B2620 MMM Height Adjusment

[lagomasino]

I tried the 60" MMM on my new B2620 this weekend for the first time. To my dissapointment, the height adjustment knob is practically unusable. Regardless of the setting, when I lower the deck, the knob spins around and stops at 1. From looking at the other end of the knob shaft, it looks like a circular step which depending on the setting, it is supposed to prevent the deck from lowering beyond that setting, but what actually happend is that it rachets the knob all the way down.

I just talked to the dealer and he told me that there are no service bulletin for that issue, although he acknowledged that he has seen that problem in other tractors and has had to grind the notches on that circular step piece at the other end of the knob.

I was wondering if anyone else has experience the same issue in the B2x20 models and how you had it resolved. Thanks in advance

 

[mtrain]

Yes we've seen this problem and just as your dealer stated, there is a service bulletin in regards to how to repair it. Have the dealer fix it as a warranty repair.

 

[Charlton John]

I tried the 60" MMM on my new B2620 this weekend for the first time. To my dissapointment, the height adjustment knob is practically unusable. Regardless of the setting, when I lower the deck, the knob spins around and stops at 1. From looking at the other end of the knob shaft, it looks like a circular step which depending on the setting, it is supposed to prevent the deck from lowering beyond that setting, but what actually happend is that it rachets the knob all the way down.

I just talked to the dealer and he told me that there are no service bulletin for that issue, although he acknowledged that he has seen that problem in other tractors and has had to grind the notches on that circular step piece at the other end of the knob.

I was wondering if anyone else has experience the same issue in the B2x20 models and how you had it resolved. Thanks in advance

Also do a search in this thread about 2620 MMM adjustment knobs there were many threads about this issue and how some have fixed the problem.

 

[lagomasino]

Thanks, I found that this issue has been adddressed under the "B2X20 MMM height adjuster" thread. What I am still not clear is about whether there is an official Kubota fix for this problem. My dealer said that there is NO service bulletin on that issue. He acknowledged seeing that problem and having it fixed by himself, but nothing official from Kubota. I get the impression from the other thread and the previous response that there is a Kubota fix. Does anybody have details on whether an official service bulletin for this issue on the B2X20 models exist?

My dilemma about this issue is that the tractor is now located in a very remote place in WV. Taking it back to the dealer I bought it from is a long trip (200 mi). Taking it to the nearest dealer is 45 miles one way. If it is a known service bulletin, any dealer should be able to fix it. I rather drive the 45 miles.

Very frustrating

 

[Evil the Weasel]

When I first got mine delivered, the deck had two settings: scalping and all the way up. Yep, it was adjusted wrong. They rolled it back to the dealership and it's working fine now. The blade height is off by just under 1/2" on any of the dial settings which is close enough for me. The adjusters on the lift arms are screwed in more than the manual says they should be, but the manual has other errors in it too.

 

[lagomasino]

I found some really nice pictures posted by RRbota on a somewhat unrelated thread "Anyone put Kubota's front quick hitch on their new B yet??"
This is quite an elaborate and carefully thoughtout fix.

 

[Evil the Weasel]

I saw that too, but it wasn't necessary for my situation.

 

[mtrain]

I stand corrected. It wasn't an actual service bulletin. It was a top product issue listed in the Kubota dealer's online service center. See this attachment

mtrain

 

[sedmond]

I've had my B2920 for almost a year without any problems with the mower deck adjustment. Until a couple of weeks ago when the deck starting jumping to lower settings. I found that I had to hold onto the adjustment knob and then slowly lower deck to get it to catch at correct height. And then try to avoid bumps which would make it bounce to a lower setting. I looked underneath and don't appear to have any sideways play in the link shaft as discussed in previous articles. There is a lot of play in the knob's shaft, but not much more that there always has been. Anyway, dealer is picking up tractor tomorrow to repair under warranty.

 

[lagomasino]

sedmond, That's exactly how I have to operate the MMM for now until I have the opportunity to take the tractor to the dealer. Unfortunately in my case, it is a long haul. The dealer told me to bring the knob assembly (the part that has the piece that looks like a circular step) and that they will fix that assembly.

 

[CHDinCT]

sedmond, That's exactly how I have to operate the MMM for now until I have the opportunity to take the tractor to the dealer. Unfortunately in my case, it is a long haul. The dealer told me to bring the knob assembly (the part that has the piece that looks like a circular step) and that they will fix that assembly.

Can you have your dealer ship you a modified shaft assembly, maybe off of a new on-the-lot unit, then ship yours back so he can modify it an put in on the unit he took one off of? This assumes it's not too hard for you to get at the shaft for removal and reinstallation.

 

[lagomasino]

Sounds like a good idea. Otherwise, the tractor will be out of comission for a couple of weeks and the grass will get out of control. Thanks!

 

[lagomasino]

I finally took the assembly that holds the MMM at the proper height to the dealer. They will install a new spiral cylinder with enhanced (grinded) notches. They are also straightening out the lever that engages on the notches so that it engages at the outer edge of the spiral cylinder. Basically bending it out. The shaft did not have any side-play as others has reported, so they had to bend it.

The main problem was that the lever was engaging too close to the center of the cylinder and at that point, the notched are not that deep.

I know this description is kind of cryptic. I'll post a picture of the assembly when I get it back (this Wednesday) and post the results.

 

[Evil the Weasel]

I hope this works out well for you. I have not had the problem with the deck height slipping. I do know that the height adjuster is the same part used on some BX models so it was not engineered specifically for the new B's.

 

[PUSHINDIRT]

I'd like to see what the new piece looks like. I bought my 60" and will finally be getting around to installing it this weekend (grass is getting a bit tall). If my control knob needs to be fixed, hopefully I can do it before I put it on the tractor and save myself the hassle of taking it off later.

 

[mtrain]

See post #8

 

[lagomasino]

I got the parts back today. Here what they did:
1) New parts - the stepped cylinder and the shaft
2) Grinded down the steps in the cylinder to enhance the steps
3) Straighten the lever that engages on the step to align it
4) Grinded the top of the stepped cylinder so that the knob is not wobbly

It looks like it is going to work better with this improvements. We'll see when I mount the assembly on the tractor and put the MMM back. Attached are some pictures of the new and old shaft and of the wohle assembly.

I will report back how it all works.

 

[rrluczak@comcast.net]

Hi, I have the same problem when I mow over an uneven lawn (river bank and field) the dial bounces out of adjustment to the point that the cam surface worn smooth. What I did to fix the problem was have the dealer replace the cam and order a second cam spring (Kubota calls it a plate retainer) and I installed two springs together. (old selectric typewritter repair trick) along with a plastic washer I cut from a coffee can lid to fit between the cam and the cam base, This removed all play from the shaft and by adjusting the cam nut until the knob was allmost too tight to turn, has fixed this so far... PS don't try to bend the cam spring, I will snap before it bends.

 

[michaelb3]

I've got a year old b2920 with the 60" deck and the mmm has never been able to raise high enough to get the pins in towards the front to support the deck when it's all the way up.
My dealer at the time of delivery "insinuated" this was a design flaw and that there were obstructions under there that prohibited things from getting to be aligned. Has anyone had any luck with this?

 

[jcaledon]

I've got a year old b2920 with the 60" deck and the mmm has never been able to raise high enough to get the pins in towards the front to support the deck when it's all the way up.
My dealer at the time of delivery "insinuated" this was a design flaw and that there were obstructions under there that prohibited things from getting to be aligned. Has anyone had any luck with this?

Michaelb3,

In short, this is bull. When my B2620 was first delivered, the MMM adjustment worked well, but I was never able to pin it up. I returned the unit to the dealer to address this issue and to do the 50 hours service. They had a very hard time adjusting the deck. In fact, they had to have a Kubota technical rep come out to the dealership to assist them with the necessary adjustments so that it could be pinned up. Additionally, they made some adjustments to the cam, and everything now works as advertised. The only problem that they were not able to address 100% completely was matching up the height of the adjustment dial to the actual cutting height - it's off by a quarter inch. So when I set the dial to 3", its actually cutting at 2 and 3/4 ". Not a big deal for me - this may have more to do with the fact that I have mulching blades on the deck as opposed to the stock blades.

The B is an excellent mower. The new drive over mower deck has caused a lot of headaches for people because it is not easy to adjust, and more importantly, because IMO the dealers have not been trained thoroughly enough in how to set them up. Hopefully, as more and more of these machines are sold, the knowledge of the techs will improve so that new owners of the B20 series will not have to experience the same teething issues that I and many others have.