B2X20 MMM height adjuster.

[vinzuki]

I have had my new B2920 with mmm a little over two months now and am impressed with its quality and performance that comes with the KUBOTA name. However the height control for the mmm is very dissapointing. After mowing for 2 hours the deck would not hold adjustment after lifting it up to travel . It would always fall back to the 1" setting scalping the grass. After reading and studying the manual and looking under the tractor to see how it works it seems to be under engineered. There is a shaft that goes under the tractor thats called the lift shaft. On this lift shaft is welded a metal finger about 1/4 wide that rides on a cylindrical cast iron gear with steps spiraling up it for the various heights. Now mind you this 60" deck weight is 322# and all this weight is riding on this metal finger no bigger than your pinkie finger. Remember this deck is suspended ,the wheels don't hold any weight.multiply this when you hit some bumps. Mine was assembled properly by the dealer but there was about 3/16 play side to side in that lift shaft and the finger was only touching a small portion of the step and wore it out in no time.My dealer was very helpful and called KUBOTA and said they was aware of this problem,but have no fix as of yet. He ordered me a new shaft and stepped gear but being a mechanic I chose to modify it myself.The first thing you need to do is shim the lift shaft so it has 0 side to side play in it and the finger is centered in the step in the gear. I used a die grinder to dress up the steps in the gear making my favorite 3.25" a little deeper.I also filed a new tip on the finger with a hand file. It seams to be working fine for now ,but for how long? So any one with a new B series take a looksee under your tractor and see how yours working.

 

[rudegoose]

Yep, been there. done that. got that t-shirt.
Got my new 2920 in early May, it had the height adjustment problems you described starting on Day 1.
I've got the 54" mower deck, had the exact same issues... it was back and forth to the dealer numerous times.. at first, they said Kubota knew about the problem, but didn't have a part to fix it readily available.. so the dealer made an attempt to fix it, it sounds similar to what you did yourself... it still didn't adjust correctly though, but it would at least stay where you put it so you could mow at the same height. I appreciated that the dealer at least fixed it/sort of so I could use it while waiting for Kubota.
Finally got a call from the dealer that the new assembly had come in, so they replaced it....(I think it was early/mid-July) been working fine ever since. Don't know how the 'new part' differs from the 'old part', but it works (knock on wood).

Love my new tractor, but it was extremely frustrating to spend that kind of $$$ and get less than perfection from the start!

 

[Hoosier_Daddy]

I have the B2620.. 60MMM and have not had a problem so far. But, you have my attention.. I have not had the MMM off yet but will soon. Guess I will look around to see what is holding up this heavy mower.

Every new toy has it's bugs. Just glad Kubota fixes the problems..

 

[RRbota]

New member here. Been lurking for the past 8 months or so and finally joined. Man, what a great forum!!!

I bought my 2620 in May, after a lifetime of lawn and garden tractor experience (mostly Gravely). For the most part, I really like it. I've even found that using the diff lock will minimize the number of times I'm frustrated by the common Kubota complaint: "why can't they put the brakes on the other side, so you could actually use them??"

I noticed the "Wal-Mart qualilty" height adjustment method the first time I put the 60" mmm on my tractor, and expected problems. I immediately machined a spacer for the lift shaft, as vinzuki mentioned, and raised the deck wheels so they are a minimum of 1" off the ground. Still, whenever uneven ground is encountered (constantly on my yard) and tension is taken off the adjustment cam, it turns slightly, changing the height adjustment. Maybe this is intentional.....it's made the "brakes are on the wrong side" issue not seem so frustrating!!!! (yes, I am laughing.....the brakes really aren't THAT bad!!! Besides, I knew where they were BEFORE I made my decision to buy!!!)

What I have done the past month, is to change my approach. Instead of expecting the height adjustment cam to hold up the mmm (unrealistic, given the lack of engineering of the components), I'm using it as more of a "position control indicator". With the mmm raised, I set the desired height. Then, slowly lower the mmm, while still holding on to the adjustment knob. As soon as I feel the lifting shaft arm touch the adjustment cam, I stop lowering. Then I close the 3 pt hydraulics lowering valve, using the knob just to the right of the height adjustment knob (in front of the seat). This causes the 3 pt hydraulics to hold up the mmm instead of relying on the Wal-Mart cam, and is working much better. During the 2 hours it takes me to mow my yard, I may need to readjust the height once or twice (probably due to a slight amount of hydraulic leakdown from the weight of the mmm bouncing around), but that is much better than needing to readjust after every lap!!!

I'll have to get in touch with my dealer to see if he knows anything about the "new & improved" adjustment assembly that rudegoose mentioned.

Sorry about the long post, but hey.......it's my first time!!!

 

[Evil the Weasel]

My 2620's problem so far is that the height on the dial does not match the height of the blade from a level concrete floor. It's off by an inch. I posted some info about this in the buying/pricing forum. I mowed about 2 acres tonight and did not notice the mower height change during that, but I will check it out. I don't think they have mine adjusted right. The orange link arms make contact with the height adjustment linkage so I have to go easy when raising the deck (and not use the detent to raise it up quickly). The knob does have side to side play too. I will ask my dealer about this new part. That would be great if it is true.

 

[LBrown59]

It would always fall back to the 1" setting scalping the grass. After reading and studying the manual and looking under the tractor to see how it works it seems to be under engineered. .

What fell back the knob or the deck?
If you had the knob on 1 naturally the deck will drop to 1.

 

[vinzuki]

What fell back the knob or the deck?
If you had the knob on 1 naturally the deck will drop to 1.

I would be mowing at 3.25'',raise the deck and then lower it. You could watch the knob turn when you lowered it back down. Mine had so much play in it what was happening was the clevis in the connecting rod that goes back to the lower link,it was hitting the little nub that sticks out of the stepped cam . (that nub is used to lock the deck in the full up position). Any how I got my customer product survey in the mail today from kubota. They will get an earful on this.

 

[Evil the Weasel]

When the cam is not engaged on the height adjuster spiral gear, there is play in the knob. When I lower the deck to the set height there is no play at all and the deck does not change height during operation. I just mowed 4 acres of lawn tonight and it was fine. My only complaint is that the threaded adjusters are bottomed out (they shouldn't be according to the book), and my height is off by an inch. I can only cut at 3" max with this setup. I'm suspecting the height adjuster is the wrong one. Oh yeah one more complaint, the bracket that replaces the spacer on the left lower link is chewing into my lower link arm. I don't think it should be like that. The mechanic didn't think it was something to be concerned about. I checked the length of the connecting rod and it is spot on. I have a friend with a lot of tractor knowledge and we are going to go through the setup step by step and see if something is amiss down there.

Even though I'm off by an inch on the dial, this thing mows like a BEAST. And I can't believe how maneuverable it is. I have about 45 trees to contend with and I thought the ROPS would be smashing into everything. I have about two limbs total that need to be cut for smooth sailing. Keep me posted and I will let you know what I discover (if anything).

 

[nh_bota]

It's interesting to read the issues that people are having with their 2x20 decks... I had the same issue when I started to mow with mine about 3 months ago (i.e. it was an inch off). I made some adjustments and now have the height almost perfect. Haven't had an issue since. I'll keep my eyes open now that I know people are having problems.

 

[LBrown59]

I would be mowing at 3.25'',raise the deck and then lower it. You could watch the knob turn when you lowered it back down.

It shouldn't do that.

 

[RRbota]

My height adjustment knob is loose and wobbly when the deck is raised and not resting on the cam. The looseness is gone when the deck is resting on the cam, as would be expected. I could reluctantly learn to accept this sloppyness....although I still do not feel it belongs anywhere near a deck costing what we have to pay for these things. What irritates me more is what happens when the scalping wheels run over a high spot and move the deck up, taking the weight off the cam; As the deck is lowering back to it's set position, the cam has rotated enough (from all the sloppyness) so that it ends up at a different setting....always lower. This means that as you continue to mow, if you don't continually check your height, your grass is getting cut shorter and shorter.

Disregarding the height issue, I am very pleased with the actual cutting the mower does. Maybe I'm just expecting too much????

I don't have the problem of limited height, like Evil does. I have gone through the setup numerous times.....adjusting and readjusting anything that could be adjusted. What I have found, is that I need to LOWER my deck an inch before it reaches the "TOP" setting on the cam. That's making me wonder if I have the correct cam. If I want to really lock the deck at full height, I could always pin it up.....except that I can only get one of the pin holes to line up (that was one of the reasons for all the adjusting and readjusting). In those instances I find it's easier and quicker to simply remove the deck. The "pin-up" position is also an inch above the TOP position on the cam.

 

[LBrown59]

I would be mowing at 3.25'',raise the deck and then lower it. You could watch the knob turn when you lowered it back down. Mine had so much play in it what was happening was the clevis in the connecting rod that goes back to the lower link,it was hitting the little nub that sticks out of the stepped cam . (that nub is used to lock the deck in the full up position). Any how I got my customer product survey in the mail today from kubota. They will get an earful on this.

This seems to be limited to the B series .
I have 3 BXs and have not that problem on any of them nor have have i ever heard of it being a problem fron anybody else.

 

[jcaledon]

My B2620 is in for its 50 hour service. This thread has scared me to some degree about the deck. I have had some issues, and thought that it was just an adjustment issue, but asked the dealer to look into it anyways. They spoke with Kubota Canada and made some adjustments to the height adjuster, which they say should address any issues. But they did not know of any new replacement parts for the height adjustment. I'm getting the tractor back tomorrow, and they assure me that the deck should be fine from here on in. Has anyone had any luck with this new part - if someone has a part number or pic, it would be helpful. I don't think that my dealer is BSing me - it may be that this fix is not yet available in Canada. My dealer assures me that if the part becomes available, that they will notify me and install it.

PS. The 50 hour service cost just under $500 Cdn, plus delivery!!! I'm getting a 20% discount which will bring it down - but this is really expensive. I plan on doing future oil changes etc. myself, but wanted to have the 50 hour service done by the pros.

 

[jcaledon]

Well, I got my tractor back yesterday. The 50 hour service was done. Almost wish I hadn't mentioned the mower deck issue. They tightened everything up, but now the height adjuster doesn't work the way that its supposed to. The dial seems like its messed up. It turns completely around rather than stopping once it has hit zero or the top setting. The numbers no longer represent the mowing height - the whole thing is screwed up. You would think that they would have tested the whole thing out properly before they delivered it back. And it still leaks down a notch when I set it at 3.5". Does anyone know anything about this improved mechanism from Kubota - part no. etc. that I can give to the dealer. I really think that they tried to fix it with the help of Kubota Canada, but if the mechanism is under designed there is not much that they can do. I use the tractor primarily for mowing - 3 grand for a mower deck, and the height adjustment doesn't work!!! If this doesn't get resolved soon, I going to be really !@#$%ed. Any help would be appreciated.

 

[RRbota]

Apparently, there are alot of people's lawns that are "pavement" smooth, with no rough spots. That's the only way I could imagine the height adjustment working as intended. It seems to work fine on BX's, but the 20 series is a different chassis. One of the drawbacks to buying a "1st year" machine, is the lack of dealer experience in solving problems like this. We, as owners, become the "testers" for the manufacturer.

I spent a couple hours yesterday, readjusting the deck (just to see if I could make it better). It seems as though the spindles are not true with each other. Side to side measurements of the deck are within spec, but I can't get the front to back the way I want it. I read in other posts (I think it was on BX 60"mmm mower settings), that you actually want the front of the blade 1/4" lower than the rear for better performance. After alot of "compromising", about the best I can come up with is left blade front to rear level, right blade front 3/8" lower than rear (can't reach center blade to measure). The left to right measurement from blade tip to blade tip is within 1/16", so that's good. Then again, if you really watch the deck while you're mowing, it's bouncing around so much, would any slight differences in measurements really make that much of a difference in mowing quality???? Even with the tractor sitting still, you can push on one end of the deck, and significantly change any blade height....temporarily. The lawn is looking good, so maybe I'm wasting my time on adjustments???? Still, I like to KNOW that I have things adjusted correctly on any of my equipment.

 

[Charlton John]

When I purchased my 2620 I originally purchased the 60"MMM also. I mowed w/ it for 10 minutes (just to check it out) yes it did mow good for this short period. But when done I really took a good look at the set up and found many of the same issues others have refered too. My height was off about an inch, the cutting adjustement dial was very wobbaly and really didnt like the set up period. Plus this was really digging into my lower linkage on the 3pt. I immidetly called the dealer and asked if he would take it back for a refund seeing it was so new. Thankfully for me he did refund the whole purchase price 2k, removed all unnecessary mower deck setup and I used the money (plus a little more out of pocket) and just purchased a nice ZTR. Just personally didnt like the set up. As far as the tractor I love it just not for mowing.

 

[jcaledon]

When new, my mower deck was adjusted perfectly, and I didn't have any issues whatsoever. I took a really good look at the mechanism on the weekend after having removed the deck, and I think I know what the problem is. The dealer adjusted the rear link, and lengthened it too much, so that the cam now hits the link when I'm adjusting the height of the mower. I could spend a ton of time trying to fix this, but the dealer will be replacing the cam, which has worn out (already) on those increments that I use most often. They can fix the rear link at that time.

The hydro whine concerns me however. They just changed the hydro fluid, and they promise me that they used Kubota S-UDT, as that is the only type of hydro fluid that they get from Kubota (that's what they said). But the tractor is now noticeably louder when under load (not the engine, just the HST).

I don't remember it being this loud when it was new. Is this normal when you change the HST fluid, and will the whine subside to how it was before? Does the fluid level have something to do with it? The fluid level seems higher than it was when the tractor was new. Isn't the whine caused by a relief valve in the HST when its under pressure. The dealer will look at this too. The tractor is terrific - it just seems that with this being a new model, service is going to be a little iffy until they learn all of the little quirks etc. with the new B series. The dealer is working with me, so I guess that I can't really complain too much, but I think I'm entitled to have it working perfectly when it only has 50 hours.

 

[Evil the Weasel]

It turns completely around rather than stopping once it has hit zero or the top setting.

The dial is supposed to keep turning in circles. Look underneath the platform at the spiral gear on the other end of the height dial. You'll see that when it goes past 4" the next spot is the lowest setting. If it's wobbly when the deck is lowered, that is definitely a problem. Mine is not wobbly, but it isn't accurate either. I'm hoping this will get a fix. And yes, my link arm is getting a little bit worn by the adapter they put on there for the deck lift. I wish it wasn't tied to the 3pt in this way. I'm hoping the snowblower lift and rotate will utilize the FEL joystick. Not sure how that is going to work yet...

 

[Charlton John]

Evil, Please let us know about the snow blower lift when received.

 

[RRbota]

Evil, are you talking front-mount snow blower?? I've got the 51" Kubota front mount snowblower and the front hitch assembly for it, but they're still in the crate yet. I obviously plan on putting them on and setting them up before we get snow. With all these mmm issues, I guess I'd better allow a bit more "test time" for the blower ! ! !

Yes, I'll agree......the mmm does do a nice job of cutting the lawn.....for now. I figure at the rate the 3-pt plate is wearing, it won't become a real problem and effect the mower's performance until shortly after the warranty expires. I guess, in this day and age, that's standard corporate design.