Learned something earlier this week that might help someone else. When I first got the tractor home, I noticed it cut far to low for my liking on the highest setting. The operator's manual outlines the deck adjustment procedure, so I followed it - and the mower was still far to low. So I remove the deck and slide under the tractor for a closer look. There is a linkage connection between the mid lift and the rear lift - notice the three bolts attached to the linkage:
The above linkage can be easily accessed from the left rear of the tractor:
Raise the lift fully. Loosen the three bolts on the linkage with a 5/8' wrench. If you have help available, have your assistant lift the Auto Connect coupler assembly to maximum height and hold it steady while you re-tighten the bolts. You might be able to do this by yourself if you disconnect the Auto Connect coupler assembly and push the mower lift link - it may stay in the full height position without the weight of the Auto Connect coupler assembly pulling it down. I don't know for sure since I had my son there to help.
Here are some more photo's that may be helpful:
Above photo is the MMM Auto Connect coupler assembly in the "Install" position.
The next photo below is the "Height of Cut" adjustment as viewed from the underside of the tractor in the "Install" position. Note the position of the mower lift link in the cam:
The next photo is of the "Height of Cut" adjustment as viewed from the underside of the tractor in the "Lock" position:
Here's the "Height of Cut" knob. It won't turn completely to the "Lock" position for some reason. When I get time, I'll see if I can figure out why and adjust it as well:
MMM adjusted to full cutting height - much better: