L3710 HST whine.

Darren · Oct 10, 2011

I haven't noticed the whine before. The tractor has been parked for over a year. Yesterday I put a battery in and it started fine. I didn't run it much yesterday. Today I bushhogged for about an hour and I noticed a high pitched whine that's new to me. The higher the RPM the louder the whine.

I ran the tractor in low the whole time since I was on a hill. I checked the hydraulic oil and thought it might be a bit low. When I unscrewed the cap on the rear, the transmission was pressurized. There's was a big poof of air when the cap came off. I added a bit more than a quart. The oil in the sight glass was where it should be. There's no evidence of leaks. The tractor just rolled 500 hrs.

I can't find my operators manual. I know there is an adjustment on the right side (looking forward) that needs to be rotated 90 degrees depending on whether the loader is on or off. The loader is currently off the machine. Should that slot run up and down or sideways with the loader removed.? Any other ideas? The whine seems too loud for normal operating noise.

Singlemalt · Oct 11, 2011

Never had the loader off when I had my L 3710 but I do recall the valve lever. On the right side in against the engine if memory serves.

Perhaps it was never changed when the loader was removed.

Never experience pressurization when the filler cap was removed. The L 3710 takes a fair bit off TCH so adding a quart doesn't sound like much.

Was there oil in the sight glass before you added some?
Is the whine there all the time or just when the bushhogg (PTO) is engaged or just when the tractor is moving?

Darren · Oct 11, 2011

I only get the whine when I run it over 2000 rpm. there was fluid in the cight glass before I added more. If you have an operator's manual do you mind looking up the valve setting. There's a drawing that shows the alignment.