Attacking that power problem CT225

[bbse]

Two things

1. I may have a weak relief valve but I figured out how to get up that hill in mid range. I hit it at a angle, not quite 45 degrees, probably more like 30 or so. I am talking about side to side now. I guess that takes some of the up angle out as I can go right up it like that. Luckily, with loaded tires it is still very stable.

2. I hauled it down to west TN to work on some property down there. It is very flat. I can see where someone not dealing with steep hills would not notice the relief valve issue. I have a few tractor length banks but I went right up them loaded with no problem.

Haven't heard back from the service manager, doubt if I will. I will have to start calling I guess. Anyways, I think this thread is about done. As soon as I have new info I will start a new thread.

 

[dfkrug]

From my research, the CT235 does have a different relief valve than the CT225/230.

How did you find that out? What is the spec for the RVs on the CT235 HST?

A dealer could look up the part #s for 2 different M27 tractors, but he
would not have the pressure setting unless he looked it up in a service
manual. If someone had a Bobcat parts book, it may cover all 3 models in
the same book, like my Kioti CK25/30 parts book does for 2 models. It could
tell you if the part numbers ar different, but not the specs.

If indeed the HST RVs are set higher for the CT235, I have no doubt you
could put one in other M27s. Getting one just for Forward would be enough.
I would do it.

 

[bbse]

Someone emailed me a parts breakdown list for the 225/230 vs the 235. The part numbers were different but your right, pressures were not listed so I do not know those numbers.

 

[SPYDERLK]

From my research, the CT235 does have a different relief valve than the CT225/230.

How did you find that out? What is the spec for the RVs on the CT235 HST?

Probably followed up on post #65 ....
larry

 

[MtnViewRanch]

Just thought that I would post some more info for you guys to compare. I have a Mahindra 3215HST. Supposed to have 32hp, dealer says that they usually dyno out at 34hp. :thumbsup: My tractor has all tires filled, weight with loader and box blade is right around 5000lbs.

I put my bucket into a large pile of dirt so that the tractor would not move forward.

I first checked to see if the tires would spin at 1500rpm. Low range spun no problem. Mid range would not spin the tires, just loaded the motor. High range was the same, just loaded the motor.

Then I raised the rpm up to 2000. Low range spun the tires, mid range spun the tires, high range would not spin the tires, just loaded the motor.

The last rpm range that I checked was 2500. I very seldom run the tractor at this rpm, but went ahead and checked it. All the same results as at 2000rpm.

I have looked at my service manual, and the relief valve for my tractor is supposed to be set at 4974psi at 50*C. Based on how my 3215HST performs and the what seems like low RV setting is, my guess is that these smaller tractors have a lower RV setting. My tractor performs very well in all ranges. Now for the most part I only use high range for transport, but it has no problem going up hill without any noticeable slowing.

Just thought that I would share some info from another brand so that you would have some more references to compare too.

 

[dfkrug]

I have looked at my service manual, and the relief valve for my tractor is supposed to be set at 4974psi at 50*C. Based on how my 3215HST performs and the what seems like low RV setting is, my guess is that these smaller tractors have a lower RV setting.

That is an interesting test, Brian. Mahindra no doubt uses lower gearing.

In the HST issue with the DaeDong tractors, one could argue that the
designers chose either a too-low RV pressure, OR too-tall gearing. Or both.
The best comparison is two tractors where the only difference was the
engine....can both spin tires in LOW?

 

[MESSMAKER]

That is an interesting test, Brian. Mahindra no doubt uses lower gearing.

In the HST issue with the DaeDong tractors, one could argue that the
designers chose either a too-low RV pressure, OR too-tall gearing. Or both.
The best comparison is two tractors where the only difference was the
engine....can both spin tires in LOW?

It has a 13mph top speed in high. hard to believe it is too high geared.

 

[MtnViewRanch]

It has a 13mph top speed in high. hard to believe it is too high geared.

The 3215HST has a top speed of 11.3mph with 27x8.5-15 / 15x19.5 industrial tires. I think that the BCs have the same size tires. Can someone confirm tire sizes? That would put the BCs at a 15% higher gearing.

More things to ponder.

It looks like the rears are the same and the fronts are on 14" rims 27x8.5-14.

 

[bbse]

The forward speed for the Kioti CK27/30/35 HST with AG's is 13.07. I think it should be the same as a CT225/230/235. The size listed is (Ind1 4WD- Rear 15x19.5). Now the other day I seem to remember seeing that with R4's were running 11 MPH instead of 13 MPH. I remember thinking that I thought Ag's should have been slower as I thought they were shorter....but since I can't find it I may just have a faulty memory.

Link to Kioti

KIOTI - run ahead of the pack!

Link to CK27 HST PDF

http://www.kiotitractor.com/attach_files/Products/CK Series Catalog 05-2009(3).pdf

 

[dfkrug]

It has a 13mph top speed in high. hard to believe it is too high geared.

The total gear ratio in LOW range will determine if the engine can deliver
enough force to the tires in order to spin them. If the HST is constrained
to a pressure of 5000psi max, then the gear ratio needs to be lower in
order to spin the tires in a hi traction situation. The 3215 does what I
would expect a properly designed HST tractor would do.

My Bobcat had the 11.2-24 R1 tires, and it would have higher traction, but
taller gearing (diameter) vs my CK30 that has 15-19.5 R4s. As I said
earlier, both can be put into situations where they can not spin tires in LOW.
IMO, that is a design mistake in either RV pressure or LOW range gear ratio
(or both).