Hi range HST bogging on grade - CK30 (CT230 actually)

[johnsopa]

On my used Bobcat CT230 that I just got, the HST is bogging down on our gravel driveway when in high range going uphill.

The driveway has a slightly increasing grade from 830 to 930 feet in altitude over 1000 feet of length. I guess this is about 100' of rise over 1000' of run. If I understand correctly this is a 10% (or 10:1) grade.

The tractor slows down then stops/bogs about halfway up. Medium range is OK but it still seems to bog down a bit.

I was surprised by this. Should this concern me?

I have one month of warranty left.

Thanks!

 

[krazsk]

I think you are just short of horsepower for what you are trying to do. My CT225 bogs down going uphill in high range. I figured that I was trying to haul 4000 pounds uphill with lawnmower type horsepower.

 

[ERE]

It doesn't sound strange to me. 10% is a steep grade; steeper than most mountain highway grades. My CK 25 slows down on steep grades in Hi range. I never use high except for moving form one place to another on our country roads. All my light work is in med, and anything ground engaging is Low. When it starts to slow down, just ease off on the tilting pedal. That reduces the angle of the hydraulic pump swash plate which is the hydraulic version of shifting to a lower gear. With a little practice, you wont even think about it; it will become automatic.

 

[kiotiken]

I'm planning on talking to my dealer about mine, it doesn't seem to do as well in high as it used to. I really noticed it driving over to my neighbors place a couple weeks ago. There is a slight, and I mean slight, incline on the paved road, and I had a hard time getting any speed, it started really bogging down. I have driven 4-5 km in the past and gone up some pretty big hills in high and I'm thinking it's bogging down a lot more now, and on less of an incline.

On top of the CK30 and FEL, I also have loaded tires, a 1200 lbs backhoe and a cab. The dealer says the set up is about 6500lbs, I asked because I want to get a trailer to be able to move it around.

 

[johnsopa]

Thanks for the replies everyone. I should mention that the only attachment I have is a FEL. No ballast yet, nothing on the back when I was testing this out. I do have a 60" rotary mower but haven't driven the driveway with it attached yet.

I think I'll ask the Bobcat dealer what he thinks when I stop in to get filters.

 

[kiotiken]

Thanks for the replies everyone. I should mention that the only attachment I have is a FEL. No ballast yet, nothing on the back when I was testing this out. I do have a 60" rotary mower but haven't driven the driveway with it attached yet.

I think I'll ask the Bobcat dealer what he thinks when I stop in to get filters.

Please update this thread when you do, I'd like to hear other dealers opinions. I'll let you know what my dealer says.

 

[Mousefield]

Seems normal to me. I don't often use high gear on my CK35 HST. There is one part of our road with a bit of a grade and I do notice it slowing down if I am in high gear. I use mid range about 99.8% of the time. Just remember, how well would your car/truck do with only a 30HP motor.

 

[SPYDERLK]

I'm planning on talking to my dealer about mine, it doesn't seem to do as well in high as it used to. I really noticed it driving over to my neighbors place a couple weeks ago. There is a slight, and I mean slight, incline on the paved road, and I had a hard time getting any speed, it started really bogging down. I have driven 4-5 km in the past and gone up some pretty big hills in high and I'm thinking it's bogging down a lot more now, and on less of an incline.

On top of the CK30 and FEL, I also have loaded tires, a 1200 lbs backhoe and a cab. The dealer says the set up is about 6500lbs, I asked because I want to get a trailer to be able to move it around.

Could it be you were in 4wd? Thatll add extra load and be real noticeable in Hi. ... or - Were the tires always loaded. Could you be making a before and after comparison?
larry

 

[kiotiken]

Could it be you were in 4wd? Thatll add extra load and be real noticeable in Hi. ... or - Were the tires always loaded. Could you be making a before and after comparison?
larry

Good point, it was in 4wd, but I've never taken the tractor out of 4wd, so it was the same as before. The only differences this time is the kioti cab that I've added (350 lbs I think they say) and I had pallet forks on the front which is probably an extra 50-100 lbs over the bucket.

Until I got over the grade, I couldn't get up to even mid range speed. I did come off the pedal to stop it from bogging and give it a fighting chance, moved the throttle to wide open and gently tried to pick up speed, but no go.

 

[johnsopa]

Please update this thread when you do, I'd like to hear other dealers opinions. I'll let you know what my dealer says.

Stopped by the local Bobcat dealer. The dealer believes this is acceptable as a 1:10 is relatively steep and hi range is designed for flat level travel.

I'm going to be adding 30 or so gallons of Rim Guard to each tire sometime this week, so I hope I don't lose mid-range on the driveway now that I'll have even more weight in the back.

 

[MotorSeven]

John, my driveway gains 200 feet over 1/3 of a mile. I always climb and go back down in 4wd(you need that 4 wheel engine braking going downhill, especially with a load/trailer) and medium gear. My rears are loaded and most of the time I have a box on it and in 2wd it will climb, but they do spin a bit. I run at max rpm(DK40 is just under 2500). I also remember on my CK30, putting the rpm on the small red hash mark on the gauge(HST loves max rpm). High range ain't gonna cut it on a 10% grade with any HST that I have driven.

 

[LaVoie Equipment]

Everybody. All of these hydro tractors require Engine RPM's for the hydrostatics to maintain speed.

Try this. Instead of holding the HST Pedal to the mat as you are doing; as you sense/feel/hear or better yet see the Engine RPM's dropping, easily lift pressure (your foot) off HST pedal and you will see the Engine RPM increase, tractor speed will not decrease as fast. You are putting the engine back into it's power band. This works from your Sears lawn mower to your zero turn mower to even a DK50SE 50hp tractor. Yes, you can hydraulically bog down even 50 hp with to much load.

And for you gear tractor owners, you are correct, you drop a gear to get the RPM's back up. Pulls better too..

Tony

Tony

 

[mx5guy]

CK 27 HST, H is for down hill or flat terrain, for all HST with H / M / L range, not so sure about some of the larger horse powered DK's but CK series for sure. But I am in a hilly rocky area and in 4 x4 and low or Med range all the time.

 

[Canada_CT230]

Normal....I have a CT230. HI range is for level road travel only. You don't start your truck and trailer towing in 5th gear.

If you want to go fast...don't use a tractor!

 

[johnsopa]

I see several of you have commented that you leave 4x4 mode on all the time. This surprises me especially since I can feel the drivetrain binding when turning sharply. As with cars/trucks in 4x4 mode, it seems to me that 4x4 mode in the tractor should only be used when needed.

Am I incorrect in this understanding? Is the 4x4 mode on our tractors more like what's in my Subaru (AWD) that can be used 100% of the time with no ill effect?

 

[VictorW]

You're right. It's 4WD and not AWD. Use the 4x4 only when you need the traction. If on hard ground, it will bind especially when turning sharp because the front and rear tires are travelling over the ground at a different rate. If the 4WD shifter seems a little stiff, lube the linkage and especially where the rod shaft enters the trans case. I use white spray lithium.

Try what Tony, from LaVoie Equip, advised. If the hill is very steep, rpms should be 2500-2600 and ease up on the pedel some. If it still won't go, then you'll have to use medium range. When I have my KB2375 bh on, about 700lbs, I can tell that it's there. The guys from Michigan Iron & Equip had advised before that the hst likes 2000rpm to work properly. If you were just putting around slowly on the level, you could be around 1500rpm but if you want the tractor to do some work, it's 2000 and up.

 

[kiotiken]

Everybody. All of these hydro tractors require Engine RPM's for the hydrostatics to maintain speed.

Try this. Instead of holding the HST Pedal to the mat as you are doing; as you sense/feel/hear or better yet see the Engine RPM's dropping, easily lift pressure (your foot) off HST pedal and you will see the Engine RPM increase, tractor speed will not decrease as fast. You are putting the engine back into it's power band. This works from your Sears lawn mower to your zero turn mower to even a DK50SE 50hp tractor. Yes, you can hydraulically bog down even 50 hp with to much load.

And for you gear tractor owners, you are correct, you drop a gear to get the RPM's back up. Pulls better too..

Tony

Tony

My recent experience that concerns me a little is that the (paved) road was at a very slight incline, although an incline that continued a long way, and that even at full throttle and easing off the pedal, I never managed to get moving any faster than I could have gone in mid range. As soon as I give it more petal, it would start to bog and there would be no increase in speed, this was done very gradually. I tried to keep the rpm's at the 2500 level marker by increasing or decreasing the amount of pedal.

 

[MotorSeven]

I didn't address easing off the pedal on a 10% grade since if still in high gear it won't make a bit of difference. I will say that in Mid range I even set cruise control all the way up to the house...no feathering required.

I do need to do an actual calculation of my grade....I bet it is around 20% or better in places.

 

[LaVoie Equipment]

My recent experience that concerns me a little is that the (paved) road was at a very slight incline, although an incline that continued a long way, and that even at full throttle and easing off the pedal, I never managed to get moving any faster than I could have gone in mid range. As soon as I give it more petal, it would start to bog and there would be no increase in speed, this was done very gradually. I tried to keep the rpm's at the 2500 level marker by increasing or decreasing the amount of pedal.

I am doing this from my phone - what hp do you have? What is your tractor optioned with?

Remember, A lot of things come into play.

Tony

 

[VictorW]

My recent experience that concerns me a little is that the (paved) road was at a very slight incline, although an incline that continued a long way, and that even at full throttle and easing off the pedal, I never managed to get moving any faster than I could have gone in mid range. As soon as I give it more petal, it would start to bog and there would be no increase in speed, this was done very gradually. I tried to keep the rpm's at the 2500 level marker by increasing or decreasing the amount of pedal.

From your above mention that it is a CK30hst with 1200lb bh, loaded tires. and cab with total weight at @6500lbs, that's a load for those 30 ponies. Hopefully Tony can give you an idea of what it may be being that you said it used to do better.