Recently acquired Kubota T1400 with HST won't drive forward or reverse

[Clacur]

Hello All, I recently acquired a Kubota T1400 with HST and when I got it, it did go in forward and reverse but was getting less and less responsive so I turned it off and removed the mower deck and when I started it back up the belt started smoking and was doing some jerking movements and now it won't drive forward or reverse. I've replaced the drive belt. Filled the HST reservoir. Raised up the rear tires and gone through the air purging process described on other threads. Suctioned out all the old HST fluid and put new fluid in. My main fear is that even without the "neutral" lever activated the wheels are able to turn in unison forward and backward acting as if the "neutral" lever is pushed in. I wonder if something is broken inside the HST? I can't find a HST rebuild kit and can only find a new HST for $2,499 (who's paying that price for a 30+ year old mower transmission???). Any suggestions other than waiting to find another mower I can buy for parts and take the HST from? None are for sale in my area currently.

 

[Bee-Positive]

Welcome aboard Clacur!!! Quite the old girl you got there. Never owned a T1400H but here's what I'd be looking at first.

So you have a belt-driven hydrostatic transmission and have replaced the drive belt (not the mower belt). Awesome.

SWAG 1 - Inspect the drive pully and shaft. Just wondering if a key has rounded over (assuming that's how the pully is connected and being 30+ years old) causing the jerking until it finally failed and no longer moved at all. The shaft may be spinning and the pully not so much.

Question - When jacked up and in neutral do the wheels spin slowly or are they acting as if your hauling right along? If spinning slowly can you stop the wheels from turning with just your hand (don't hurt yourself trying) or not? When not jacked up and in neutral does the tractor want to go forward and backwards?

SWAG 2 - If spinning slowly 30 year old seals, gaskets, may leak just enough with the neutral engaged that the wheels will turn while jacked up or the neutral solenoid is not fully engaging/disengaging if that's how your HST works.

I didn't see a WSM on Kubotabooks.com but maybe someone on OTT has one or can point you to where to find one, and you could "rebuild" the trans yourself. New gaskets and seals can work wonders and hopefully that's all it is. If not you may be looking at a new(er) mower.

 

[Clacur]

Thanks Bee-Positive!

SWAG 1: I have inspected the drive pully's as well as the tensioner and found them all to be fine.

Question answer: Wheels spin freely by me pushing on them even when the "neutral plunger" isn't engaged. I'm not getting any movement from the wheels from pushing on the forward/reverse pedal. So it won't move at all from power from the HST. Zero response from the forward/reverse pedal.

SWAG 2: No spin from forward/reverse pedal unfortunately.
Thanks for the tip to look on kubotabooks.com, I double checked and also can't find a WSM.

Thank you for your responses. You are a very helpful person!

 

[Russell King]

Since you get “no spin” from the pedal movement, have you verified that the pedal and any linkages are actually moving properly and moving what they are supposed to move?

 

[Clacur]

Yes, I've verified everything is connected properly up to the HST. However I just re-emptied the HST fluid and pulled the HST oil filter and see flecks of metal on and around where the oil filter resides... so I assume something is broken internally in the HST???

 

[North Idaho Wolfman]

That's a sign that the pistons and plates are eating each other.