HST Power Loss on Kubota Grand L3940 HST+

[Dead Horse]

you sure you don't have a quick connect not fully engaged and are not loading up the HYD pump.

Seen it before..............

 

[ericher69]

Any updates?

 

[RobK]

Hello Guys... Remaining Frustrated as I'm back with no real progress to report on this issue IMO...
After taking my L3940 to the dealer yet again and asking them to check the HST+ specifically, they reported the HP reading at the PTO is right where it should be and that the HST+ trans seemed "normal" to them. I ask if they could check the pressures in the HST+ as I wanted to be sure that there wasn't damage or defect in the trans pump, etc... they didn't indicate anything was wrong and simply said that I had the settings on the HST+ out of whack and shouldn't use the HST+ features when tilling, etc. Not acceptable, IMO...

Recently during spring planting season, we tried to use this 3940 with a 6' tiller... it cuts deeply into the hard, clay soil great with no rpm loss when standing still..., but as soon as you begin to creep forward in LOW/LOW(turtle), the rpm's die and you must lift the 3pt. to a very shallow depth inching slowly to keep it from loading the engine and dying as you move forward... I know that this machine had MUCH more power under load and motion when it was newer... it only has ~ 440 hours on it now. No general fuel, filter or engine performance issues/dealer maintained.

For a better background as to what may be the issue: I hired a son(21) of a friend as a "helper" two years ago and showed him the ropes working with me during that spring/summer.... he did ok under supervision working with me. The following year, I got him started and then checked in with him weekly(I'm 6 hrs. away) as he worked on the farm to plow, till and plant corn, beans, clover, etc. in fields and food plots and then dress the woods roads, etc.
I've since fired him after discovering many lies including not working hours as claimed and waiting until just before I got there to rip around trying to get everything done/mowed from weeks of doing nothing. I found that all of my implements used with this tractor were bent, broken and abused... he was turning with this tractor and implements still in the ground and I suspect that he severely overloaded the trans in too high a gear/range during that season of abuse.

If I can ask of someone here...
What components should be checked/repaired/replaced in the Hydraulics or HST+ that would have been damaged by this type of abuse and cause this power loss during forward/back movement?

I'm actually to the point where I'm going to trade this machine in on a L5240 or a used L in higher HP to be able to do the work I need to...
Is it reasonable to expect that an L3940 should be able to handle a 6' rototiller in the clay soils of SE Ohio??

Thanks so much for your help on this perplexing problem... I love my Kubotas and don't fault the machine although this is getting very frustrating. This is my last shot before getting rid of it and going to something in the 50 HP range... I appreciate anyone's suggestions.
Thanks, Rob

 

[PHILIP8N]

I have used a 6' Woods tiller in medium to hard clay ground in central Indiana several times in virgin land and ex-farm fields. I also run low/low creep speed with cruise control to make a nice seed bed with one pass, or to break up ground to remove dirt with FEL for driveway installation prep. I had no horsepower issues, pleanty of reserve. If I hit a root or rock, the shear pin would break on the tiller. Philip.

 

[DieselMonk]

I just got done reading the whole thread. You have a power issue of some sort. Either the engine isn't getting enough air, or fuel to make power, or something is taking a lot of power away. A broken HST would whine like a bugger and you wouldn't be moving good at all and doing nothing to take extra power away from the engine. To me you have a power making problem. Your dealer isn't giving you any hard evidence printout either. Just some sales rep one size fits all answer. Is the engine black smoking while dying or just dying with clear exhaust gasses? If it is clear, you have some fuel delivery issues of some sort.

If you are anyways near on considdering trading in the tractor, then tell the sells rep it's a good tractor, coording to you everything within specs and trade the sucker in and grin!

 

[RobK]

Thanks for that feedback on your machine Phil...
That helps to confirm my "gut" feeling that my "help" overstressed or tore something up inside that is causing this... To check on the brake sticking, I put it on an incline and it freewheels in neutral.
Is there a specific test that I can recommend for the dealer to diagnose this issue?
Thanks,
Rob K


Kubota Grand L3940 HST+ w/ FEL (Ohio)
Kubota B2910 w/ FEL & MMM (PA)
Kubota ZD28 Zero Turn (Home)
Attachments
5'&6'Brushogs, 5'&6'Tillers, 6'RearBlade, 6' York Rake, 5'BoxBlade, Planters, Cultipackers, 2B Plow, Discs, 3pt.Post Hole Auger
Type of Member
Homeowner & Hobby Farming (100+ acres)

 

[RobK]

Hi DieselMonk;
Thank you for your experienced thoughts and insight.
As the engine loads and bogs down, the exhaust remains clear without any missing; engine still starts easily and runs as normal until HST pedal is engaged fwd/rev under load. Trans is definately whiney compared to before that summer of abuse, but not over-the-top alarming. I'm a Christian and firm believer that what goes 'round comes around... I wouldn't pass this off unknowingly on another person or dealer... as I'm a small business person too!

I just want to "fix" it and move on... whether a fix involves a repair bill or trading her in, I don't want to be further troubled by this issue.
Thanks so much,
Rob

Kubota Grand L3940 HST+ w/ FEL(Ohio)
Kubota B2910 w/ FEL & MMM (PA)
Kubota ZD28 Zero Turn (Home)
Attachments: 5'&6' Brushogs, 5'&6' Tillers, 6' RearBlade, 6' York Rake,
5' BoxBlade, Planters, Cultipackers, 2B Plow, Discs, 3pt. Post Hole Auger
Type of Member
Homeowner & Hobby Farming (100+ acres)

 

[DieselMonk]

If you like this tractor so much, I'd check then the fuel flow out of the tank. Maybe there is dirt in it and in the lines. You should get a rapid fuel flow. It also could be sucking air somehow, or creating a vacuum in the tank (vent in the fuel cap plugged) If that didn't help nothing I'd be sitting right next to the mechanic when he checks for power output with his PTO dyno. Again, as long as the HST moves good uphill in all the ranges and has good pulling power and doesn't whine exessive, I don't think it is the problem. Did you check on the HST if the fan is still there? If it isn't there the tractor would work for a little while until the oil got hot and then lose pulling power.

Another cheap shot would be Diesel Fuel Conditioner like Power Service and run that to see if it restores power. Mix it strong, double the rating than recommendet for the first tank, then what ever it recommends after the first tank.

 

[Rocksprings]

Check your messages.

 

[RobK]

Thank you Rock Springs... Asked them and will wait to see...
Thanks so much for the tip. Sincerely, Rob