! The reason I was asking because a friend of mine years ago did get run over and killed him. I don't understand why in was in a hi



gear and full throttle? He farmed all his life. He used a screw driver to jump it. Thank you for sharing and pointing out how dangerous this is.

Sorry to hear of the loss of your friend.

 

[Tx Jim]

DITTO my condolences concerning your deceased friend.
Shorting across starter with trans in gear was performed often enough to cause enough harm that JD engineers on later models such as 55 series added a safety valve so clutch pedal must cycled after engine is operating before Perma-clutch can receive hyd pressure for engagement

 

[Wyoming rancher]

DITTO my condolences concerning your deceased friend.
Shorting across starter with trans in gear was performed often enough to cause enough harm that JD engineers on later models such as 55 series added a safety valve so clutch pedal must cycled after engine is operating before Perma-clutch can receive hyd pressure for engagement

Thank you! Couldn't understand how this could happen if jumping with a screw driver he wouldn't have noticed the tractor starting to move when he jumped it and stopped so he didn't get run over.

 

[Tx Jim]

Thank you! Couldn't understand how this could happen if jumping with a screw driver he wouldn't have noticed the tractor starting to move when he jumped it and stopped so he didn't get run over.

once engine starts operating at RPM's much above idle speed with trans in a gear things start happening rapidly!

 

[redtom]

My neighbor was killed doing that with a WHITE 4x4. Had to go between front and rear duals to do it. Rolled him in between the duals went through the back wall of shed. With him going round and round in wheels. Accross field till it got stuck. The site was so bad they had to run a disc up and down the path it went to cover the carnage.