Kubota Loader Detent Kit - Help!

[srr5008]

I was having some problems with my Kubota L2900 (LA480 Loader) where it wouldn't stop going up and then it didn't want to go down at all. Also, the float didn't work. I took apart the bottom of the control valve to take a look at the ball detent assembly. I found that the small spring (which pushes the detent balls outwards for the float position) was kinked pretty good, so I figured it would be a good time to order a ball detent kit and rebuild it (items "A" on the diagram below)



I took everything apart, which was easy enough. Putting things together seemed to go smoothly as well, until I tried to operate the loader. For some reason, the joystick is extremely stiff. For example, when I lift the bucket not only is there resistance in the joystick, but the bucket keeps right on going up - it's almost like the large return spring that came with the detent kit isn't stiff enough to return the joystick to a neutral position. When I lower the bucket (and I really have to force the joystick) the same thing happens, the bucket keeps on going down on its own (note that this is not float - the float position still doesn't appear to be working). I noticed when I took the assembly apart for the first time, that the uppermost o-ring had been sucked inside the valve assembly and was wrapped around the spool further up that it was supposed to be. I fixed this, and still had the same issues with the joystick. I did notice that when I take the bottom of the control valve off (exposing the bottom of the spool and the detents) that I lose most of the resistance in the joystick. I still don't think it's returning to neutral like it should (again maybe due to a weak spring?).

Any idea guys? I've had this darn thing apart over a dozen times and I am drawing blanks. If helpful, there are some good pictures of the same spool assembly I have at the bottom of the following thread: http://www.tractorbynet.com/forums/kubota-owning-operating/143142-la680-spool-valve-leak-spewing.html

My next step will be to put the old guts back into operation (but keep the new smaller spring for the detents) to see if that fixes the issue. But I won't have time to look at it until this weekend so I wanted to see if anyone had any ideas in the meantime.

Thanks,

Steve

 

[/pine]

...I noticed when I took the assembly apart for the first time, that the uppermost o-ring had been sucked inside the valve assembly and was wrapped around the spool further up that it was supposed to be....

This speaks volumes...was the nut/bolt on the bottom of the spool tight the very first time you took the cap off the bottom?

 

[srr5008]

Yes everything was extemely tight.

 

[Leejohn]

Where are you putting big ball? Above or below the 3 small ones?

 

[srr5008]

Where are you putting big ball? Above or below the 3 small ones?

Based on what i saw online and following the order that parts were in when i disassembled, the top to bottom order is as follows: spool, 4 small detent balls, spring (which seems to pass betwen/behind the detent balls) then the large ball, then the cap

 

[Leejohn]

Well my guess was spool, spring, large ball, 4 small balls, then the sleeve. After that would come the cover, disk, then the snap ring. I have not had mine apart, but it would seem to me the small balls need pressure on them all the time until it is put in float.

 

[srr5008]

Thinking that over, that makes sense to me. I couldn't for the life of me figure out how the float was supposed to be engaged with the configuration I witnessed. I thought maybe the previous over had messed something up (I've found several "interesting" repairs) but the exploded diagram (which is very unclear) appeared to back up the original configuration. I'll have to give that sequence a try.

 

[srr5008]

Well my guess was spool, spring, large ball, 4 small balls, then the sleeve. After that would come the cover, disk, then the snap ring. I have not had mine apart, but it would seem to me the small balls need pressure on them all the time until it is put in float.

Upon further thought, and contrary to my comment above, I don't think that could work. The large ball has to be under the 4 small detent balls, or the detents would fall out the bottom. When the joystick is in a neutral position, the smaller detents get pushed inwards (towards the inside of the spool) and the small detent spring keeps them from falling out of place. When the joystick is pushed forward, the spool/dentents are pushed downwards, the small detent spring compresses, which brings the large ball into contact with the bottom of the detents, pushing them outwards to catch the lip in the cap and engage the float position.

For some reason I have resistance on the joystick and I can't get it to click into the float position.

 

[Leejohn]

I'll check tomorrow and see what way the spool is moved when going into float. Can the sleeve that goes over the balls be put on either way. (end for end)?

 

[srr5008]

I'll check tomorrow and see what way the spool is moved when going into float. Can the sleeve that goes over the balls be put on either way. (end for end)?

The sleeve is theaded on one end only, so it only goes on one way.

 

[srr5008]

So I tried a couple different spring/detent configuration. I first tried leejohn's method, putting the spring and then the big ball above the detents. There was too much pressure on the detents and no way to hold everything in place while slipping the cap over the assembly. I then tried putting the spring on the bottom and the big ball right below the detents. This didnt work either.

I did notice the stiffness goes out of the joystick when i remove the detent assembly, so my problem is definitely in the spring/detent/ball configuration.

 

[Leejohn]

Getting the sleeve over the small balls when the big ball is pushing out is going be tricky, but after getting it over then you put the end cap on. Is that the way you tried? The big ball has to push on the small ones and with total movement of the spool there would have to be something holding the ball and spring in place. The small balls roll as they move back and forth in the sleeve and they can't if the spring is between them. Also the sleeve and end cap can't go on at the same time. When you took it apart the balls should of went flying unless you were ready to catch them.

 

[srr5008]

Getting the sleeve over the small balls when the big ball is pushing out is going be tricky, but after getting it over then you put the end cap on. Is that the way you tried? The big ball has to push on the small ones and with total movement of the spool there would have to be something holding the ball and spring in place. The small balls roll as they move back and forth in the sleeve and they can't if the spring is between them. Also the sleeve and end cap can't go on at the same time. When you took it apart the balls should of went flying unless you were ready to catch them.

When I took it apart the first time, the large ball and spring were sitting in the bottom of the cap, and the small detents were in their proper place. My assumption, based on what I saw and Kubota's shoddy diagrams were that the spring being centered in the sleeve, behind the detents, was holding the detents from falling inwards. What I didn't understand was how the spring was going to stay centered on the large ball. What I saw when I took it apart looked like this:



If I understand you correctly, you think it should look like this:



I tried to install it with the large ball above the detents, but the spring was so compressed that I had trouble keeping the detents in place - they wanted to shoot all over the place. I think the only way to make that configuration work would be to hold the large ball in place with something long and thin (like a drift pin), install the cap (without the bottom piece) over the sleeve and drift pin, then try to slip the bottom plate into place and install the spring clip. Does that sound right?

 

[Leejohn]

Yes that is what I thinking it should go. That also is the way I was thinking to put it together.

 

[srr5008]

I'll give 'er a try this weekend and let you know how it goes. Thanks for the input!

 

[srr5008]

Yes that is what I thinking it should go. That also is the way I was thinking to put it together.

Well a minor victory and setback. Got everything installed correctly (large ball above the detent) and no stiffness in the joystick and it clicks into float! However when i pull back on the joystick (lifting the bucket) the joystick still isnt returning to neutral and the bucket keeps lifting. I dont have this problem lowering the bucket. Also the tractor womt stay in float. It clicks in but the minute i let go of the joystick it jumps out of float. The joystick literally springs back to the neutral position from the forward (lowering) position.

Any ideas? My next attempt (barring any ideas from you folks) will be to reuse the old internals and see if that helps.

 

[Leejohn]

Does it seem to ok with the tractor not running? If so, then I would 1st guess the spool and float are not screwed together tight.

 

[srr5008]

Does the same thing whether the tractor is running or not.

 

[srr5008]

Ok slowly but surely I am getting there. I had an o-ring in a spot where i didn't need one (tried using one that was leftover in the rebid kit in the wrong place). Little egg on my face, but with that removed the joystick now acts like it should - free moving and jumps back to neutral. However I still cant figure out the detents for float. It definitely clicks into float, but won't stay there - it pops right back into neutral when i let go of the joystick.

Any ideas? I thought about backing the sleeve out of the spool a little bit to see if the extra length pushing downwards would help, but it feels like the detent balls are grabbing pretty good, so I don't think that would help? And the sleeve was screwed in tight to the spool before (although the prior configuration was wrong, so maybe the previous owner messed stuff up and overtightened it?)

 

[Leejohn]

The small balls have to line up with grove in the sleeve. Can you just pull the cap off and maybe see where they are in the sleeve when pushed into float? Then you also might be able to screw the sleeve in or out like you thought about doing. That should tell you something.

Before you do that make sure the spool is moving the same in and out. Try pushing the spool in by hand without being hooked to the joystick