Is this possible, or is it me?

[dave1949]

Yeah, but I hate to dump $90 worth of new fluid. I just guess it will go a little slower, just like me.

Do you recall thinking it went faster back when you went from Kubota UDT to Ambra?

Does your Kubota manual call for UDT or SUDT?

 

[boggen]

not a clue...
--you have 4x4 / mfwd engaged and on hard solid ground. 4wd drive gives a different feel vs 2wd. 4wd can just seem like a stiffer / slower turning/moving thing.
--have air still in the system. keep checking the fluids.
--ya got funky shoes / boots on, that your not use to wearing, and not moving the pedal good.
--ya moved low/med/high gear shifter and didn't realize it.
--you have emergency brake partially put on. (been there done that *coughs*)
--funky shoes/boots on/ cover all's on that don't fit. and partially pressing on the brake pedals.
--the floor mat or like was slighty pressing on the pedal from last time dealer did there thing. and now ya fixed the culprit (moved floor mat back off the pedal) been there done that by mistake. took me a while to figure that one out on the blazer.
--not much info on your tractor what i did find, it all stated a HST (hydrostatic transmission), these transmissions should have some sort of internal pressure relief valve inside of them (more like combo's up with something else) and the spring or like is suddenly out of adjustment, letting oil by-pass, vs being used for powering the machine.
--something hyd or like is putting a load on the engine. ((leveler / joystick partially being pushed or like))

======
HST and like hydro transmission. they have high torque at low RPM's (turning the wheels on tractor), if ya push peddle all the way down... you have little torque but higher RPM's (wheels turn faster), but if you put a load on the tractor. and in to high of a gear (low, medium, high), your ground speed will begin to suffer badly as internal pressure reliefs kick in. going to a lower gear (low, medium, high), you may actually gain more ground speed, due to the internal pressure reliefs not kicking in. and full hyd fluid going to turning the wheels vs just part of it. this can more be seen if tractor has a "road gear" say 24ish max MPH's (+/- a couple MPH, for each tractor out there). road gear just doesn't have the torque. it is all speed. toss a wagon or trailer behind it, that is heavily loaded, and bye bye road gear. ((not enough tractor for what you are wanting to do))

=======
you might have 3 radiators / oil coolers on tractor. (1 radiator up in front for keeping engine cool), generally 1 oil cooler directly behind the radiator up in front for hyd oil for the (FEL, 3pt hitch / rear remotes), and then possibly 1 more oil cooler (transmission oil cooler), located mid way some place on tractor. say behind engine towards the ground. if you have one, double check it is not all clogged up...
Messick's | Dealer for New Holland, Case IH, Kubota, Cub Cadet and More | Online Parts, Sales & Service. easy way to look up parts for most tractors out there. might be able to look up a part number if transmission oil cooler exists on your tractor or not.

========
the ugly thing, maybe something is broken or got lodged up some place. from simply draining out the old fluid. ((happened before ya drained fluid, but for what ever reason the sloshing / draining of fluid let that culprit find its way into some place and causing you problems)).

========
some tractors have 3 to 4 fill spots / drain spots... for hyd fluid.
fill locations... not always below. but gotta start some were.
--power steering pump (located generally up in front by fan belt)
--FEL / rear remotes (up in front most of the time some were above the engine normally)
--transmission (underfloor mat, or off to a side of transmission)
--rear end / final drive (little bit further back than above transmission check / fill location, maybe on rear end of tractor).

did ya drain more locations than you thought and did not fill all the locations back up?

==============
been there done that with majority of above... hopefully something might ring a bell, and get things figured out.

 

[orezok]

not a clue...
--you have 4x4 / mfwd engaged and on hard solid ground. 4wd drive gives a different feel vs 2wd. 4wd can just seem like a stiffer / slower turning/moving thing.
--have air still in the system. keep checking the fluids.
--ya got funky shoes / boots on, that your not use to wearing, and not moving the pedal good.
--ya moved low/med/high gear shifter and didn't realize it.
--you have emergency brake partially put on. (been there done that *coughs*)
--funky shoes/boots on/ cover all's on that don't fit. and partially pressing on the brake pedals.
--the floor mat or like was slighty pressing on the pedal from last time dealer did there thing. and now ya fixed the culprit (moved floor mat back off the pedal) been there done that by mistake. took me a while to figure that one out on the blazer.
--not much info on your tractor what i did find, it all stated a HST (hydrostatic transmission), these transmissions should have some sort of internal pressure relief valve inside of them (more like combo's up with something else) and the spring or like is suddenly out of adjustment, letting oil by-pass, vs being used for powering the machine.
--something hyd or like is putting a load on the engine. ((leveler / joystick partially being pushed or like))

======
HST and like hydro transmission. they have high torque at low RPM's (turning the wheels on tractor), if ya push peddle all the way down... you have little torque but higher RPM's (wheels turn faster), but if you put a load on the tractor. and in to high of a gear (low, medium, high), your ground speed will begin to suffer badly as internal pressure reliefs kick in. going to a lower gear (low, medium, high), you may actually gain more ground speed, due to the internal pressure reliefs not kicking in. and full hyd fluid going to turning the wheels vs just part of it. this can more be seen if tractor has a "road gear" say 24ish max MPH's (+/- a couple MPH, for each tractor out there). road gear just doesn't have the torque. it is all speed. toss a wagon or trailer behind it, that is heavily loaded, and bye bye road gear. ((not enough tractor for what you are wanting to do))

=======
you might have 3 radiators / oil coolers on tractor. (1 radiator up in front for keeping engine cool), generally 1 oil cooler directly behind the radiator up in front for hyd oil for the (FEL, 3pt hitch / rear remotes), and then possibly 1 more oil cooler (transmission oil cooler), located mid way some place on tractor. say behind engine towards the ground. if you have one, double check it is not all clogged up...
Messick's | Dealer for New Holland, Case IH, Kubota, Cub Cadet and More | Online Parts, Sales & Service. easy way to look up parts for most tractors out there. might be able to look up a part number if transmission oil cooler exists on your tractor or not.

========
the ugly thing, maybe something is broken or got lodged up some place. from simply draining out the old fluid. ((happened before ya drained fluid, but for what ever reason the sloshing / draining of fluid let that culprit find its way into some place and causing you problems)).

========
some tractors have 3 to 4 fill spots / drain spots... for hyd fluid.
fill locations... not always below. but gotta start some were.
--power steering pump (located generally up in front by fan belt)
--FEL / rear remotes (up in front most of the time some were above the engine normally)
--transmission (underfloor mat, or off to a side of transmission)
--rear end / final drive (little bit further back than above transmission check / fill location, maybe on rear end of tractor).

did ya drain more locations than you thought and did not fill all the locations back up?

==============
been there done that with majority of above... hopefully something might ring a bell, and get things figured out.

Pretty much "None of the above"

Doing what I have done a hundred times before with same settings/boots etc. Tractor has 3 drain points, but only one fill point.

I have been running WIX filters as the closest Kubota dealer is 60 miles away. I got the K stuff because I was near a different dealer while on a camping trip. I still have one WIX filter and I might just change it out to see if the Kubota filter might have more flow restriction.

I've had the tractor since new 10 years ago so I am very familiar with it's characteristics.

I also plan to do a pressure test to see if that's up to snuff.

Incidently the 7800 has the same HST as the 2610 and 2910.

 

[orezok]

I think I might have discovered my problem. I went out this morning and pulled the tranny dipstick. Put it on a paper towel and NO oil on the stick. Put the stick back in and checked again and it's about 3/4 up between the marks. For some reason, I think I'm getting a false reading after removing the stick. I may be low on fluid.

I'm going to check it again in a couple of hours.