Kubota RTV 900 transmission problem - hardley moves in gear!

i need to ask a very important question>>>have you properly adjusted the peddle travel in relationship to the HST speed lever and injection pump throttle lever? reason i ask is if you don't have proper adjustment there it could be causing the problems you are experiencing.
 
Thanks again to both for your help. My filters are as follows: Rear, white W2ITSHK710 ans side, orange - W2ITSHK700. So all appears ok based on colour coding (I could not relate codes on Messicks, although it is a very useful website).
New plates all put in with assembly lube, all spotlessley cleaned and put back together with great care and attention but same results (L 5mph, M 7mph H 10mph). I tried pulling the mechanism on the top of the hst box and managed to get it to 15mph...but very puzzled as to why this happened as all linkages appear to be allowing full stroke. In desperation i had to take a full load of rubble up a farm track (1.5miles uphill). It managed no problem although very noisy with high revs! Will try not using it again until fixed properly. Oil levels remain ok with no major leaks detected.i thought i had a leak but think it was all the oil and old oil on to of tranny box when heated up went fluid again!! Need to get power washer out!! Think i will revert to dealer and update them on my work to plates etc. Will keep you all posted on finding. I did try knocking piston but it didn't make any difference unfortunately (wasn't sure how hard i should hit either!!). Thanks again.
 
if i understand your last post it says you removed the servo and pushed on the piston andit didn't move. then you reinstalled and got 15 mph out of it. is this correct?
 
I had the machine jacked up and achieved these speeds using foot throttle. While jacked up and engine running i manually pulled the lever directly on top of the hst block which got machine to 15mph. Does this make sense? Thanks again.
 
did you have the HST lever disconnected from the cable? also when you hauled off the trash did the traynn feel like it had power but not speed?
 
Nothing was disconnected, that's what i can't understand as throttle is linked so should do same and seems to be at full stroke. The mechanism i pulled is in photo at end of screwdriver. Seemed alot more powerful when pulled but speedo only reached 15mph. I trust the pump the screwdriver is sitting on is for tipper only? There is a small oil leak from hose serving that (pivoting joint - wet/dark looking hose in photo). Thanks
 

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if the system is out of adjustment it is possible to get full rpm without getting full travel of the HST lever. or visa versa
 
Hopefully that is the problem. Should i send to dealer to adjust or is there an easy guide available to follow? Definately getting full revs and this excercise suggested there is scope for more speed/travel. Thanks
 
Dvaepat4 said:
Hopefully that is the problem. Should i send to dealer to adjust or is there an easy guide available to follow? Definately getting full revs and this excercise suggested there is scope for more speed/travel. Thanks
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no you shouldn't need the dealer. i think there is a description of the adjustment early in this very thread. basically you need to disconnect the small cable that operates the throttle lever on the fuel pump and the end that controls the HST lever on the servo. then make sure the foot peddle has full travel and adjust the stop if necessary so you can get the peddle all the way to the end of travel just before it begins to bind on itself. then have someone hold the peddle to the stop and reconnect the throttle cable to where the lever is just contacting the max rpm stop. then with the peddle still at the bottom reconnect the HST lever and adjust the end of the cable if you need to so the HST speed lever is almost at it's max travel in the fastest direction. then release the peddle and start the machine with the rear wheels off of the ground and with the engine at idle see if the rear wheels creep. if they do you will need to adjust the neutral valve or back off of the speed lever a tiny bit.
 
I've disconnected throttle cable and maxed out travel and also travel on HST but still have same results. I also disconnected throttle and did throttle and hst manually, prioritising throttle before hst and vise versa bit it made no difference. Starting to think it may be a faulty relief valve (one built into hst block)? Or perhaps still sticky piston?
 
Appears so, can't stop or slow down manually when jacked up and have driven it up hill with a full load with little impact on drive (did slow down a bit on steeper sections and had to change to M at one stage). Will try disengage hst link tomorrow fully and operate it manually to ensure full stroke (didn't fully disengage hst end earlier so will try again). Thanks
 
take it out and get it real warm. work it with a load on hills or pull something heavy. constantly changing the speed abruptly. the heat and pressure might pop the piston loose. if you have good torque at the wheels i would bet that the servo is sticky. the positive displacement pumps would cause low torque it they were leaky. if the servo piston isn't moving then the swash plates aren't getting a full swing.
 
should be easy to disassemble and clean. first record the location of the adjusting screw so you can put it back to where it was. i would either get a set of gauges or take to dealer for adjustment when you get it done.
 
Thanks very much. I will investigate compatibility and postage. If fitted i suspect i will still need dealer to calibrate it? Screw on current servo is sticking quite far out but it's covered in dirt suggesting it hasn't been moved in a long time. Maybe it has been screwed out to avoid workers thrashing it? I went on a half hour trip last weekend with a load and thought the downhill run would maybe help free things off but it didn't. Will try again this weekend - trust i need to stop between gear changes?! It was very hilly and as said took hills quite well.
 

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there is plenty of information on the servo on the net. you should google "kubota rtv servo adjustment" and also search in this forum same same. before you move any of the screws.
 
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