TC-24D pressure relief valve - again

[SacandagaBrad]

Back when I first bought my machine, we had several discussions regarding pressure relief valves, gearing, and the inability to deliver all the power to the ground, with plenty of technical talk on the reasons, etc. But I have to say - I was disgusted with my tractor last weekend. My neighbor and I were pulling rocks from the lawn, some in the 300# to 700# size and one that was well over 1000#. My neighbor used his 25 year old 14 HP diesel 4WD with turfs and chains, no FEL. He has an old grader tooth welded into a 3PH system that works great for popping rock out of the ground with minimal disturbance. When we were pulling on that big rock with chains, my machine wouldn't even spin the tires (turfs, no chains, on grass, FEL installed), just sat there with very little load on the motor, with the valve kicked in. Also tried pushing and lifting with the FEL, same result. I have had it checked and it is within spec, actually at the high end. So I am not getting all the power the motor has to the ground. My neighbor's 25 year old 14 HP hydrostatic drive had more pull than mine, either spinning the tires, standing it on its tail, or nearly stalling the motor while slowly spinning the tires, suggesting to me I'm not even getting 14 of my 24 HP to the ground. I understand the manufacturers have to warrantee these machines and they are going to build in safety factors so not to tear them apart, and have the safety attorneys out there making sure we don't hurt ourselves, but a gear machine would have pulled that rock sideways or at least spun the tires.

The most simple solution would have been for NH to build it with a third range on the lower end, then maybe it would get the power to the ground. Its great having a 24 hp machine in such a small package for blowing snow and mowing heavy grass, but I would be interested to know what the drawbar HP is on this model. Simple observation suggests it is far less than 14 hp, unacceptable when you are struggling to accomplish a job and need more pull, IMO.

I have always liked the machine, its design, ease of operation of the HST, and comfort. But this was very disappointing.

Brad

 

[Soundguy]

I couldn't find the DB specs for that machine online.. but would guess it is in the neighborhood of about 17 DB hp.

I'm a gear trans guy myself.. so.. I won't comment much on your fluid coupled trans... except to say.. that when i want to move something.. I like hearing the engine stall down, or something slipping vs having the machine set there and hum and have a valve open... but then.. that's just my opinion.. etc..

Soundguy

 

[SacandagaBrad]

I couldn't find the DB specs for that machine online.. but would guess it is in the neighborhood of about 17 DB hp.

I'm a gear trans guy myself.. so.. I won't comment much on your fluid coupled trans... except to say.. that when i want to move something.. I like hearing the engine stall down, or something slipping vs having the machine set there and hum and have a valve open... but then.. that's just my opinion.. etc..

Soundguy

Soundguy,

Thanks for checking. I like the HST for mowing in tight spots, loader work, clearing snow, general home owner stuff, and the obvious advantage of keeping the RPMs up and still have an infinite speed control. My knee wouldn't hold up to a clutch anymore, so gear tranny is not much of an option.

My frustration really kicked in when watching my neighbor's older machine and it occuring to me - they can build and have built a HST that doesn't lose power and just sit there "slipping". Up to that point, after numerous discussions here, I had decided I would just have to live with it as a fact of life for HST. But now it bothers me that we newer HST owners have to sacrifice power and the true potential of these machines for no apparent reason, just for the convenience of the HST.

I thought it was a NH issue, but it seems all the recent machines behave this way from what I can tell. They should redesign with lower gearing if the modern HST really needs pressure relief valves kicking out so soon. A tractor is not much of a tractor if it can't deliver the power to the ground.

Just my opinion.

Brad

 

[Soundguy]

I'd wager that there is a big difference in today's HST tractor.. and the automatics of youre.. like ford'sd 1960's ere SOS trans.. which is probably closer to a car automatic tranny than to a modern HST tranny..

Soundguy

 

[SacandagaBrad]

I'd wager that there is a big difference in today's HST tractor.. and the automatics of youre.. like ford'sd 1960's ere SOS trans.. which is probably closer to a car automatic tranny than to a modern HST tranny..

Soundguy

Well, Soundguy, I hate to point this out, but that 25 year old machine I was working along side puts it at a early to mid 80's machine I remember when anything 25 years old seemed ancient, now it seems like yesterday. On a serious note, it is a modern HST, just geared or valved differently for better performance.

We had a 1972 Case 222 garden tractor (Dad still has it and uses it all the time) that was labelled as a hydraulic drive. One difference was that you had to find the "sweet spot" on the control to provide holdback going down a hill, or it would race away on you. Everything else was similar, would slip in high range under load, but low range it has the gearing and valving to either spin or stall.

Enough complaining, I feel better now I still like my machine.

Brad

 

[Soundguy]

My point is that you have to compair apples to apples. You can't compair a machine that uses a torque converter to one that uses a pump/motor setup. EWven though they both use a fluid coupled medium for power transmission.. there are different mechanisims at work.

However, that said.... I'm not familiar with your older machine to know what type of hydro it was..

Soundguy

Well, Soundguy, I hate to point this out, but that 25 year old machine I was working along side puts it at a early to mid 80's machine I remember when anything 25 years old seemed ancient, now it seems like yesterday. On a serious note, it is a modern HST, just geared or valved differently for better performance.


Brad

 

[IH3444]

I do find it strange about some new hydro trans tractors....My friends 5 year old TC30 hydro will spin the R4 tires, and pushes fantastic, digs well with the NH 7308 FEL, then I read these post about ones that even in low, low just plain dog out. Same thing in the Kioti forum, so it's not brand specific.

 

[SacandagaBrad]

My neighbor's machine is a Bota, B6200 I believe. A work horse for sure. He never had a FEL on it, between the two of us working together, we get a lot done with two small tractors. Get him enough traction, I'll bet he would pull me backwards in a tractor pull. That's frustrating to me - not that his is capable, but that mine is not with approx 10 more HP at the motor.

My other point was to bust your chops that we (or at least me) are getting older all the time

 

[Ford850]

I might be off here, but instead of comparing the HP, shouldn't you be comparing torque? Isn't the torque the actual power to the wheels?

 

[hazmat]

Brad - time for a bigger machine...

I have a similar complaint on my TC18 - I'd always lug the engine down before spinning the tires (at least in high traction sitiuations) If I were working the loader in a pile as well, I could stall the machine.

I wonder if the HST system is the same for the TC18 & TC24D? Sounds like you have HP that is not being used.

My new B3030 will spin the tires in medium range (which is faster than L on the class 1 boomers). The sales literature indicates that they redisigned the HST for more power on the B3030 vs. the older B2910.

I wish nebraska would test the smaller tractors for drawbar pull. The only other way would be to do some sleuthing in the shop manuals to find pressure & flow specs for the HST - you can go from psi & gpm to HP with a little math.