TG1860G Transmission not operating smoothly

[TheBiggestofChungi]

Hey everyone. My dad has a 2006 Kubota TG1860G that he really likes, but he's having a problem with the transmission. He says that when he's got the HST go pedal wide open, it has no issues and runs smoothly. The problem is that when he goes to accelerate or slow down, the HST doesn't operate smoothly and it causes the tractor to jerk real bad. He took it to the shop a couple of years ago asking them to change the HST fluid, but they told him that "The manufacturer recommends not changing the fluid because it's a sealed unit." Which personally I think is code for "We don't want to because it's too hard." or "We'd rather just sell you a replacement HST when it fails." Does anyone have any ideas on what the issue might be?

Also, does anyone have a PDF copy of the workshop manual for this tractor? I tried searching online, but he's not going to pay $100+ for a service manual.

 

[North Idaho Wolfman]

That's one of the models you'll have to pay to get the manual, anyone that says they have it for cheap or a PDF is a scam.

You can get it here:
http://www.colemanequip.com/parts/KubotaParts/97897-12123/

Or walk into a dealer armed with a clean USB key, and they might give you a copy for much cheaper.

And on most of these smaller HST units you don't change or add fluid.
There is no provisions for doing it.

 

[lugbolt]

could be a few things

One, there is a damper on the pedal linkage that slows the rate at which the pedal can be moved. So, if the damper fails, you can easily mash the pedal as fast as you can and the transmission then just jerks hard, sort of like dumping the clutch on a manual shift. Similarly if you just let off of it all at once it will throw you over the steering wheel. Two, possible internal issue (low fluid, etc).

If it is an internal issue, there is VERY little information available for that transmission. For some reason Hydrogear (the manufacturer of the transmission) didn't give out a lot of information for that particular unit.

Yes it can be serviced. Again because of the lack of available information for that unit, unless you need to go into it for some reason, or it's leaking, it's not recommended to open it up. Typically if there IS an internal issue, many times it damages so many components that it then becomes a replacement situation rather than a rebuild.

And lastly, to drain/refill, you have two options. One, suck the fluid out of the vent/fill hole in the top via fluid extractor. Two, remove the transmission from the machine and then flip it upside down on the bench after plugging the vent somehow so that oil doesn't run everywhere. Then remove all of the bolts in the pan (cover) and you will likely break a few of them because that's just how they are, then remove the cover and remove the fluid. Then you get to drill out the broken bolts. Also replace the filter while you're in there but be really careful with the filter-it sits on a base. The filter base is removable and the filter is normally stuck to it, so when you go yanking on the filter the base comes out with it. Under the base is a spring & ball, there are several places it can fit but only one is correct--and that is not shown in the shop manual OR in Hydrogear's books to my knowledge. I have fought these from day one and I hate them. While the pan is off have a look down inside the case. You see any metal flakes? Replace the transmission. The way many HST's are made, if you see metal in them, the damage is usually pretty extensive and since hydrogear doesn't sell many parts for them, and the ones you can get are not cheap, it becomes more of a "which costs less" situation and usually the replacement option is less expensive.

 

[ve9aa]

I don't know what to tell you about the "jerking transmission" ( I am not a mechanic)

:. I've been running a TG1860 (diesel) for 16-ish years and ~500+ hrs (it now has 980+ hrs on it) and have had a very slow leak ever since day one. I believe the leak is the HST. The thing is super expensive to fix or replace entirely, so I put up with the very slow leak/seepage.

Only when I notice the top speed slowing down quite a bit or the transmission "slipping" (not the correct term) do I top it up as there is not a good way to check the level.

So, every 4-5 years or so I top it up a tad via the vent tube, so it's possible. The thing then pulls like a freight train.