110TLB bucking violently - any thoughts?

[sweetjeep]

Hi Folks,

I have a 2005ish 110tlb and it's bucking violently when driving. I have searching the internets for relevant information but can't find what I suspect I need.

The problem is as such: When driving (hydro trans) in any range, the tractor is bucking violently. At any throttle input or any foot "throttle" input. FWD and Reverse. Basically it acts as if you were rapidly stomping on and then releasing the direction input (pretend that the foot inputs respond instantly). I can hear the valves open and close as the tractor is bucking so it strongly leads me to think it's an electrical issue.

However - if I use the creeper it will drive just fine. Sllloooowwwwly, but no bucking and rodeo action. So this leads me to think there is an issue with the foot pedal controls. Though I don't know if the creeper lever talks to the same inputs at the trans controller as do the foot pedals.

I searched a little to see if anyone has any write ups on diagnosing such an issue, but no such luck. I had this issue poke it's ugly little head at me once upon a time before but it went away as fast as it appeared so there was nothing to diagnose.

There are no trouble codes and the motor is running fine and all the rest of the hydraulics are running fine. Fluid level is exactly correct.

Any thoughts from the brain trust out there? Or am I regulated to the joys of my local Deere Service Department?

Thanks all!

 

[kennyd]

Since it does it in both FWD and RVS I would not suspect the pedal controls since they are two separate ones (potentiometers). I am not familiar enough with the eHydro controllers to help more, sorry.

 

[sweetjeep]

That was a little bit of help, and appreciated!

 

[TedLaRue]

From your description, it sounds like the drive train is causing this "bucking" (not the engine).

Does the hydrostatic drive use the same hydraulic fluid as the rest of the hydraulics? Did you consider that you might have a strainer or filter plugged up causing it to starve for fluid at normal speeds, but not at creep speed?

If one hydraulic fluid runs everything, then as an example, if a seal is breaking down in one of the hydraulic cylinders, the bits of rubber can plug a strainer pretty quickly.

 

[sweetjeep]

Ted: It's absolutely not the motor. It's far to violent. We're talking **** near pulling wheelies here.

As far as I know all the hydro fluid is shared. I pondered something along your strainer theory, but when I went to the lowest gear and just barely touched the foot pedals, I still got the bucking. Though at those speeds and pressures (<- ?) it's only subtle pauses in motion. You can hear the whine from the gears being driven stop for a split second and then come right back. Basically the same audio pattern as the physical pattern when trying to go faster.

 

[TedLaRue]

It certainly sounds like the transmission is cavitating (sucking air instead of fluid).

I tried to pull up the parts diagram for your hydrostatic transmission, but they don't show it broken down.

My thinking:
There is a breakdown in the transmission of power between the engine and the wheels, and it happens suddenly and recovers suddenly.

Where, between the engine and wheels is there not a metal-to-metal connection? The hydrostatic transmission.

How could the transmission suddenly lose and regain power? Lack of fluid. How could that happen?
Not enough fluid (but you said the fluid level is ok).
Lack of delivery of the fluid?
Clogged filter? (you said you could feel it even at very slow speeds)
Is the pump belt driven? A greasy spot on the belt might cause the pump to briefly stop working each time that spot passed the pump's pulley.

Still thinking...

 

[TedLaRue]

More thoughts:

I'm not familiar with your machine. What is the difference between the "ranges" and "creeper". Is creeper different from just being the lowest range?

Do you select ranges using a clutch, or can you just shift like an automatic transmission in a car?

If there is no clutch, then you have a combination of a hydrostatic transmission and an automatic transmission. If that is the case, then your transmission will have "band clutches" in it which brake one gear or another in a planetary gear arrangement to get various speeds. Maybe one of the bands is slipping? Maybe one that is required for the upper ranges but not the creeper? Bands can be adjusted, but that's not something your average shade tree mechanic does. I hope that's not your problem....$$$!

 

[scrappy isb67]

From your description, it sounds like the drive train is causing this "bucking" (not the engine).

Does the hydrostatic drive use the same hydraulic fluid as the rest of the hydraulics? Did you consider that you might have a strainer or filter plugged up causing it to starve for fluid at normal speeds, but not at creep speed?

If one hydraulic fluid runs everything, then as an example, if a seal is breaking down in one of the hydraulic cylinders, the bits of rubber can plug a strainer pretty quickly.

nope, a screen clogged would shut EVERYTHING down, it wouldn't come and go like the OP is experiencing

More thoughts:

I'm not familiar with your machine. What is the difference between the "ranges" and "creeper". Is creeper different from just being the lowest range?

Do you select ranges using a clutch, or can you just shift like an automatic transmission in a car?

If there is no clutch, then you have a combination of a hydrostatic transmission and an automatic transmission. If that is the case, then your transmission will have "band clutches" in it which brake one gear or another in a planetary gear arrangement to get various speeds. Maybe one of the bands is slipping? Maybe one that is required for the upper ranges but not the creeper? Bands can be adjusted, but that's not something your average shade tree mechanic does. I hope that's not your problem....$$$!

the range shift is just a collarshift type transmission that goes AFTER the hydro, there is no "clutch " and is nothing remotely like an "automatic" transmission. The hydro is an E-hydro(electronically controlled)

OP it sounds to me that the control system is screwing up. in creeper mode, are the foot pedals used? it does definitely sound like the potentiometers on the pedals are messing up

 

[jenkinsph]

I can't think of the correct terminology at the moment but there are some sensors connected to the computer and drivetrain that might be causing this problem. Hopefully someone with a clear head can chime in, feel I am having a senior moment and the terminology is escaping me right now. It does sound like the tranny is "hunting" and is loosing a sync signal from a sensor. Haven't had this problem with my 110 but will stay tuned, hope you get it figured out.

 

[sweetjeep]

Thanks guys.

Ted: As far as I understand think of my tractor like this - The diesel engine connects to a big hydraulic pump. The hydro pump then plumbs to everything else. A motor for the transmission, a pump for the loader and/or the backhoe. Though I haven't tried to run both at the same time, I don't suspect it would work well.

The tractor has 3 geared ranges from which I can choose. a,b,c. C is transit range which is a scorching 10-12 mph or so. Where A is a peaks around 2-3 mph. The creeper is a directional control (fwd/rev) which has a thumb "throttle" that essentially emulates the foot throttles. The idea is that when you are on the backhoe and need to move the tractor you can reach behind and use these controls to move the tractor with out having to flip the seat and then climb into it and vice versa. It works the same as the foot throttles but appears limited to only the same effective speeds as A range.

Jenkinsph: I agree with your thinking, only I can't find any resources to tell me what those magic sensors are, or how to further diagnose. My hope is that this is an uncommon issue and once fixed, isn't likely to be a problem again. I hope...