Going up a steep slope in my new (to me) JD955

[onthehill]

Ok, so I guess I should start this with the fact that I recently bought a new (to me) JD955. Everything is going great with the tractor so far...boy, a lot to learn over the Craftsman lawn tractor I've been using for years. I do have a question though. On our property, I have a very steep/long hill. This weekend I thought I'd give it a go going up the hill. So, what I did was put the tractor in low and engaged the MFWD. I slowly started up the hill and got about 3/4 of the way up and then the tractor stopped moving forward (the engine didn't hestitate or anything, it just stopped moving forward). The harder I pushed the forward pedal, I got a louder whine but not further forward. So, I backed down the hill and tried it without the MFWD. The tractor made it all the way up the hill (slowly). I thought I might not make it, but I did. I've also learned that I can't go up any hills if it's in high gear but I'm figuring that's pretty typical.

So, my question is, is that normal? I wouldn't have though that the MFWD would have had a negative impact on the climbing ability. I've read a bunch of posts online that talk about problems going up hills due to the pump not being able to pump due to the slope (or something like that). What do you guys think? What am I doing wrong? Would backing up the hill work better?

I'm totally new to this so I'm open to any input. Thanks in advance!


Bob

 

[beenthere]

:welcome:
Haven't been reading about problems with the pump not pumping going up hills.
I'd try the backing up idea, in mfwd just to check out that pump thought.

I've no problem with my HST JD 4300 going up steep hills, and no difference that I can tell if in front wheel assist or not.

Interesting problem.

 

[dklistul]

Low on hydrastic fluid? I know nothing of HST tractors but if your transmission oil level is low, maybe the pickup is being uncovered on a steep hill.

Just the airplane mechanic in me thinking with my fingertips. . .

 

[mjncad]

Welcome.

If that 955 has a HST, it sounds like you are in High Range, which is essentially for transport.

What kind of tires do you have on it? What kind of ground (e.g. dry dirt, mud, grass, brush, etc) were you trying to climb?

Depending on the slope's angle, I'd back up the hill for safety. Going up the hill in forward will make the tractor want to flip backwards as shown at: http://www.tractorbynet.com/forums/safety/169207-idiocy-surviving-chance.html

 

[RoyJackson]

The harder I pushed the forward pedal, I got a louder whine but not further forward.

Bob

I'm no hydro guy, but I think you'll want less pressure on that foward pedal.

 

[kennyd]

I'm no hydro guy, but I think you'll want less pressure on that foward pedal.

Exactly, 100% correct as usual Roy


Welcome to TBN Bob

HST's are "infinatly variable". The tendancy for new operators is to push the pedal harder when they encounter resistance-more power right? But, that effectivaly put's the tranny into a higher gear causing exactly the problems you had. What you need to do is to let up on the pedal to get "more power".

You did not mention what RPM's you where operating at, but you need to keep them up for good flow, And also low range as already mentioned.

 

[thetooth]

you may be a little low on fluid and the angle of the tractor on the incline exaggerated the low fluid.

 

[onthehill]

Thanks for all the info everybody! Yes, the tractor does have HST. I'll have to check the fluid and see if that helps. Supposedly the dealer serviced the tractor before I took delivery so the fluid should be full but you never know. As far as what RPM I was at...I'm not sure what the RPMs were reading but I had the tractor at full throttle.

kennyd...yes, I was definitely making that mistake. I guess I was figuring it was like a car...push the accelerator down harder as you go up a hill.


Bob

 

[Acehardly]

If the fluid isn't low, you need to go back to the dealer. I can't imagine my 955 slowing down for any hill in low unless I was towing an anchor. How big was this hill anyways?
Tony

 

[JD755]

There definitely is a problem. I can mow up the back side of my dam and my much lower horsepower 755 never slows down.

 

[onthehill]

It's a pretty steep rise. I haven't measured it yet (new property hence the new tractor) but, it's about 150' long and at about 40% of rise.

I'm hoping it's just the fluid. I'll stop over there and check it out later this week.

 

[RoyJackson]

There definitely is a problem. I can mow up the back side of my dam and my much lower horsepower 755 never slows down.

Might be, JD...but I think it's a technique problem (stomp down on the pedal)...let's see how he does with a little less pressure (and maybe a lower range selection).

It's a pretty steep rise. I haven't measured it yet (new property hence the new tractor) but, it's about 150' long and at about 40% of rise.

That's a low range slope. If you have three ranges (can't recall, but I think the 955 does), you might try the middle range ("B"?). Just don't flatten out the foward pedal...

 

[onthehill]

Thanks Roy. The 955 only has a 2 ranges (lo,high). I'll check the fluid level and ease up on the pedal. Thanks again for all the help.

I see you're in PA. Anywhere near Pittsburgh? I'm just north of Pgh.

 

[RoyJackson]

I see you're in PA. Anywhere near Pittsburgh? I'm just north of Pgh.

No...about 3-4 hours east outside York (south central).
Hope that lower range and less pressure on the pedal works for you. Gotta admit, less pressure on the pedal when you want more power is counter-intuitive. Guess that's why I prefer gears...

 

[kennyd]

Gotta admit, less pressure on the pedal when you want more power is counter-intuitive. Guess that's why I prefer gears...

That's because you are thinking of it as a accelerator pedal, which it is not. One must think of it as a "infinitely adjustable gear shift" so less pedal is a lower gear.

Clear as mud?

 

[KubieTwo]

kennyd...yes, I was definitely making that mistake. I guess I was figuring it was like a car...push the accelerator down harder as you go up a hill.


Bob[/QUOTE]

Listen to kennyd. The harder you press the pedal, the more fluid volume you are asking the pump to send to the hydraulic motor but what you really need is less volume and more pressure (pushes harder). The net result of your action is the exact opposite of the requirement. This is the nature of HST and you need to learn to operate it for what it is...NOT AN AUTOMATIC TRANSMISSION like a car, and what you are pushing is not an accelerator. You have nothing wrong with you tractor IMHO but a bit wrong with technique. If the engine rpm's are dropping, back off on the pedal. If you are in H range and you continue dropping rpm and speed, you may need to select L and use the same technique. Push as hard as you want but when you start losing rpm, back off. The faster you stop trying to operate it as a car the faster you will learn how to make your tractor work for you. Good luck, have fun, and enjoy.

 

[onthehill]

Thanks guys! Boy, lots to learn.


Bob

 

[RedHawkRidge]

I had a 955 and used it to mow steep hilly fields all the time, and never had problems with climbing while dragging a 272 rear finish mower. I loved that tractor and wish I'd have kept it.
You have an issue -- don't know what's going on, but you shouldn't have the unit lose power when you push on the pedal.
jim

 

[jbarker855]

I think KubieTwo and Kenny d are exactly right.
My 855 runs excellent. Well maintained. Lots of power. But if I try going up a steep hill in high gear at a fast speed, the engine speed drops down and I have to back off the HST pedal to keep the engine from lugging. It has been acting the same way for 3 years (since I've owned it), with no worsening of this "problem". It is not a problem, just the way it is. You can't ask a 24 hp tractor to go up a steep hill at a high rate of speed without bogging the engine down. You will be fine.
-Jay

 

[onthehill]

Well, it looks like you guys were right. I checked the hydro fluid over the weekend and it was full. So I took the hill again. This time, I just pushed the pedal down a little bit and the tractor chugged up the hill. The engine RPMs never dropped, it just slowly climbed up the hill. Next time I'll have to try pushing the pedal just a little bit further.

Although, I did find out that my fuel gauge doesn't work. Don't ask me how I found that out. I was also very happy to find that the previous owner/dealer painted the engine and painted the fuel bleed screws in place. I'm going to have to figure out how to break those suckers loose.

Thanks again for all the help. I have a feeling that I'll be spending a lot of time trolling this site.


Bob