4320 Transmission Oil Leak

   / 4320 Transmission Oil Leak #1  

Rayder

Bronze Member
Joined
Mar 11, 2005
Messages
53
Location
Oregon
Tractor
John Deere 4320
Noticed my 4320 leaking transmission oil in front of the rear axle (below the seat area). Crawled under the tractor and found a sensor on the left side of the transmission where the oil seems to be coming from. There is a two pronged wire that looks like it is supposed to plug into the sensor, but was hanging loose.

I guess the first question is what is the purpose of the sensor (temp?). How do I know if it is working or needs to be replaced? Should I just plug the wire back in, tighten it up and see if that stops the leak? Anything I should watch out for as far as torque on this sensor?

Tractor is still under warranty, but if this isn't a big deal, I would rather not hassle with taking it in to the dealer.

Any advice is appreciated.
 
   / 4320 Transmission Oil Leak
  • Thread Starter
#2  
Here's a little more info after a closer look. The sensor I mentioned (if it's really a sensor) is located about 1 inch above the spot where the linkage for the MFWD shift enters the transmission.
 
   / 4320 Transmission Oil Leak #3  
If I correctly understand your description, that is the switch that tells the instrument panel when your front wheel drive is engaged.

Try this - With the switch unplugged, turn your key on and engage and disengage the front drive. If the dash light doesn't go on and off, then plug the connector in and repeat. That should confirm the identification.

It sounds like there may be a damaged O-ring behind the switch.
 
   / 4320 Transmission Oil Leak
  • Thread Starter
#4  
Ding Ding Ding ... RogerH wins the prize. THe MFWD light on the instrument panel was not working ... plugged the wire into the sensor and bingo.

I've been moving brush/branches around with my grapple and I bet I ran over a branch that came up and knocked that sensor. There is a plastic part that protrudes from the bolt, and it looks ok, but I probably hit it hard enough to damage it internally. Probably the best thing to do is replace the sensor.

Thanks a bunch ... this site is great!
 
   / 4320 Transmission Oil Leak
  • Thread Starter
#5  
$12 sensor and o-ring later, problem solved.

That's the kind of problem I like, cheap and easy (thanks to a little help).
 
 
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