i have a couple questions about power shift

[careyo63]

My guess #4 Assy. Relief is sticking or #10 Valve Assy. DRV. is dirty and sticking. If it's that bad maybe worth pulling the pan and cleaning the Assy. and replace the spring if need be.

 

[jerrybob]

It's probably more like 3-5 seconds of delay, and the analogy of filling a tube to build pressure is what I pictured myself.

The fel and 3pt move instantly and the power shift delay is only for the first start of the day. The rest of the day no matter how many starts it never has the delay again.

It has fresh fluid, new filter and a clean screen.

What you have described is exactly what my 186D does......you are fine.

 

[normde2001]

I'm guessing that any delay is incorrect, and a result of fluid leak down somewhere in the transmission. Same as 3ph leakdown over time.

 

[California]

If I'm not mistaken.. doesn't the powershift has it's own pump, Separate from the engine pump ? I'll have to look at my service manual

Yes, a separate pump. But I think the intake for the transmission pump is through the same gallery of screened oil that the transmission draws from.

 

[California]

The 186 is one of the models that has the suction strainer high up in the transmission with a pick up tube. I could see where fluid would or could drain back some and require a little more time to pick up.

When I bought the second YM186D last year I opened the cover plate to check that screen, and then while I was at it I did the same on the YM186D I've had since 2009. The screen is much higher than the sump so I didn't expect to lose much oil. The first one I opened was near dry but the second one unexpectedly dumped a cup of oil when I pulled off the cover plate. I don't remember which tractor I had run recently, I just remember the mess. At least I found the screens clean. (I also replaced the hydraulic filter, the big cannister below the fuel filter, on both tractors that day).

Winston, I think you are right, that it takes a moment for pump suction to draw oil up into that screen chamber.

Hmm... I wonder if this delay to get pressure is a design feature so that cranking a cold engine with an implement raised is never working against hydraulic load. I know on the YM240 just cranking the starter will lift an implement immediately, if it had bled down slightly during a lunch break etc. Intentional design feature, or just coincidence?

 

[normde2001]

I suspect they are designed to hold pressure indefinitely same as the 3ph. I don't have powershift on my 2000B but the 3point will hold indefinitely. Have accidantally left mower raised for 6 months. Suspect prob in the valves Carey mentioned.

 

[kenmac]

I suspect they are designed to hold pressure indefinitely same as the 3ph. I don't have powershift on my 2000B but the 3point will hold indefinitely. Have accidantally left mower raised for 6 months.

Mine use to stay up... It now will leak down.. Doesn't bother me that it leaks down.. as soon as I crank it the lift raises

 

[kenmac]

well, I get on the yanmar this afternoon.. If It has any delay,, I sure can't tell it.. It's about instant when I let the clutch out