TG1860 (diesel) HST transmission oil change Maintenance

[trainbuff57x]

Hey all
I have a Mower with !000 hrs. on it and the hst is starting to not respond (weak on uphills, the machine is in great shape ,so I'd like to keep it, looking to service the HST tranny but having trouble finding info on it, I do know it has an internal filter but cannot find out the procedure for changing oil and filter, It doesn't have a drain plug or a fill cap. it does have a vent and 2 plates on the bottom , Just wondering if anyone has ever done anything with these HST trans, also the correct fluid, (Onwer's Manuel states 20w-40w engine oil) not sure if that is correct, The local Kubota guy hasn't worked on any of them, I am going to try to put some pictures, if anyone has any info or point me in the right direction that would be Greatly Appreciated
pictures ar of the top and bottom of the HST, also of the Machine Any help would be great!!
Thanks,
Mike M.

 

[GreensvilleJay]

FWIW, worked on other 'no drain plug' HSTs and simply removed from tractor, pull vent off, turn upside down and let drain for 24-48 hours(splitting the case really helps !!). I replaced oil with FULL SYNTHETIC as the MFR recommended. FS is much better handling the high temperatures the HST gets.
If it's 'weak going uphills' parts are wearing out( pistons 100 + 090 parts). If caught early, oil will help.
The 'problem' is HST gets hot(from use and clogged fins), oil gets hot and some oil vapour gets vented. Next time same thing but MORE oil gets vented and HST is hotter cause, well ,there's less oil. Over time hotter and more venting means not enough oil and pistons wear out.....

 

[trainbuff57x]

FWIW, worked on other 'no drain plug' HSTs and simply removed from tractor, pull vent off, turn upside down and let drain for 24-48 hours(splitting the case really helps !!). I replaced oil with FULL SYNTHETIC as the MFR recommended. FS is much better handling the high temperatures the HST gets.
If it's 'weak going uphills' parts are wearing out( pistons 100 + 090 parts). If caught early, oil will help.
The 'problem' is HST gets hot(from use and clogged fins), oil gets hot and some oil vapour gets vented. Next time same thing but MORE oil gets vented and HST is hotter cause, well ,there's less oil. Over time hotter and more venting means not enough oil and pistons wear out.....

Yes that's what I figure ,, thanks for the reply, just wondering if anyone out there has any Experiance with this model and some specific thoughts with this perticular model I'l hold off for a few days to see if I get anyone else to chime in Thanks
Mike M.

 

[TheOldHokie]

Yes that's what I figure ,, thanks for the reply, just wondering if anyone out there has any Experiance with this model and some specific thoughts with this perticular model I'l hold off for a few days to see if I get anyone else to chime in Thanks
Mike M.

Kubota used Hydro-gear integrated transaxles in some of their garden tractors. Look yours over for a data plate. Documentation for Hydro-gear transaxles can be downloaded from the Hydro-gear website.

Dan

 

[D2Cat]

Might do a search for member "lugbolt". He has worked on many of them and has given a lot of helpful feedback.

 

[trainbuff57x]

Hey All
Thanks for the response's
After a few days of the best research I could do ,and from your response's , since the HST is still working (but weak on uphills) I am going to go with the ,"remove the drive turn it upside down,Bleed it dry for 1-3 days then refill , with full syn. 20W-50W. method, that GReenvillejay suggested, I might even try to open up the pan and try to clean the filter, if the bolts will cooperate , We'll see, it will be out this morning and go from there , hopefully that will have a good impact, if not I will go from there, look into rebuild, the machine is in great shape and worth saving if the cost is not too prohibitive ,
If anyone has more info or other tips, It will all be Greatly appreciated
Thanks,
Mike M.

 

[TheOldHokie]

Hey All
Thanks for the response's
After a few days of the best research I could do ,and from your response's , since the HST is still working (but weak on uphills) I am going to go with the ,"remove the drive turn it upside down,Bleed it dry for 1-3 days then refill , with full syn. 20W-50W. method, that GReenvillejay suggested, I might even try to open up the pan and try to clean the filter, if the bolts will cooperate , We'll see, it will be out this morning and go from there , hopefully that will have a good impact, if not I will go from there, look into rebuild, the machine is in great shape and worth saving if the cost is not too prohibitive ,
If anyone has more info or other tips, It will all be Greatly appreciated
Thanks,
Mike M.

If ths oil change does not fix things it may make more sense to buy a new or used transaxle.

Dan

 

[whitetiger]

I am going to go with the ,"remove the drive turn it upside down,Bleed it dry for 1-3 days then refill

You could have just drained it like the rest of us by removing the 2 bolts from the charge pump and removing it. All fluid drains out.

 

[trainbuff57x]

 

[trainbuff57x]

 

[trainbuff57x]

Update
Have the tranny out and drained, Oil was Black ,no visible metal and did NOT smell Burnt, (So that was a Plus) ,all the bolts holding the plate on are loose, going to open it up and check and clean the internal filter , Hopefully the plate comes off and nothing gets displaced ,
Should be back together Monday and I'll give an update on the results , if not good I'll be looking for input on a rebuild or options,
Thanks for the input so far,
Mike M.

 

[TheOldHokie]

View attachment 173052
Update
Have the tranny out and drained, Oil was Black ,no visible metal and did NOT smell Burnt, (So that was a Plus) ,all the bolts holding the plate on are loose, going to open it up and check and clean the internal filter , Hopefully the plate comes off and nothing gets displaced ,
Should be back together Monday and I'll give an update on the results , if not good I'll be looking for input on a rebuild or options,
Thanks for the input so far,
Mike M.

I didn't have to look very hard to find this.

https://www.lawnmowerpros.com/pdfs/hydro-gear/k12111111a.pdf

Dan

 

[trainbuff57x]

Just an update ,
Opened it up , removed filter and fork with the magnet , cleaned and replaced both, sealed it and filled it with 20w-50w SYN. engine oil (what it called for). reinstalled the transaxle,
It ran much better and the Whinning is not very apparent , In my opinion its a lot better than before,
(BUT NOT LIKE NEW FOR SURE) I will use it this season , If it starts to fail it will need to be addressed,
I could not find a replacement, But talked to a Hyro/gear Guy and he told me the parts that are most likely the issue that is making it weak , His bet is the center block (not sure if that is the exact name)
he said that it is Alumnum and the pump and motor are steel or that is what usually wears out ,
so if anyone has a line on a replacement (NEW) let me know I saw them online for $7-$8 hundred, (which is doable) or the parts that are probably needed would be $500, so I'll see how it goes , more research and use it like it is for now,
Thanks for the response and Help
All appreciated,
Thanks,
Mike M.

 

[TheOldHokie]

View attachment 173199 View attachment 173200
Just an update ,
Opened it up , removed filter and fork with the magnet , cleaned and replaced both, sealed it and filled it with 20w-50w SYN. engine oil (what it called for). reinstalled the transaxle,
It ran much better and the Whinning is not very apparent , In my opinion its a lot better than before,
(BUT NOT LIKE NEW FOR SURE) I will use it this season , If it starts to fail it will need to be addressed,
I could not find a replacement, But talked to a Hyro/gear Guy and he told me the parts that are most likely the issue that is making it weak , His bet is the center block (not sure if that is the exact name)
he said that it is Alumnum and the pump and motor are steel or that is what usually wears out ,
so if anyone has a line on a replacement (NEW) let me know I saw them online for $7-$8 hundred, (which is doable) or the parts that are probably needed would be $500, so I'll see how it goes , more research and use it like it is for now,
Thanks for the response and Help
All appreciated,
Thanks,
Mike M.

That model seems to be NLA. I found some references to K1211-1121 as a replacement

Hydro-Gear K121111121 - TRANSAXLE | P & P Small Engines

TRANSAXLE

pandpsmallengines.com

 

[trainbuff57x]

Yes T.O.H.
I saw that yesterday and called a few of them this morning , and they all said it wasn't available anymore ,Go figure why it is still on the site,
Thanks