Oil & Fuel Hdyraulic/trans oil change improved performance

[jimgerken]

Recently my 2009 3720 hit the 200 hour mark. It did some pretty serious loader work this summer and was used for ground-engaging work too, pulling a ten foot disk. I felt it was time for the trans/hyd oil change. There were some symptoms that I had noted that it had since new, which I will list for you. Settling: Loader, 3-point and especially the hyd top link would settle quite fast. Top link would fully extend in a couple hours with warm fluid. And 3-point would settle overnight if forgotten up (750 pound load). Air ? - There was an annoying symptom where when lifting the loader the first few times each day it would stumble a few times as if there was air being pumped into the system. And the steering had the same effect, making noise and stuttering. I reasoned that if there was air in both systems, it had to be pulled into the pumps on the suction side, which is common between the steering and implement pumps. So I carefully inspected the suction line and fittings. Nothing jumped out at me.
Looked in the manual, the chart showed to use Low-Viscosity if using tractor below 0 or so. And use of standard viscosity JD fluid was allowed for above 0, and of course was proper for temps over 100 (hopefully I got those numbers about right). Anyway, I opted for standard JD oil, not lo-vis.
Changing the oil is time-consuming 'cause I gotta dump the drain pan about five times during draining, and there is the big sump filter to remove. The manual says replace it. I looked at it, the thing is a mint assembly of stainless screen and plastic and sure looks reuseable to me. I looked at it under a magnifier light and found three little machining scraps in it, which I carefully flicked out. I re-installed the original filter in the sump. Then cleaned the two screens in-lines (which had next to nothing on them), one in the power beyond tubing, and one in the power steering circuit. Reassembled and dumped in 7.5 gallons of new oil.
After operating everything several times to get the air out, I checked, added a bit more, and had fluid right at top cold mark.
Next two days I used tractor to log. Lifted and hauled out of woods 4-5 cords of wood in 7 foot pieces. Made a heck of a stack. Also moved a stump with dirt that I would not have believed it could lift.
So far, no more air noise in steering or implement side. And the lifting power seems better, and the settling is much less. It might be my imagination, but the hydraulics seem to whine just a little bit louder than before, which is not bad and is almost gone when everything is warmed up.

 

[WH401]

Recently my 2009 3720 hit the 200 hour mark. It did some pretty serious loader work this summer and was used for ground-engaging work too, pulling a ten foot disk. I felt it was time for the trans/hyd oil change. There were some symptoms that I had noted that it had since new, which I will list for you. Settling: Loader, 3-point and especially the hyd top link would settle quite fast. Top link would fully extend in a couple hours with warm fluid. And 3-point would settle overnight if forgotten up (750 pound load). Air ? - There was an annoying symptom where when lifting the loader the first few times each day it would stumble a few times as if there was air being pumped into the system. And the steering had the same effect, making noise and stuttering. I reasoned that if there was air in both systems, it had to be pulled into the pumps on the suction side, which is common between the steering and implement pumps. So I carefully inspected the suction line and fittings. Nothing jumped out at me.
Looked in the manual, the chart showed to use Low-Viscosity if using tractor below 0 or so. And use of standard viscosity JD fluid was allowed for above 0, and of course was proper for temps over 100 (hopefully I got those numbers about right). Anyway, I opted for standard JD oil, not lo-vis.
Changing the oil is time-consuming 'cause I gotta dump the drain pan about five times during draining, and there is the big sump filter to remove. The manual says replace it. I looked at it, the thing is a mint assembly of stainless screen and plastic and sure looks reuseable to me. I looked at it under a magnifier light and found three little machining scraps in it, which I carefully flicked out. I re-installed the original filter in the sump. Then cleaned the two screens in-lines (which had next to nothing on them), one in the power beyond tubing, and one in the power steering circuit. Reassembled and dumped in 7.5 gallons of new oil.
After operating everything several times to get the air out, I checked, added a bit more, and had fluid right at top cold mark.
Next two days I used tractor to log. Lifted and hauled out of woods 4-5 cords of wood in 7 foot pieces. Made a heck of a stack. Also moved a stump with dirt that I would not have believed it could lift.
So far, no more air noise in steering or implement side. And the lifting power seems better, and the settling is much less. It might be my imagination, but the hydraulics seem to whine just a little bit louder than before, which is not bad and is almost gone when everything is warmed up.

I was having the same issue on my 3320, the loader would sound like there was air in the cylinders in the first few minutes after start up. I changed the hydro fluid in September and it still does it to a degree, so I'm not too worried about it.

On whether to choose regular or low-viscosity Hygard, for the climate you encounter I would have gone with the low-viscosity. The reason that your hearing an increased whine is because regular Hygard doesn't flow as good at LV Hygard when it's cold. Some manuals state the LV Hygard is only good to below 100 degrees, others I have read say it's good to over 100 degrees. I know I see a couple 100 degree temperature days here, but I wouldn't be outside on the tractor on those days anyway. That said, I replaced the old fluid with LV Hygard, and notice a more responsive loader, easier to shift gears, and reduce gear whine in general.

On a side note, did you change the front axle oil as well? If not you really should think about doing that. Many owners have found metal shavings in the front axle left over from the casting process, you don't want them running around in there.

 

[jimgerken]

I was having the same issue on my 3320, the loader would sound like there was air in the cylinders in the first few minutes after start up. I changed the hydro fluid in September and it still does it to a degree, so I'm not too worried about it.

On whether to choose regular or low-viscosity Hygard, for the climate you encounter I would have gone with the low-viscosity. The reason that your hearing an increased whine is because regular Hygard doesn't flow as good at LV Hygard when it's cold. Some manuals state the LV Hygard is only good to below 100 degrees, others I have read say it's good to over 100 degrees. I know I see a couple 100 degree temperature days here, but I wouldn't be outside on the tractor on those days anyway. That said, I replaced the old fluid with LV Hygard, and notice a more responsive loader, easier to shift gears, and reduce gear whine in general.

On a side note, did you change the front axle oil as well? If not you really should think about doing that. Many owners have found metal shavings in the front axle left over from the casting process, you don't want them running around in there.

My climate: well, the tractor stays in a 45 degree F heated shop all winter. It goes out to blow snow, but is running all the while and the oil gets warmer from there. If I was going to store it in Minnesota ambient conditions, I would definitely use the LV. 100 degree days are a real probability for it. And it will be working hard at times, pulling a load, and doing heavy loader work.

I did not change the front end oil yet, but good suggestion. I was putting it off 'cause there was a leak in it from day one and after 160 hours (three months) I finally got it hauled in and repaired by the dealer. During that 3 months I poured six quarts thru it. And I assume they had to change the oil when they had it apart to do the front seal. But I will change it now anyway, thanks.