Kubota RTV 900 transmission problem - hardley moves in gear!

Thanks for links. Exploded diagrams are very useful too. I have taken the rear "suction filter off" and found some debris in it (guaze or similar), not much. Looking inside it it looks quite dirty. No idea when it was last changed. Oil looks clean enough following draining. I am wondering if filter is chocked and starving pump of hyd fluid/oil? Tempted to reasemble so full filter and oil change and see if it works?? What are peoples thoughts - worth a go? If it doesn't work I trust i can collect new oil and reuse again therefore nothing to loose but a couple of hours labour? One thing i am keen to learn is that is there an alignment setting for the shaft exposed? Looking through i can see a series/sequence of holes....does this need to bet set before refitting casing? Many thanks, Dave


i have been in similar situations and put back together. "usually a mistake" i also notice the oil in the picture of the tub with you holding something above it. is that the oil that came out of the HST??? looks real bad to me. i would just rebuild it while i had it torn down but i would not proceed until i had some sort of workshop manual. yes the plates have a right and wrong way to be installed as they are what regulates the volume of oil entering the high pressure pump.

also you should get a filter cutter and take the filters apart and look for debris in the media. don't use a hacksaw get a proper cutter. anyone who has a hydrostat should have a filter cutter and inspect at every oil change,it can save you allot of trouble
 
Thanks, I will order full set of filters and oils, rebuild and retry. The oil from drain down is very dark however appears debris free. The suction filter (rear, under guard) appears clogged so will try getting a cutter to inspect further. The oil in the filter located on the right hand side, near the suction filter appears alot more gold coloured and transparent...wondering if this suggests block is present. Will take a few days to get parts together so will try and feedback. Exploded diagrams are very useful and i can now see the additional plates locations. Are these all accessible from the rear of the machine as existing stripped area or do axles etc need to be stripped? Thank you.
 
When you replace the oil and filters, make sure you use Kubota's products (OEM filters and UDT or SUDT fluid). The RTV does not like aftermarket products and many have found using non-OEM products greatly reduces performance.
 
just placed here as a note. i was taught by Caterpillar that the media in filters had a service life and not to exceed two years per filter because you run a significant chance in the media failing and being distributed throughout the system. NOT GOOD. so kinda like tires on low mileage cars and trucks you need to change them even if the service hours on the oil is low. it also is a good time to look for singes of failure in the system so the fix isn't catastrophic.
 
Thanks, I will order full set of filters and oils, rebuild and retry. The oil from drain down is very dark however appears debris free. The suction filter (rear, under guard) appears clogged so will try getting a cutter to inspect further. The oil in the filter located on the right hand side, near the suction filter appears alot more gold coloured and transparent...wondering if this suggests block is present. Will take a few days to get parts together so will try and feedback. Exploded diagrams are very useful and i can now see the additional plates locations. Are these all accessible from the rear of the machine as existing stripped area or do axles etc need to be stripped? Thank you.

I have a shop manual for the X900 on a PDF file. while your machine is a few years older with many changes before the X900, the PDF file might help you. If you want a copy send me a private message with your email address. the file is 53 MB
 
great keep us posted.i am not sure if you have to pull the axles but i don't think you do because they are part of the gear driven system not the hydro. best check with some who have done it.

here is a link to a filter cutter for reference only. i got mine from Caterpillar many years ago.

https://www.autozone.com/shop-and-garage-tools/oil-filter-cutter
I've never cut filters to inspect. Have had to drive a screwdriver through car filters to remove them.
I would have thought a hacksaw would suffice for cutting to inspect. I checked out your link to see what a filter saw looked like and the price. Holy molely ... 79 bucks for a filter saw shocked me. :eek: Why so expensive?
 
Hey Doc
the link was just so people could see the type that works best,they work kind of like a tubing cutter with two little sharp wheels that cut open the can just below the lip.better than a hack saw because it leaves no metal filings. the type shown can be had for under 30 bucks just have to shop around.
 
Thanks folks, I was close to putting a screw driver through the filter in order to get it off!! No idea when it was fitted, but it was bound well! Is there a way to flush the system whilst open? Wouldnt want to use old oil or expensive new oil to do it....is there an alternative - just incase there are any fragments floating around in there - although I guess the new filters should pick them up anyway? I guess flushing it would be a messy process anyway!! Filter cutters similar principle to alcathene pipe cutters, but a bit pricier - was wondering if a tin opener would do the trick!!! Will keep you posted on progress and outcome. Thank you.
 
Thanks folks, I was close to putting a screw driver through the filter in order to get it off!! No idea when it was fitted, but it was bound well! Is there a way to flush the system whilst open? Wouldnt want to use old oil or expensive new oil to do it....is there an alternative - just incase there are any fragments floating around in there - although I guess the new filters should pick them up anyway? I guess flushing it would be a messy process anyway!! Filter cutters similar principle to alcathene pipe cutters, but a bit pricier - was wondering if a tin opener would do the trick!!! Will keep you posted on progress and outcome. Thank you.

tried to send the file, seems to be to big for a hotmail account :-(
 
Flush with the cheaper new hyd oil. It will still cost but not like sudt2. I used something called Gold bond or Gold brand when our tractor got water in the transmission. bordercollie
 
Thanks all. I put new genuine filters and Kobota oil in, and took the opportuntiy to service the engine too. Started it up, pushed the pedal and nothing happended...I did this a few times and tried all the gears and eventually started moving - quicker than before....just!! I raised the bed and checked the drive oil level again - the oil had dropped below the lowest mark - so i topped it up again (suspect filters air locked then filled hence drop in level??). Started it up again and off it went. I tried all the gears and appears to work fine. I am used to cushman trucksters and JD Gators which generally have instant accelaration - ive noticed power is incremental on this?? I need to give it a good run to make sure I am getting a good speed range - over 100m I was only getting 15mph or so. I was a little concerned as the online manual claimed I only needed 10 litres of UDT transmission oil, however I used nearer 15 litres....however I may have been looking at a manual for a newer model?? I was constantly checking for leaks!!! Regarding the L M H ranges, can you change whilst moving or do you select before driving off? Thought I would ask before trying incase I ended up going through the windscreen!! Ive noticed the 4wd selector is limp, however it has been disconnected (not sure why..not borken, just disconnected and bolts put back in???). I will put back in place and test. Will keep you posted on further tests!! Thanks
 
Congratulations hopefully you got it all fixed up! Definitely stop to shift gears. As far as acceleration these things are turds, Typically mine wont hit TopSpeed unless it’s well packed ground or asphalt.
 
Thanks all. I put new genuine filters and Kobota oil in, and took the opportuntiy to service the engine too. Started it up, pushed the pedal and nothing happended...I did this a few times and tried all the gears and eventually started moving - quicker than before....just!! I raised the bed and checked the drive oil level again - the oil had dropped below the lowest mark - so i topped it up again (suspect filters air locked then filled hence drop in level??). Started it up again and off it went. I tried all the gears and appears to work fine. I am used to cushman trucksters and JD Gators which generally have instant accelaration - ive noticed power is incremental on this?? I need to give it a good run to make sure I am getting a good speed range - over 100m I was only getting 15mph or so. I was a little concerned as the online manual claimed I only needed 10 litres of UDT transmission oil, however I used nearer 15 litres....however I may have been looking at a manual for a newer model?? I was constantly checking for leaks!!! Regarding the L M H ranges, can you change whilst moving or do you select before driving off? Thought I would ask before trying incase I ended up going through the windscreen!! Ive noticed the 4wd selector is limp, however it has been disconnected (not sure why..not borken, just disconnected and bolts put back in???). I will put back in place and test. Will keep you posted on further tests!! Thanks


did you put in new plates? or did you just reassemble and put in clean oil?
 
I could not see or feel any defects in the plates and they were not showing much in the way of wear so decided to reassemble (although was prepared to have to open up and change again!). Need to get it out for a good run as there could be other underlying issues I guess if previous owner has been running for a while under strain. I suspect the filter were choked restricting oil flow.
 
I could not see or feel any defects in the plates and they were not showing much in the way of wear so decided to reassemble (although was prepared to have to open up and change again!). Need to get it out for a good run as there could be other underlying issues I guess if previous owner has been running for a while under strain. I suspect the filter were choked restricting oil flow.

Thanks that is good to know
 
I will post an update on transmission once i get it out for a good run on various terrains. Tonight i have been looking into the 4wd and wondering why it has been disconnected. I have now noticed the nearside front drive shaft is exposed and stripped the splines. i suspect this is why they disengaged it...so in 2wd it is the rear wheels which drive? Is this a big and expensive job to repair? Should i list on separate thread? Many thanks, Dave
 
when you say near side driveshaft do you mean the shaft that runs from the front diff to the wheel ? or the front driveshaft that runs from the transfer case to the front diff?
 
Those splines on the early model RTVs would wear down from what would become a poorer and poorer fit as the cast iron yoke of the driveshaft wore more and more. As time progressed,the steel shaft coming out of the front drive and/or the rear shaft will show more and more wear as the rattle grew louder and fit become "looser ". In shorter words, The cast iron yoke of the ujoints shaft is softer so over time the steel splined shafts wear down as the loose ness acts upon the shafts . That's how I see it becoming worn down.
bordercollie
 
Bordercollie, that is a good description - photo attached. Is this a large task to replace/repair?
 

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