HST slow to neutral

[ZackaryMac]

Mosy of the time when doing a lot of forward/reverse work, I find the HST not returning to center or neutral on it's own. It doesn't feel like a consistant decrease in speed, as the damper would do if gooped up, but more similar to a worn spot somewhere in the system. The pedal comes pretty close to middle, but the speed is about 20% somethimes. It makes for interesting work when you release your pedal to stop and it keeps on moving. Of course this usually happens when I'm near something I can break or fall in to. /forums/images/graemlins/crazy.gif
Funny thing is, when the engine is stopped and I try the pedal, it moves freely and returns to center quickly. No notchiness at all.

Has anyone else ever experienced this? And if so, what was the cause?
Thanks. /forums/images/graemlins/grin.gif

 

[Junkman]

Try cleaning the pedal pivot with some brake cleaner spray and then re-lube. I was having problems with my hydro pedal on my BX and this resolved the problem. I believe that the lube attracts the dirt and then it starts to get sticky. Cleaning and re lubing worked for me, and it was about a 5 minute fix. Occasionally, the pedal sticks, but that is a quirk of the BX series. Some work better than others and there is no rhyme or reason as to who is going to have problems and who isn't.

 

[gsxr1100]

I have the same problem with my BX22. I did the cleaning, spraying, lubing etc. To date, nothing has worked. So the BX is going to the dealer to fix the slow moving pedal and the Fuel Sending unit leaking.

I know how it feels to stop and it keeps moving...Wonderful feeling. Nice when working by the garage and almost go through it!

 

[ZackaryMac]

</font><font color="blue" class="small">( I know how it feels to stop and it keeps moving...Wonderful feeling. Nice when working by the garage and almost go through it! )</font>

Exactly! And for some unknown reason, when this happens, my foot is just above the HST pedal, and twice now I've stomped on it in panic mode, brain thinking BRAKE, foot, having no brains, follows orders without question. More acceleration just seems counter-productive at this time.

The HST pedal has a grease fitting in the end of the pivot shaft, so lube isn't a problem. I keep everything well lubed. I'm thinking that if this tractor was used a lot for mowing as I was told, it was kept near a constant speed, and wore a small detent somewhere that I can't readily see. I know I have to find and fix, though. Sooner or later it's gonna cost me, one way or another. /forums/images/graemlins/frown.gif

Thanks for the responses, guys. /forums/images/graemlins/wink.gif

 

[grandad]

The HST pedal connects though a linkage arrangement of rods and levers, obviously, to the tranny. There is a neutral adjustment somewhere in that linkage so it can be set to return to the neutral position. A Kubota dealer should be able to tell you how the adjustment works on your particular model.

If there is rust or other crud in the area of the linkage, it could be binding or maybe it's just worn. Hopefully your problem is something external like that, which would be simpler (and cheaper!) to fix than something in the tranny itself.

 

[ZackaryMac]

Well, I took the cover off tonight and discovered the pedal is connected to a cam on the side of the transmission, and on the bottom of this cam is an inverted "v" where a lever with a spring at one end, a small wheel in the center, and a bushing at the other ride against this cam. The pivoting end of this sping-loaded arm has an adjustable eccentric. After taking it apart, I find the bushing is kind of tight, so I gently clean and ream it to free it up a bit. Synthetic lube, re-assembly, and adjustment of the eccentric later, it feels better. Out I go again to push dirt with the 3ph blade. Works great, until I have a load against the tractor, and it will sit there and spin the wheels against the load until I tap the HST pedal. The pedal itself is absolutely NOT sticking. My next plan of attack is to put a slightly stiffer spring on the return lever, as I feel it may be worn inside the tranny and so needs more "return" pressure to overcome this.
It came to the point tonight that either I fix it or ruin the tractor, or worse. It's rarely a problem with mowing, however it's not right or safe. I'll find a solution somehow! /forums/images/graemlins/tongue.gif

 

[v8dave]

I looked at a used B21 and it had this same problem. The seller said it was a minor adjustment. Because the B21 also had a few other problem, I decided to not buy it.

Later, at a rental yard that rents lots of Kubota products, I talked to the yard owner and he said the HST creep was a problem with all his Kubotas. And, that it could be adjusted out. But, it didn't stay adjusted for very long.

Now in that busy rental yard, not very long probably means every several hundred hours. (He turned his tractors at 2,000 hours which they rolled up in 2 to 3 years.) He had 10 to 15 Kubotas, so, he was probably adjusting several a month. I would suspect, that a homeowner user wouldn't have to do this but every several years. He kind of indicated they ran well for the first year, then required periodic adjustments.

Even so, I still bought a new HST Kubota.

Bottom line--once you fix it it should last a while [with moderate personal use]. Unless you are a contractor, in which case, it says you should think about getting a new tractor.

Of course I didn't ask what the adjustment was. /forums/images/graemlins/frown.gif I didn't have a tractor at that point. /forums/images/graemlins/smirk.gif

 

[ZackaryMac]

I put a heavier spring on the return arm, and it looks like this cured it. It will stop so fast now when I take my foot off the HST pedal, it'll drag the back tires. That's fine. At least when I say Woow, it Woows. /forums/images/graemlins/grin.gif
The pedal is harder to press now, perhaps a bit too hard for maximum speed, so a slightly softer spring may be in order, but at least I'm in the right, and safer, direction.
Result: Pucker factor greatly reduced! /forums/images/graemlins/tongue.gif

 

[Charley]

Just picked up my BX22 today from the dealer. It was in for the similiar "stuck pedal" syndrom. My repeated attempts at spot lubricating didn't seem to help. The dealer dissassembled the entire linkage, cleaned, lubricated and reassembled. One noted item was some factory paint that appeared to be binding one of the link points (I don't know exactly which one). It works great now. We'll see if it stays that way.

 

[Steve_S]

Great stuff guys. After 350 hrs on my BX, I'm pretty used to the HST "stick" but would love to get it taken care of. I like the spring idea, as I've tried just about everything else over the course of 3 years or so. The pedal stuck after the first week I had it and instead of running it to dealer I decided it was a tractor and I'd deal with it.