jimgerken
Veteran Member
I was losing a little oil for a few weeks and finally got under the JD 3720 to trace it down. Not what I expected -- the large cover (approx 2 feet long by 9 inches wide) on top of the hydrostatic transmission which is held down to the main transmission casting by at least 12 capscrews, was loose. Every fastener was loose by about half a turn. Did some checking and found that the cover part is also the 3-point upper pin 3-position thing. So the attachments were pulling on the loose cover. Yikes! The cover is cast iron, the main trans casting is aluminum. So there could be some thermal expansion stress working the two apart, but that is hard to believe really. I am thinking they were never torqued completly. Most of last year the tractor had the backhoe on, which has nothing to do with the top link point, so its weird it loosened up then. The tractor is 2.5 years old and has 565 hours on it.
Repairs: Removed the capscrews one by one, cleaned them, blue locktited, and reinstalled with about 30 foot pounds of torque. Some (3 or 4) could not be removed due to interferences with other components, so those few were simply torqued. To get to the screws, I had to remove the seat and suspension. The capscrews were M10.
Four of the screws were accesible from the back of the tractor, so you COULD check yours easily. See attached photo.
Repairs: Removed the capscrews one by one, cleaned them, blue locktited, and reinstalled with about 30 foot pounds of torque. Some (3 or 4) could not be removed due to interferences with other components, so those few were simply torqued. To get to the screws, I had to remove the seat and suspension. The capscrews were M10.
Four of the screws were accesible from the back of the tractor, so you COULD check yours easily. See attached photo.
