I own a JD 3520 compact tractor with the power reverser. The machine has been at the dealer for 78 of it's 150 hour life

TJ,

All three filters have been replaced 3 times as well as the transmission fluid. The Rockshaft valve body, the loader control valve and the power reverser valve body has been rebuilt twice as well as all 4 loader cylinders. All hydraulic pressures check out normally while idling and during function operations. Everything works fine on the tractor until it is warmed up and under load. At that point the rockshaft starts hiccuping and the power reverser will slowly start failing when reversing until it quits completely. After about 1/2hr of cool down, everything will work fine again until the tractor is under load.

By the way, the hydraulic pump and return suction screen have been replaced as well. Both relief valves have been replaced and functionality verified during pressure tests.

Thx, Mike

tj,

The engine temperature is well within the normal range during failure. We did stick a Fluke thermocouple probe directly into the fill hole resivoir at the rockshaft and came up with 172 degrees Fahrenheit while the Power Reverser was in complete failure. I do not know what the temperature was at when it started losing power. Again, the power Reverser only loses power and then stops completely while going into reverse. Forward does not lose power or fail at all. I called John Deere tech services the second time that the unit failed, and was told that this temperature was well within the normal range for the John Deere Hy-Guard low-viscosity oil.

Thanks,

Mike T.

Tj,

According to the service records, The power reverser valve body has now been rebuilt twice within the last 50 hours. New oil and filters both times.

Thanks,

Mike