Page 1 of 2 12 LastLast
Results 1 to 10 of 14
  1. #1
    Bronze Member simonds's Avatar
    Join Date
    Nov 2010
    Posts
    86
    Location
    Steuben Co. N.Y.
    Tractor
    John Deere 4200

    Default 4200 Hydrostatic positive lock won't engage completely

    1999 JD 4200 hydrostatic. Positive lock differential petal won't lock in completely. I can feel it going in and out while holding the petal down. I don't find any adjustment on it. Any help out there? Thank you.

  2. #2
    Super Star Member
    Join Date
    Aug 2001
    Posts
    13,866
    Location
    Upper Midwest USA
    Tractor
    JD_4x2_Gator, JD_4300, JD_X485, JD_425, JD_455, JD_110

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Look at the linkage on jdparts.com and see if you can decipher where the problem might lie. Might be something broken.

  3. #3
    Advertiser kennyd's Avatar
    Join Date
    Jul 2003
    Posts
    12,675
    Location
    Westminster, MD
    Tractor
    John Deere 4110, 455AWS

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Here are the two breakdowns from JDP, if you can "feel it going in and out" then I'm afraid it might be internal.:

    4200 Hydrostatic positive lock won't engage completely-4200-1-gif\


    4200 Hydrostatic positive lock won't engage completely-4200-2-gif
    KennyD
    www.boltonhooks.com

    #BoltOnHooks



    Bolt-On Grab HooksTM, Bolt-On Clevis MountsTM, Weld-On Grab Hooks, Specialty Chain and Rigging Accessories, Specialty Hydraulic Components, and MUCH more!

    Visit our YouTube Channel

  4. #4
    Bronze Member simonds's Avatar
    Join Date
    Nov 2010
    Posts
    86
    Location
    Steuben Co. N.Y.
    Tractor
    John Deere 4200

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Thank you for the replies. I'll check it out further.

  5. #5
    Member
    Join Date
    Aug 2015
    Posts
    46
    Location
    Pasadena, MD
    Tractor
    JD 4400

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    I just started tearing into my 4300 to fix the diff lock. I bought it that way and from what I'm told the lock itself is a cast piece which is prone to breaking if engaged after one wheel is already spinning. A school had used it to plow sidewalks so it probably did a fair bit of spinning if the new guy forgot to engage 4x4. The pedal moves fine but doesn't do anything. The part is between $100-150 from memory, but lots of hours to replace it. According to the manual have to remove the right final drive and the 3 point rock shaft assembly. Hoping to get the old one remove this weekend, can let you know how it goes.

  6. #6
    Super Member dfkrug's Avatar
    Join Date
    Feb 2004
    Posts
    5,340
    Location
    NorCal
    Tractor
    05 Kioti CK30HST w/ Prairie Dog backhoe

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    One side of the diff-lock mechanism is soft cast steel; the other is harder/tougher steel.
    So the former wears a lot when rubbing against the latter. If there is enough meat left
    on the cast part, then you can shape it with a grinder to make it grab better, as I
    did for one of my 4300s.

    Otherwise, you are gonna have to buy the whole ring and pinion set. $$$$
    Attached Thumbnails Attached Thumbnails 4200 Hydrostatic positive lock won't engage completely-dlock4-jpg   4200 Hydrostatic positive lock won't engage completely-dlock3-jpg   4200 Hydrostatic positive lock won't engage completely-dlock5-jpg   4200 Hydrostatic positive lock won't engage completely-dlock6-jpg   4200 Hydrostatic positive lock won't engage completely-dlock7-jpg  

    4200 Hydrostatic positive lock won't engage completely-dlock7a-jpg  

  7. #7
    Member
    Join Date
    Aug 2015
    Posts
    46
    Location
    Pasadena, MD
    Tractor
    JD 4400

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Quote Originally Posted by dfkrug View Post
    One side of the diff-lock mechanism is soft cast steel; the other is harder/tougher steel.
    So the former wears a lot when rubbing against the latter. If there is enough meat left
    on the cast part, then you can shape it with a grinder to make it grab better, as I
    did for one of my 4300s.

    Otherwise, you are gonna have to buy the whole ring and pinion set. $$$$
    Wow, great pics! I'm assuming you're holding a new piece in the second pic? What did the original one look like?

  8. #8
    Super Member dfkrug's Avatar
    Join Date
    Feb 2004
    Posts
    5,340
    Location
    NorCal
    Tractor
    05 Kioti CK30HST w/ Prairie Dog backhoe

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Quote Originally Posted by texasranger556 View Post
    Wow, great pics! I'm assuming you're holding a new piece in the
    second pic? What did the original one look like?
    That IS the original piece. I just reshaped it with a die grinder and an angle grinder.

  9. #9
    Member
    Join Date
    Aug 2015
    Posts
    46
    Location
    Pasadena, MD
    Tractor
    JD 4400

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Quote Originally Posted by dfkrug View Post
    That IS the original piece. I just reshaped it with a die grinder and an angle grinder.
    I mean the smaller piece in your hand in pic 2 (not with the arrow), it looks like you ground the ring/pinion side.

  10. #10
    Super Member dfkrug's Avatar
    Join Date
    Feb 2004
    Posts
    5,340
    Location
    NorCal
    Tractor
    05 Kioti CK30HST w/ Prairie Dog backhoe

    Default Re: 4200 Hydrostatic positive lock won't engage completely

    Quote Originally Posted by texasranger556 View Post
    I mean the smaller piece in your hand in pic 2 (not with the arrow),
    it looks like you ground the ring/pinion side.
    Yes. Only the part attached to the ring gear was reshaped. It was an error on JD's part to use
    such a soft steel as part of the diff-lock dog clutch.

    It seems to work OK after this repair. No new parts were purchased.

Page 1 of 2 12 LastLast

Similar Threads

  1. jd 2000 hydrostatic 4200 compact track will not start help
    By srescobar in forum John Deere Owning/Operating
    Replies: 0
    Last Post: 10-03-2013, 09:52 PM
  2. TC33D: Can't Engage Differential Lock
    By barbque5 in forum Parts/Repairs
    Replies: 2
    Last Post: 01-16-2013, 11:37 AM
  3. 4200 hydrostatic low range only
    By greenie in forum John Deere Owning/Operating
    Replies: 8
    Last Post: 11-18-2010, 07:30 PM
  4. 4200 Collar Shift Differential Lock
    By U2DEERE in forum John Deere Owning/Operating
    Replies: 4
    Last Post: 03-29-2006, 06:05 PM
  5. posi lock wont engage
    By titan307 in forum Parts/Repairs
    Replies: 6
    Last Post: 06-24-2005, 12:29 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2016 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.