How hot is the diff area supposed to get?

N80 · Jun 5, 2006

This weekend I was mowing with my L4400 and JD LX6 rotary cutter. I mowed for about an hour and a half, raised the mower and drove back to my cabin. The drive is probably 1/2 mile with half of it unpaved field/woods road and the other half bumpy country blacktop.

When I got back I began to rinse the tractor off as I usually do when its dusty. (I usually let the tractor cool and never spray cold water on a hot engine). This time the tractor was still hot and after spraying the rear of the tractor I noticed steam coming up off of the rear diff/3pt hitch area, specifically from where the lift arms attach. This area dried more quickly too. I put my hand on it immediately and it was hot but not too hot to hold my hand on it.

Prior to and after this the tractor is functioning properly in every way. Hydraulic/tranny fluid is new and the level is appropriate. Hydraulics and PTO working fine.

This may not be an issue but I just never noticed it before. I was wondering if a position control 3pt hitch has to 'work' when a heavy mower is in the raised position and bouncing down the road? It was a warm day, but not too bad, about 86.

N80 · Jun 5, 2006

This weekend I was mowing with my L4400 and JD LX6 rotary cutter. I mowed for about an hour and a half, raised the mower and drove back to my cabin. The drive is probably 1/2 mile with half of it unpaved field/woods road and the other half bumpy country blacktop.

When I got back I began to rinse the tractor off as I usually do when its dusty. (I usually let the tractor cool and never spray cold water on a hot engine). This time the tractor was still hot and after spraying the rear of the tractor I noticed steam coming up off of the rear diff/3pt hitch area, specifically from where the lift arms attach. This area dried more quickly too. I put my hand on it immediately and it was hot but not too hot to hold my hand on it.

Prior to and after this the tractor is functioning properly in every way. Hydraulic/tranny fluid is new and the level is appropriate. Hydraulics and PTO working fine.

This may not be an issue but I just never noticed it before. I was wondering if a position control 3pt hitch has to 'work' when a heavy mower is in the raised position and bouncing down the road? It was a warm day, but not too bad, about 86.

Bird · Jun 5, 2006

George, this topic comes up from time to time. I wondered about it myself when I was a new owner. It's "normal" for the hydraulic oil to reach 100 degrees above the ambient temperature. So with our 90+ temperature, that's some hot oil and metal. If you'd tried it before spraying it with cold water, you probably cold not have kept your hand on it. But, personally, I'd be careful about spraying cold water on not metal, and apparently you are, also.

Bird · Jun 5, 2006

George, this topic comes up from time to time. I wondered about it myself when I was a new owner. It's "normal" for the hydraulic oil to reach 100 degrees above the ambient temperature. So with our 90+ temperature, that's some hot oil and metal. If you'd tried it before spraying it with cold water, you probably cold not have kept your hand on it. But, personally, I'd be careful about spraying cold water on not metal, and apparently you are, also.

N80 · Jun 5, 2006

Thanks Bird. When I asked my B-I-L farmer, a man of few words, he just said 'those things get pretty hot'. I guess I'd just never really noticed but I think from now on I'll keep cold water off the entire tractor until it has cooled down.

N80 · Jun 5, 2006

Thanks Bird. When I asked my B-I-L farmer, a man of few words, he just said 'those things get pretty hot'. I guess I'd just never really noticed but I think from now on I'll keep cold water off the entire tractor until it has cooled down.

Mike_Lipke · Jun 5, 2006

The hydraulic pump that is pumping all the oil to run the mower is making the oil hot. Some of that oil also goes to the rear end, and it gets hot as well, but not because it is doing that much work making the tractor move. Most of the work and heat is generated by the pump spinning the blades.
If you were plowing, it would get hot as well, but because the pump is working against the wheels and the ground. They are made to get hot, which is why they specify changing the oil every so often.

Mike_Lipke · Jun 5, 2006

The hydraulic pump that is pumping all the oil to run the mower is making the oil hot. Some of that oil also goes to the rear end, and it gets hot as well, but not because it is doing that much work making the tractor move. Most of the work and heat is generated by the pump spinning the blades.
If you were plowing, it would get hot as well, but because the pump is working against the wheels and the ground. They are made to get hot, which is why they specify changing the oil every so often.

Bird · Jun 5, 2006

George, when I was concerned about how how the hydraulics got, I talked to one dealer who said, "We never worry about it unless it gets hot enough to discolor the paint." /forums/images/graemlins/shocked.gif It seems to me that you might be a bit concerned before then. /forums/images/graemlins/tongue.gif Anyway, I inserted a temperature probe into the dipstick hole on mine a few times and verified that about 100 over ambient temperature was about what to expect.

Bird · Jun 5, 2006

George, when I was concerned about how how the hydraulics got, I talked to one dealer who said, "We never worry about it unless it gets hot enough to discolor the paint." /forums/images/graemlins/shocked.gif It seems to me that you might be a bit concerned before then. /forums/images/graemlins/tongue.gif Anyway, I inserted a temperature probe into the dipstick hole on mine a few times and verified that about 100 over ambient temperature was about what to expect.