JD4200 w/72"MMM:Lift Problems

[Scotty370]

I purchased a JD4200 w/72" MMM. I immediateley removed the mower, and equipted the tractor with FEL & BH. This weekend I decided to mount and use the mower for the first time. I've all the mounting hardware, as it was on the tractor when purchased. Everything went well on the mounting, but I can't get the thing to lift! Mid-PTO shaft works fine. Thing runs like a top! But for this lifting problem! And, "yes" I installed the two rear lift yokes to the rear portion of the deck. Here's what I "Do" know! On my left rear rocker, for the TPH lift arm, there is a 3"dia disk this has a hole in the middle and a rod on the perimeter, that 'dives' under to seat mount to ???! This thing has a pin in it so that it definately drives the rod 'to and fro' but I: a) Have no idea was hold this disc to the the rocker arm, or b) where this arm goes after it disappears under the seat! One thing of note. The mowing level adjustment knob (by left footrest) was 'cranked' tight in the highest cutting setting. I'm in the process of loosening that up, and am wondering if the PO had this lifting problem, and just cranked the thing tight, and never moved it! Any help is appreciated! ~Scotty
Edit: I found after research that that cam/plate/rod, is a 'feed back' and not part of the lift linkage

 

[CinderSchnauzer]

Don't know about on a JD 4200 but on my JD3320 the MMM lift / lower is controlled by the 3rd SCV. The lever is either to the right or left of the 3 PTH lever to the right when sitting on the seat. On mine there are also two hydraulic couplings to the right / behind the seat. If someone has unplugged the hoses the lift won't work.

 

[Scotty370]

CS- I'm more confused than ever! After looking at the Tech Manual, I can find no linkage that goes to the bracket mounted underneath that would let it raise/lower. Three things I've done since purchase: 1) Installed Backhoe 2) Installed loader, 3) Installed 3rd SCV. Could this mower possiably be lifted by the joystick of the FEL? and because I've got the FEL on the tractor, it's taking the fluid power away from some lift arm mechanism underneath?

 

[kennyd]

The PO could have used the joystick to raise/lower the MMM, and now I assume you are using your 3rd SCV?

There should be 1 (one) cylinder on your deck with about 4' hoses on it...these need to plug into your 3rd SCV to raise/lower the deck, the big knob just set's the cutting height.

 

[Scotty370]

Perhaps I wasn't clear. There are no hydraulics associated with this mower deck at all. It's really just a 'huge' version of the one that hangs under my 318 Garden Tractor. These mowers have lift links that connect to a rocker arm under the tractor. On the 'little' guy, the hydro stick on the tractor activates the rocker arm to raise/lower. On the 4200 w/72"MMM it mounts exactly(?) the same way, but since I never used it, I don't know whether the joystick valve operates the rocker-arm underneath, or the TPH arms. Of course, now, with the loader on, pulling /pushing the joystick simply raises/lowers the bucket! I see no movement on the tractor arms underneath to lift the deck! I didn't do anything special when I bought/mounted the FEL, (spun no shutoffs, etc). Guess I'll disconect the loader QD's, and see if the 'rocker-arms' move. If it does, then I guess I can't leave the FEL on when using the mower. I don't have the book on the mower deck, but I'm sure it would just say "Connect mower lift links to rocker shaft under tractor" I've got the Tech Manuel, but can find absolutely no reference to this rocker shaft! Perhaps I'll look for "Mower Height Adjustment" It controls the distance the rockershaft lets the mower drop to. ~S

 

[kennyd]

Hmm...

I thought ALL the decks for the 42xx and up used the cylinder for lift. I have NEVER seen one that did not.

So if there is no cylinder, than there is no way the joystick is going to lift the deck...only the 3PH could be used with mechanical linkage

The 2xxx and the 4xxx series does use the 3PH for lift however, via large heavy pieces that hook one the top of the draft arms.

I have no idea what you have...I just looked on JDParts and only see the setup with the cylinder.

Can you take some pictures?

 

[kennyd]

Here is the part # for the manual, unfortunately they did not have the .pdf online...
Operator's Manual OMM136131 60-Inch (160001-), 72-Inch (170001-) Mid Mount Mowers for 4200, 4300, 4400 CUT

 

[kennyd]

Here is another picture from JDParts:

 

[Scotty370]

Boy- Now ya really got me thinkin'. (A dangerous thing indeed!) Thinking back, I wasn't there when my son pulled off the deck! I'll just bet that there's a cylinder and hoses 'kicking around here! He's in NYC right now, but I'll pick his brain at first chance! Those pics you provided sure look like my rig. Guess that would answer the question: No cylinder= no lift! Duh, Ya think! Thanks as always! ~S

 

[kennyd]

Boy- Now ya really got me thinkin'. (A dangerous thing indeed!) Thinking back, I wasn't there when my son pulled off the deck! I'll just bet that there's a cylinder and hoses 'kicking around here! He's in NYC right now, but I'll pick his brain at first chance! Those pics you provided sure look like my rig. Guess that would answer the question: No cylinder= no lift! Duh, Ya think! Thanks as always! ~S

I sure hope you find it!