engine brake / coasting

P

poke

Member
I took the tracks offa my x900 which eliminated alot of rolling resistance. Now I notice that when I take my foot off the pedal going downhill the engine RPM will drop to idle but the vehicle will not stop, it will actually slowly accelerate (depending on how steep the hill) to a slowly rising whine.
Not what I want at all!
So, for you tranny gurus out there, what terms do I search for, where do I point the wrench? Must be an adjustment somewhere.
Thanks for your help.

CHeers
Fritz
 
Yeah, at least on my '08 it's adjustable. Have to remove the spring loaded valve, adjust, reinstall and test. Might take a couple tries.

Curious why it would have changed though. Also curious if a track system would put more stress/load on that system?

I installed an aftermarket coast valve to eliminate that function. I use the brake pedal if needed and like it much better.
 
oh Waite!!! you have an X900!!! i think there is a linkage on the side of the tranny with an external adjustment for that. the coast valve adjustment is for the non X models. sorry for the confusion! my bad
 
I don't think it really changed because of the tracks. But since the tracks are each a heavy vehicle in their own right with considerable rolling resistance... my expectations had changed. I vaguely remember the unit picking up speed on zero pedal, going down a steep slope. It will catch control if you give it some pedal but I don't want it to change logic on me when I try to go dead slow.
Thank you for your input.
 
aurthuritis said:
oh Waite!!! you have an X900!!! i think there is a linkage on the side of the tranny with an external adjustment for that. the coast valve adjustment is for the non X models. sorry for the confusion! my bad
Click to expand...

If you are talking about what I think you are talking about,,,, that adjustment came in '07 I believe. What it does is trigger the HVT release when the brake pedal is depressed.

I adjusted mine so it releases the HVT just a pinch after the brakes are actived. This actually disabled the quick stop function somewhat. But mostly it improved the binding in gear problem.

Then the internal valve can also be adjusted to change it even more. I bought an aftermarket valve which works great for my uses.
 
Richard

The tranny on my RTVX 1100 is completely different than the one on my 1100. the X model doesn't have the same pressure relief system. on my 08 1100 i replaced the stock valve with a coast valve and am now very happy with the shifting and it doesn't stop suddenly.so i hope the rear u joints will last longer.
 
aurthuritis said:
Richard

The tranny on my RTVX 1100 is completely different than the one on my 1100. the X model doesn't have the same pressure relief system. on my 08 1100 i replaced the stock valve with a coast valve and am now very happy with the shifting and it doesn't stop suddenly.so i hope the rear u joints will last longer.
Click to expand...

That's my deal too!!!!! I think that's a LOT of stress on driveline.

Do you notice any other differences in driveability of the two machines??
 
I agree that sudden deceleration is hard if the rear u-joints have to take it all.
However I have trained myself to ease off gently and I am almost always in 4wd so that would distribute /cut the stress in half.
 
Yeah, I think operator evolvement can overcome a lot of the stresses of the system.

I also think, with minor modification by Kubota, it could have been designed selective. A simple lever or knob on the dash to choose modes.
 
I still got this problem:

...when I take my foot off the pedal going downhill the engine RPM will drop to idle but the vehicle will slowly accelerate (depending on how steep the hill) to a slowly rising tranny whine.
Not what I want at all! Not with a heavy trailer behind me...
The engine somehow is disengaged and does not do much / any braking.
So, for you tranny gurus out there, what terms do I search for, where do I point the wrench? Must be an adjustment somewhere.

I have a x900 workshop manual but a search for "coast" turns up nothing.
"idle" gets a zillion hits but none relevant that I can fathom.
"brake" shows in the HST section :dynamic brake pressure check port... aha!
Then there is a High Pressure Relief Valve (Dynamic Brake) deep in the guts of the HST...
Hmmmm so one would give it half a turn and test?

gulp.
 
I am not sure on the X 900 but i think there is an adjustable nut on the drivers side rear that can be turned one click at a time to get the relief you desire.
 
Nothing on the left side but on the right side there is a largish nut out of which protrudes a deep cap of some sort. As I understand the diagrams it is inline with the HighPressureReliefValve ... I'll stare at it some more. Thanks
 
Did you install the track system? Wondering if any adjustments or modifications are performed during installation?
 
I am not sure. but on the other side there should be a threaded rod that comes down at an angle toward the rear of the machine and it has a nut with a vee machined on it and a spring seat for it to ride on the end of a lever. i think you can adjust that to get the desired effect. but make sure you count the clicks just in case you need to return it to it's original position.
 
I installed and removed it myself. The only adjustment was the steering limiter up front.
Back there, I DID adjust the unload valve linkage so the brake pedal would actually do some unloading.
 
if memory serves me there is a black shock looking thing that is adjustable.It has to do with the dynamic braking.Mine went bad 2 months in and it was like having no dynamic braking at all.I replaced it and all is fine for 10 years now.Ill loook it up tomorrow when im not jalf asleer.Look in the OM for dynamic braking.
 
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