i don't think you will have any problem exchanging the diff assembly. it should be pretty simple once you have the HST out. just look for and make a note if there are any shims between the housings or the diff mount. when you re install the new HST assembly back into the tractor you will need to confirm the gear lash between the ring gear and pinion. i don't think you will have any problems. does the WSM describe this process?
Kubota RTV 900 transmission problem - hardley moves in gear!
- Thread starter PACKASAURAS
- Start date
haven't heard from you for a few days??? i'll bet you are out in that fixed up RTV riding the trails. I Hope
Sorry for the delay, i didn't get notification of your post and was just coming on to provide an update! Been reviewing matters and decided i was prepared to replace hst therefore had nothing to loose (only my time) to have a go at replacing the damaged swash plate and see what happens. If it works i will have saved over £1000 if not it will cost me an additional £90!! I opened up side and managed to get circlip on drive off. The bearing on the inside must be pressed. I did not have access to pullers so tried various things to try get shaft out from the rear end of the machine but i failed. I then, very carefully, managed to work and force the swash plate out over the splines, out through the rear (this meant i didn't have to open up side!!). New swash arrives tomorrow so will see if i can get it back in that way (possibly not if dowel is set in swash). Some photos attached for reference. Was wondering if i could start up machine and test speed increase without axle and wheels or will that give false readings without associated weight/resistance? Just thought it would give me instant results and if it fails save me from stripping down again for new hst!! You can see how much wear in on swashplate/guide seat....nit sure how this has happened - vibration? However confident this is where effective power transfer from lever/piston was failing....will see what happens!!
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yes that shaft is a machine fit but you should be able to pull it out without to much effort if you need to. great Job look forward to see the results.
you could put a split type bearing puller behind the splines and clamp it on lightly then pull on that. you could probably adapt a slide hammer to pull it out. does the end of the shaft have internal threads?
Parts arrived....however metal "dowel pin" appears bonded so will not manage to get back in the way i got it out. Also wondering if the last person working on this machine has pulled pin out and went in this way resulting in loose pin working/eroding swash? Looking to pull shaft out this evening...update to follow!
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That should improve things a bit. i wonder what caused that failure? could the high pressure relief be adjusted to high??? i have heard of that beeing done to improve performance. after you get it running you might want to get the pressures checked.
I do wonder if someone previously has replaced this swash plate and thought it was a good idea to remove the dowel, push swash plate in from rear over shaft and reinsert dowel in position via piston housing. The dowel appears resin bonded or similar but you could prob force it out if you wanted....im not trying!! Ok good news...YES you can remove circlip from side and withdraw shaft out of rear. This allows you to drop old swash plate and insert new....I felt like I was on a role tonight!! but have ground to a hault. One of the new piston seals arrived broken....so tools down and waiting on new one... Tried swash and piston in place and all moving nicely. I used a bearing splitter and dent puller to withdraw shaft and worked very well. Photos attached, more to follow when seal arrives!!
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i don't think someone removed the dowell. i do suspect that someone has set the high side pressure relief to high. that would require a terrible amount back pressure on that dowell to hold the pumps in phase. after a while the dowell failed because it is the weakest link. the wear on the bearing shells also testify to the theory.
Yes and Yes. or get yourself some gauges and do it yourself,you can tweak the pressure some but not much. you probably ought to get a laser tachometer so you can check RPM also.
in order to check pressures you have to have hot oil and check stalled at a specific RPM.
in order to check pressures you have to have hot oil and check stalled at a specific RPM.
did you get it going??????
On the last leg hopefully....trying to get rear axle back on as i type!! Any tips?!!!. Once on i am ready to test! Top tip for anyone doing deepest swash place replacement....put circlip back on before closing up rear hst....i learned the hard way and had to openen up as pressure on bearing was too much to get it back in....!!
Ok, axle back on....what a pain doing it as a one man job!!! Bit late in evening so didn't get to test it fully (neighbours near by!!). Jacked up started, run for one minute then switched off...checked hst oil and needed topped up. Run again put into gears and there is some adjustment needed ( creeping in reverse direction even in forward gears). When accelerated it shot up past 20mph...wife came into garage and told me to stop making so much noise...so test abandoned and will continue tomorrow. At this moment looking good though 
GOOD NEWS.
i'll bet you are out ridin with the wind in your hair and bugs in your teeth. aren't you??
Haha, ok....still jacked up.. Low - 7mph, Medium - 15mph, High - 25mph and reverse - 15mph. Still need to sort creap/wheels rolling but that is current situation. Next stage is getting off jacks and running around tracks...but at the moment all seems well. I notice an imbalance when on jacks (rear rising and falling ever so slightly when accelerating) but suspect this is normal and reaction of momentum of wheels turning? Looks like i have a small leak on front axle so will investigate that next...!! Will keep you posted on road test!!