rtv 900 jumping from forward to reverse by itself

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seedsower

New member
Hi all.First post on here and really hoping someone can help!
I have a 06 rtv 900 with4800 hours
We put new parts in the hst pump a while ago which improved speed greatly but now 100 hours later it has lost a little of this speed but still nippy enough.
Big problem now is that every so often when you come to a stop in one direction it abrubtly starts going the opposite direction without the gear lever moving.
If you apply the brake it stops but moves in the wrong direction again when the brake is released.
If you acccelerate a little it stops and wont move again until you want it too,this time in the right direction.
I have asked some mechanics and they have not heard of this problem.
Any input very welcome
 
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you need to adjust the speed control lever for creep. if the lever is moved past center the machine will reverse it's direction. somewhere in the past someone made a rocker peddle so they could change direction like the tractors do. i think for plowing snow.
 
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The speed control lever is the one on top of the transmission at the rear i presume?its adjusted by a turnbuckle link?
i was at this with one wheel jacked up .If i went a long way in one direction the wheels would reverse so i presume i had the right thing.
I failed to make any improvement but maybe there is a procedure to follow or something that i dont know about.
I had it not creeping but still sometimes it acted wrong
 
sounds like you were adjusting the correct lever. that lever controls the servo that controls the swash plate. it is possible that you need to fine tune the center position of your servo piston. as always i ask when was the last fluid and filter change? in years not hours unless it has been recently changed? and then if changed was oem fluid and filters used?
 
kubota oil and filters used a few months ago.I took off a plate with six studs holding it on beside the lever which sounds like it was the servo piston housing.I could not see anything obviously wrong.
Is there a knack to adjusting the centre position?
The problem im having seems to be a rare one,which makes me wonder if its not something deeper than adjusting neutral
 
usually the servo doesn't require adjustment unless this problem has persisted since the machine was new or someone has tampered with it. in order to adjust you will need to make sure all of your linkages are to spec first. then when that is done you can jack up the rear both tires in the air and proceed to adjust the center servo neutral position. most want just a little rear creep at idle to help alleviate hard shifting. do you have a WSM?
 
Dont have a wsm.So you are saying both wheels off ground and the wheels turning a tiny bit backwards in neutral?
When i tried adjusting before i seemed to have to make a big change in lenght to the adjuster to make any differences.Cant see obviious play in any linkages though
 
proper adjustment would be no creep with both wheels off the ground engine idling in forward high range gear. there should be no movement in gear neutral. speed peddle neutral is that point were the swash plate is held in a neutral non tilted position. many adjusted just a little rear creep so that the gearshift would pull into neutral easy after a stop. the linkage measurements are important not so much the wear.
 
Thanks so much @aurthuritis for your help!
I spent a while adjusting and the forward reverse problem seems to be improved, it only happened once since so maybe a little more in the same direction will workIt seems abit of a vague art,i adjusted so it barely stopped creeping but then had reduced speed so went the other way a couple of threads and it seems fine now.
I now seem to have better speed in medium than before though high is about the same as before,if that makes any sense
 
Setting this in the workshop doesnt seem to work for me.I have to adjust a little then work it for a while to see the results.
Im almost there anyway i think.Is there a reason why readjusting this is necessary or how often has it to be done generally?
My issue is stopping the jumping in direction without losing power, a fine balance it seems
 
it shouldn't need readjusted. or adjusted at all. if you don't have a wsm you should get one because there are many things that all work together in balance. i suspect either someone has tried to tweek it or something inside isn't working.
 
i have adjusted it a good few times and it seems very hard to get the balance right.too much in one direction seems to stop the reversing but loses a lot of driving power.ive had the machine a few months and put 200 hours up before this started.
Could there be an internal problem of a different kind?
 
adjusting the creep shouldn't affect speed or power. all the servo does is use hydraulic power to activate the swash plate. if it is centered then the swash should be in flat or neutral position and the wheels won't move. if you are losing power i would suspect an internal leak. could be a bypass valve. there is a flow chart in the WSM that shows the flow and direction of the high pres oil. are you loosing engine rpm when you adjust the speed lever?
 
i dont think i am losing engine rpm,more that the machine wont move until you rev higher and at top rev there is less speed.Thats when you go in one direction adjusting to completetly stop the reversing problem.
I am puzzled as to how this adjustment affects forward reverse as this control only moves one direction irrespective of whether you are in forward or reverse gear
 
i had a look at the manual thats linked in one of the threads here but it basically says go to dealer for adjustment.
As for oil flow diagrams ive seen one before and it was a maze to me
 
in order adjust this properly you need to establish a good working knowledge of the system and it's operation. you need a WSM
 
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