John Deere 3720 Front Axle leaks

   / John Deere 3720 Front Axle leaks #1  

marshallcro

Member
Joined
Dec 12, 2013
Messages
46
Location
Stanfordville,ny
Tractor
John Deere 3720, Farmall Cub, Bobcat 3400
Can someone tell me how tough a job it is to change the front axle gaskets on a John Deere 3720. I have a oil leak on both sides and I would like to talk to someone who has done this job before I tackle it.
 
   / John Deere 3720 Front Axle leaks #2  
I can't help you with your 3720 but if you go over to the John Deere owning operating section there's a couple threads on changing out seals on a JD 4300. Not the same but probably similar.
 
   / John Deere 3720 Front Axle leaks #3  
I just changed on the right side. Remove the 8 bolts that secure the hub assembly. Pry at the 2 grooves where the parts meet and remove the hub from the tractor. On the bench support the hub and remove the snap ring. Drive the shaft out of the bearing and splined gear. It wont go easy. There is only one snap ring holding all the bearings, spacer and gear together. I know I questioned this as it was not easy to drive the shaft out. Replace the seal and reassemble. I used grey RTV gasket sealer when bolting it back up. Good luck.
 
   / John Deere 3720 Front Axle leaks #4  
Do you need a press or can it be achieved with a block and hammer?
 
   / John Deere 3720 Front Axle leaks #5  
Ideally it should be down with a press. The bearings are pressed into the shaft.

On another note. A quick hack that might fix it is to drill a small hole in the fill plug. These seals notoriously leak because the case is not vented. In theory it was thought that the pressure would make a tighter seal but it ends up venting through the seals instead.

JD now makes a vented plug but its stupid expensive and the same can be done with a 1/16 drill bit. Both my JD 4310 and 4400 had front leaking seals and after I vented them the leak became so nominal that it wasn't worth digging into them to replace the seals.
 
 
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