John Deere 6420 powerqaud 24 speed

[parrott]

Tractor has some issues when temperatures are vary hot out side 3-third gear disappears in all ranges after tractor has been running for a couple of hours. It returns after tractor cools down. Rad has been cleaned coolant level is at the MAX mark. Oil levels are good. This becomes a real issue if travelling down a hill and it suddening fades away. Indicator on dash still shows "3" but its like the tractor is in neutral.

Just wondering what else can be down to fix this. Dealer has been no help.

 

[rutwad]

What is the powerquad 24 speed? 6 ranges x 4 gears each, push select between gears with no clutch?

 

[parrott]

That is correct 6 ranges with electronic 4 speed select.

 

[AKfish]

Tractor has some issues when temperatures are vary hot out side 3-third gear disappears in all ranges after tractor has been running for a couple of hours.

It returns after tractor cools down.

This becomes a real issue if travelling down a hill and it suddening fades away. Indicator on dash still shows "3" but its like the tractor is in neutral.

If I'm understanding the problem correctly... When the tractor gets hot (engine or tranny?) the transmission disengages - neutral - and the tractor will not move until you let it cool down?

That's the situation?

Sounds like a transmission "fail-safe" override. Is there an electronic circuit or computer module that monitors the engine and transmission, etc.?

Could be a sensor or computer threshold setting that kicks in (prematurely) and disengages the transmission to avoid overheating damage to the system.

The dealer should be able to check the system for that kind of problem. If it's computer controlled - there should be a "record" of the problem that can be downloaded and analyzed.

AKfish

 

[parrott]

Transmission still indicates third gear but tractor will not move select any other gear and no problem. No codes have been set.

 

[AKfish]

Transmission still indicates third gear but tractor will not move select any other gear and no problem. No codes have been set.

OK... and the dealer checked out the 4-speed electronic shift controller?

And if you change the range selector - what happens?

AKfish

 

[jd110]

It's hard to imagine no codes being stored for this problem. Has your dealer connect a computer to test for codes? Any time the tractor is in gear without wheels turning, a code should be generated. It sounds like you either have a leak in the third gear clutch pack, or maybe a bad shift solenoid. Either one woul dbe worse when hot. Does it ever seem to slip in third gear, or is always a sudden loss of motion? If always sudden, I would suspect eletrical problem. Either a bad solenoid or a loose connection between computer and solenoid.

 

[parrott]

When it happens there is no warning that its slipping just full loss of motion. Drop down a gear to second or up to fourth and everything is fine in any range and everything is fine. Let it cool down and it comes right back. I would agree that there should be something stored in the computer but dealer says nothing. Tractor has less than 2000 hours