Dx-40 High/Low speed switch function?

[cpeters]

What internally does the High/Low speed switch exactly do?

I know what it does..but does it do something in the hydro system high speed bypass or is it a hydraulically activated planetary gear like some of the older tractors had.

Reason I ask is I have been traveling across a field with the switch in the high speed position and came to a ravine I needed to cross, coming to a stop. When starting again the hydrostat pressed and the engine really did not pull down but the rear tires didn't move. Obviously switching ranges it crawled right out. Is this normal or is there a planetary clutch going away or something. Obviously I know not to do that.

Question 2. Tractor is sometimes difficult to get into or out of 4wd. It seems more like the linkage is binding or something then sometimes it seems to move back an forth with ease. Even rocking the tractor back and forth seems not to make much difference. Seems more like linkage bind.

Thanks in advance.

Charlie Peters

 

[SWB]

Jinman gave the following explanation in the thread shown below:

"Re: Are there any HST's that can shift while moving? [Re: CTyler]
#804887 - 01/11/06 09:48 AM Edit Reply Quote



The Class III Boomer New Hollands (TC35/40/45DA HST "deluxe" models) all have a "rabbit-turtle" switch on the right fender and a duplicate switch on the joystick if you get the 16LA loader. This switch changes the swashplate angle in the HST's hydraulic motor between 9° and 15°. It's controlled by a solenoid and very reliable.

When you step on the HST pedal, you change the swashplate angle in the hydraulic pump, but the rabbit-turtle switch does it in the motor portion of the HST for a very dramatic and easy speed change. Approaching a pile of dirt with a loader and switching to turtle with the switch on the joystick has become so second-nature to me that I truly don't know if I could stand to be without that feature. "

As far as 4wd engagement is concerned, all of these CNH tractors seem to be a little difficult getting in and out of 4wd. It is probably not a linkage problem you are encountering but a normal indiosyncracy of the tractor. What seems to work best is to try and have the tractor moving slightly as you try and make the change.

 

[cpeters]

Thanks Jinman I was just wanted to make sure starting like that was not burning some sort of planetary clutch assy or something. I didn't have the throttle up much but I was just suprised it did not pull the motor down hardly at all and the wheels were not turning.

My 4wd might be harder than most I had at least one instance where I was actually spinning in the mud and stopped trying to rock the tractor back and forth trying to get the 4wd in I didn't think it was ever going to go in. You can feel the handle flexing when you are trying to firmly trying to apply pressure while trying to rock the tractor.

I just use the tractor for cutting my horse pastures and a few odds and ends.

For my loader work and feeding large hay bales I have a Bobcat 773G Turbo. I use it all the time....tractor just for cutting the pastures.

Thanks again for your response.

Charlie

 

[SWB]

You were probably trying too hard by rocking it back and forth. You need to finesse it a little. Try just a little throttle as you are trying to move into 4wd. Rocking it or giving it too much throttle doesn't seem to work.

 

[jinman]

</font><font color="blue" class="small">( My 4wd might be harder than most I had at least one instance where I was actually spinning in the mud and stopped trying to rock the tractor back and forth trying to get the 4wd in I didn't think it was ever going to go in. You can feel the handle flexing when you are trying to firmly trying to apply pressure while trying to rock the tractor.
)</font>

Charlie, most of us have had a problem getting our tractors to come out of 4WD, but normally it is easier to put them into 4WD. Those of us who have loaders have found shifting in/out of 4WD is very easy if we use the loader bucket to lift weight off the front wheels. Others without the FEL have had the most success using the method described by SWB. I make it a practice to go into and out of 4WD every time I start my tractor. Even though I spend most of my time in 4WD I do this just to exercise the mechanical linkage. Then, if I'm doing anything except mowing, I put my tractor into 4WD. I spend almost all my time in 4WD. I have 1030 hard-working hours on my tractor and no ill effects. /forums/images/graemlins/cool.gif

 

[SWB]

Jinman, I have a FEL on my DX35 but didn't know that trick about lifting the front wheels off the ground with the FEL before trying to shift in/out of 4wd. Thanks for the info.