B2620 MMM Height Adjusment

[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.