Transmission Trouble

RobandKubota

New member

Equipment
RTV 900
Nov 24, 2020
5
0
1
Ponder, TX
Good Morning,

I have a Kubota RTV 900 that has a sluggish transmission. I believe it’s a 2008. It recently had a brand new Kubota diesel installed but I have no idea if the transmission sluggishness presented itself before or after the new engine. Any idea on where to look or what could be wrong?
Any help would be greatly appreciated!
 

RobandKubota

New member

Equipment
RTV 900
Nov 24, 2020
5
0
1
Ponder, TX
When was the last time transmission fluid was changed? Is it full?
I don’t know when it was changed as I just purchased it but the fluid is full and very clean. The engine was replaced by a Kubota dealer right before I bought it so I am not sure if they changed it or had to change it when they replaced the engine.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,764
2,948
113
North of Pittsburgh PA
Good Morning,

I have a Kubota RTV 900 that has a sluggish transmission. I believe it’s a 2008. It recently had a brand new Kubota diesel installed but I have no idea if the transmission sluggishness presented itself before or after the new engine. Any idea on where to look or what could be wrong?
Any help would be greatly appreciated!
Perhaps it would help to get some more answers if you explained more what a sluggish transmission's symptoms are...
 

RobandKubota

New member

Equipment
RTV 900
Nov 24, 2020
5
0
1
Ponder, TX
Perhaps it would help to get some more answers if you explained more what a sluggish transmission's symptoms are...
Basically what happens when you put it in gear and depress the gas pedal is you feel the vehicle move forward but very slowly. As you continue to depress the gas pedal, the rpms continue to increase but forward momentum does not match the rpms whatsoever. It does increase in speed but lags the rpms of the engine. Kind of like it’s pulling a load. It is the same way in reverse.
 

PoTreeBoy

Well-known member
Lifetime Member

Equipment
L35 Ford 3930
Mar 24, 2020
2,792
1,515
113
WestTn/NoMs
Basically what happens when you put it in gear and depress the gas pedal is you feel the vehicle move forward but very slowly. As you continue to depress the gas pedal, the rpms continue to increase but forward momentum does not match the rpms whatsoever. It does increase in speed but lags the rpms of the engine. Kind of like it’s pulling a load. It is the same way in reverse.
EDIT: we actually have an RTV-900, not X900.
I have a little experience operating an RTV-X900. You should be able to see if there really is any resistance (brakes dragging?) by putting the range lever in neutral, parking brake off, 2WD on a hard, flat surface and see if it rolls freely. Assuming it does, what you're experiencing could be due to some adjustments or could just be the 'nature of the beast'. As you know, this machine has a hydrostatic transmission like many SCUT's instead of a variable ratio belt drive like many U/RTV's. But instead of a separate throttle and transmission controls like on tractors, the 900 has both controlled by the accelerator. I think there must be some adjustment in that linkage that would affect the RPM to speed response. The 900 our refuge bought new several months ago seems to have a little more lag now between the engine revving and starting to move than it did when new. I don't know if it could be due to the engine breaking in or the linkage wearing/stretching a little or ?. It'll never be as smooth taking off as our previous RTV-400CI with the CVT, but it's a much more rugged workhorse.
 
Last edited:

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,195
1,883
113
Mid, South, USA
x900 is a different (totally) transmission

the description sounds normal for the old 900's they were slugs

about the only thing you can do is test the charge relief pressure, and then the high pressure relief in both forward and reverse. If pressures are ok, nothing else to do. Maybe pull the filter and see if there's any metal shavings in it. If there is, what color are they? Brass? Steel? Aluminum?

There was a very few of the early 900's that had some hst port block wear plate issues. I wouldn't even have mentioned it but I do remember doing a couple. Not all that hard.
 

PoTreeBoy

Well-known member
Lifetime Member

Equipment
L35 Ford 3930
Mar 24, 2020
2,792
1,515
113
WestTn/NoMs
x900 is a different (totally) transmission
Thanks for pitching in. Do you know when the model changed? Does the 900 have hi-low-neutral-reverse, 4WD and throttle/speed interconnect like the X900?
EDIT: turns out we actually have a -900, not X900.
 
Last edited:

RobandKubota

New member

Equipment
RTV 900
Nov 24, 2020
5
0
1
Ponder, TX
x900 is a different (totally) transmission

the description sounds normal for the old 900's they were slugs

about the only thing you can do is test the charge relief pressure, and then the high pressure relief in both forward and reverse. If pressures are ok, nothing else to do. Maybe pull the filter and see if there's any metal shavings in it. If there is, what color are they? Brass? Steel? Aluminum?

There was a very few of the early 900's that had some hst port block wear plate issues. I wouldn't even have mentioned it but I do remember doing a couple. Not all that hard.
This helps...is there any kind of shop guide available for me to reference when testing the pressures and identifying in depth troubleshooting?
 

PoTreeBoy

Well-known member
Lifetime Member

Equipment
L35 Ford 3930
Mar 24, 2020
2,792
1,515
113
WestTn/NoMs
This helps...is there any kind of shop guide available for me to reference when testing the pressures and identifying in depth troubleshooting?
There's an RTV-900 WSM and OP Man at kubotabooks.com. It shows the -900 to have a 3 range gearbox and ours only has 2, so I'm wondering if we have a -X900 after all.
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,910
1,374
113
Kansas City, KS
There's an RTV-900 WSM and OP Man at kubotabooks.com. It shows the -900 to have a 3 range gearbox and ours only has 2, so I'm wondering if we have a -X900 after all.
RTV900 has the Park Brake to the Left side of the seat, RTV-X900 has the Park Brake to the Left of the steering wheel, sticking out of the dash.