L5450 Drivetrain Freeplay

[simmonslr]

I have started noticing that my drivetrain seems to 'coast' and then 'catch-up' when going over a small rise at slow speed. Seems most noticeable when in the lowest gear at mid-to-high throttle. Started a year or so ago but seems to be getting more pronounced now.

Do I need to start worrying about a pending repair? Any guesses where to start looking? Only 700 hours on the tractor.

Thanks.

 

[sandyc]

My bx2380 has done that from the get go.

 

[rbargeron]

Hi again Larry - I looked up our last contact (1917) - about the L5412 backhoe & subframe you found.

I've been puzzling over the 'coast and catch up' you're noticing. The L5450's drive is all gears, no lost motion anywhere I can think of - except maybe check the rear wheel lugs for tightness. The machine has a lot of mass and might seem to lurch back and forth if lugs are loose. The wheel centers are double-thickness at the bolts - very stiff so may not groan or make noise if loose. I can't quite picture anything serious wrong inside the machine. Take care, Dick B

 

[simmonslr]

My bx2380 has done that from the get go.

Thanks for your response. I wondered if it might be 'the nature of the beast' sort of thing.

 

[simmonslr]

Hi again Larry - I looked up our last contact (1917) - about the L5412 backhoe & subframe you found.

I've been puzzling over the 'coast and catch up' you're noticing. The L5450's drive is all gears, no lost motion anywhere I can think of - except maybe check the rear wheel lugs for tightness. The machine has a lot of mass and might seem to lurch back and forth if lugs are loose. The wheel centers are double-thickness at the bolts - very stiff so may not groan or make noise if loose. I can't quite picture anything serious wrong inside the machine. Take care, Dick B

Hi Dick

Thanks for your input, I will check the lugs this morning.

The backhoe has gotten a lot of use. Thanks for all your help. I should update that post. I had a problem with a relief valve dumping a 1/4 cup of fluid under heavy load, but when I re-plumbed the tractor based on your input (and the original Kubota diagrams), the problem stopped. Made me kind of lose faith in the local dealer, who did the original plumbing placing the hoe 'in line' with the loader.

The only lasting issue I have is an inability to get the main horizontal pin to take grease.

 

[jeff9366]

Do you have HST tractor transmission?

HST transmissions are pump and fluid driven. HST transmissions are not mechanically connected to the engine or wheels, pumped hydraulic fluid is the intermediary. There is lag/lead associated with almost all pumps.

Many good videos on YouTube illustrating HST operation.

 

[simmonslr]

Do you have HST tractor transmission?

HST transmissions are pump and fluid driven. HST transmissions are not mechanically connected to the engine or wheels, pumped hydraulic fluid is the intermediary. There is lag/lead associated with almost all pumps.

Many good videos on YouTube illustrating HST operation.

This is a manual transmission with the wet, hydraulically actuated, Everclutch, which seems pretty bullet proof, looking at the posts here.

Thanks for the suggestion.

 

[rbargeron]

Jeff, - the pump/motor hydraulic circuit in hydrostatic drives is maintained locked full with no air in it (no lost motion). A small charge pump keeps the circuit filled with around 450 psi on the low side, replenishing clearance leakage at the valve plate and actuator. Working pressure on the high side can reach 5400 psi. The connection to the drive wheels is a positive-displacement "hard" coupling, with near-zero slip. My L48 has an HST - but my L5450 is all gears except for hydraulic actuators on the F-R clutch packs, which once engaged, have no backlash. Take care, Dick B