G6200 HST rebuild possible?

[Gtijake]

Long story short the input shaft on the HST is no longer with us.

According to Kubota the hydrostatic pump on my G6200 isn’t repairable, as it’s sold complete as a unit and they don’t sell individual parts.

I’d much rather rebuild it and install a new input shaft than shell out $1400 for a new pump (plus bits and pieces associated with it), even just throwing in a new shaft would probably be fine if it’s even possible.

Worst case I’ll open it up and see for my self. I have a manual lathe and would at least give making my own input shaft a try depending on how complex the other end of it is. Anyway, this is my second post here, thanks for reading and hopefully I’ll find a solution here to get the ‘ol G series back in business

 

[Egressman]

Long story short the input shaft on the HST is no longer with us.

According to Kubota the hydrostatic pump on my G6200 isn’t repairable, as it’s sold complete as a unit and they don’t sell individual parts.

I’d much rather rebuild it and install a new input shaft than shell out $1400 for a new pump (plus bits and pieces associated with it), even just throwing in a new shaft would probably be fine if it’s even possible.

Worst case I’ll open it up and see for my self. I have a manual lathe and would at least give making my own input shaft a try depending on how complex the other end of it is. Anyway, this is my second post here, thanks for reading and hopefully I’ll find a solution here to get the ‘ol G series back in business

Dont say can't. you would be surprised what can be saved. If you have to make a shaft the splines will be your problem, need a mill and indexing head!

 

[Gtijake]

Im not sure if it***8217;s splined on the interior end, but the end that broke off originally had a key way. After that failed I drilled through the coupler and shaft and held it with a 1/4 20. After a few hundred hours that egged out till near failure so I attempted a weld repair oversized, then flap disked it back down to size with a new coupler...didnt last long, but it was worth a shot

Overall its still a nice machine, just under 1400 hours on it and really no other issues other than regular deck maintenance I was gonna do next.

 

[CaveCreekRay]

Jake,

Welcome aboard!

Wow... the shaft went? The first thing that popped into my pea-sized brain was: Why?

Is it a load on the hydraulic system? The pump should be protected behind a pressure relief valve. (Wolfman can check the schematic for that machine...) That shaft is way-overbuilt for the load. My first inclination is your HST drive motor is toast inside.

Do you have any idea what the service life was for this machine? Did they ever service it on schedule? Were the filters changed upon service? If not, the damage causing the load on the shaft may be internal to the pump.

Here is a link by a crazy Canuck guy who really knows his stuff. If you don't mind an occasional F-bomb, this link will give you an idea what is inside your variable displacement HST control...

Starting at about 2:30... This will reinforce to everyone with an HST why you need to service the HST fluids ON SCHEDULE!

https://www.youtube.com/watch?v=0IjrU5bUbUc

Buying a new one may be the cheaper and easier option. Having a new one machined may run you $300-400 and it may fail if the overload is internal to the pump.

Good luck and keep us informed as to what you find...

Ray

 

[eserv]

The g6200 has a Eaton model 11 transmission in it. They were very common in many makes of garden tractors back then. your best bet is a used one. Here is a link to a manual for them. http://www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pll_1617.pdf There were a few different models depending on shaft style and rotation direction.

 

[eserv]

This bolens unit has a splined input shaft but otherwise will be the same as yours. https://www.ebay.com/itm/Bolens-H18...721198?hash=item3631dbc82e:g:nVoAAOSwVjlay5W-

 

[Gtijake]

Thanks for the replies guys! I have some reading to do now.

The long story is I’ve been running this mower for about 20 years now, bought it from my dad.

Anyway probably about 10 years ago it broke the flex plate coupler between the prop shaft and the coupler that mounts to the input shaft on the pump. Probably just fatigue cracks, as those flex plates are super thin.

That happened two or three times the same summer(now in hindsight the prop shaft probably bent a little the first time it broke the flex coupler, because it happened at full power and was very violent) so we got fed up and made an aluminum spacer to delete the flex plate set up all together. It ran like that issue free for five years.

Fast forward to five years ago shortly after I bought it from my dad, the key way broke that holds the input shaft to the coupler/flange and obviously spun making the tractor inoperable. I called the dealership and they said it was $1400 for a new pump, having just dropped $1000 buying the mower and just bought my first house that wasn’t sounding so great, so I drilled both the shaft and coupler and stuck a 1/4 20 in...problem was it was right before I had to fly out for work and my yard needed cut, so I used what I had which was a bolt at least 1/2” too long. So the grip length prevented it from ever being tight on the coupler, just bottomed out the lock nut. Surprisingly it didn’t vibrate, the tractor ran great, and I forgot all about it (or just didn’t feel like taking it all apart to swap in a correct length bolt.

So now, two days ago I took it apart because it was starting to vibrate. That bolt not being tight had almost completely cut the input shaft off. Maybe 1/4” is all that was left of the 1” or so shaft...not good. So I broke out the MIG and built it back up. Hardfaced the whole thing, ground it down to size, modded the new coupler I bought and drilled both to do the ol 1/4 10 bolt trick again (the right length this time). It looked pretty decent and I hopped on to cut the lawn with my four year old. About five minutes in the shaft came apart...I wouldn’t be so disappointed if I hadn’t just spent he afternoon working on it lol, but hey in the name of saving $1400 on a pump I gave it a good run

 

[Gtijake]

I called one of my buddies dads today who bought a g5200 (we think, he wasn’t 100% sure either) a few years ago and doesn’t use it.

His son thought it had engine issues, but turns out it’s the deck that needs some TLC. He said he’d make me a deal on it if I could use it or the parts, because he’s lost interest. The only real problem being it’s in Ohio, and I live near Charlotte, NC.

In the mean time, we stole the PTO belts and a bracket/spring off my G6200 to fix my next door neighbors G6200 so we could both mow today. He liked mine so much we found him one last year. Turned out to be a good move for situations like this where both are broke lol

 

[Gtijake]

Still haven***8217;t come up with a good solution here, I***8217;ve had a few people say they were interested in buying my tractor as is, which is probably the route I***8217;ll take.

Leaning towards upgrading to a Z411 48***8221;