Results 1 to 4 of 4
  1. #1
    Bronze Member
    Join Date
    Jul 2006
    Posts
    72
    Tractor
    John Deere 2520

    Default John Deere 2520 - Rear PTO & Rear Implement Shaft Overlap

    Hello guys,

    I recently converted my Bearcat 73554 Chipper/Shredder over to be compatible with my I-match hitch. By doing so put the unit back about 4-5". Right now I am only getting about 2 1/4" - 2 1/2" overlap of my PTO shafts. The book does not state what this length should be, only that the distance between the two shafts should be 24 1/2" or less, and if not contact my dealer and get a longer shaft.

    Since this is my first implement with a rear PTO drive shaft, and I am well over the 24 1/2" as you'll see in the pictures, I am looking for some of you with more experience to tell me if they know this will be fine or destined for failure. I have about 3 hours on the machine now with the stated overlap and no problems yet.
    John Deere 2520 w/R3's
    200CX FEL - 61" bucket & 48" Frontier AL1240F Forks, 72" MMM, Hyd. Dump MCS, Bearcat 73554 PTO Chipper/Shredder, 54" Quick Hitch Front Mt. Snow Blower

  2. #2
    Gold Member
    Join Date
    Jun 2007
    Posts
    425
    Location
    Northern West Virginia
    Tractor
    JD

    Default Re: John Deere 2520 - Rear PTO & Rear Implement Shaft Overlap

    I think you're asking for trouble. I recall the manual for one PTO shaft I have stating clearly that the overlap should be 1/3 the total length of the shaft. The Bush Hog manual says at least 6". That seems reasonable to me. Your 2-1/2" seems way too short to me. I wouldn't want to be around if that joint starts to buckle at 540 RPM.

    True, there's no reason for it to have lateral stress....unless something is a little off balance, or a little off center, the joint wears and becomes off center, etc...

    The power of your tractor is transmitted from the PTO to your chipper through the overlap. If your overlap is a lot shorter than it needs to be, then the wear on that overlap will be much greater than it should be. A little wear, things start loosening up, the shaft is not centered any more, and then the power of your tractor is whipping half of a PTO shaft around at 540 RPM....

    You've got the added concern that you'll be near the PTO driving your chipper. It's not like you're using this PTO on a brush hog behind you.

    My recommendation is to get the right length PTO, and try to sell yours through your local "bulletin board" paper or on EBay.

  3. #3
    Super Star Member RoyJackson's Avatar
    Join Date
    Nov 2001
    Posts
    19,344
    Location
    Bethel, Vermont
    Tractor
    John Deere 4520 MFWD, Deere 855D UTV, Z920A Zero Turn Mower and assorted implements

    Default Re: John Deere 2520 - Rear PTO & Rear Implement Shaft Overlap

    Another thought is to get a PTO Extender, depending on how "well over" the 24.5" you are.
    You can buy these at Tractor Supply and online.
    Roy Jackson

    "Any government that does not trust its citizens with firearms is either a tyranny, or planning to become one."
    -Joseph P. Martino

  4. #4
    Silver Member
    Join Date
    Jun 2007
    Posts
    155
    Location
    Madison, WI
    Tractor
    John Deere 790

    Default Re: John Deere 2520 - Rear PTO & Rear Implement Shaft Overlap

    Seems to me this is a case of "the more the better". It's not like a mower or tiller, where you'll be running the PTO while driving the tractor and implement over uneven terrain. In those cases, you can be sorry with either too much or too little overlap. But with a chipper, I would def. go for as much overlap as you can manage, and indeed, at least 6". The "one-third" rule, BTW, means 1/3 of _either half_ of the shaft. Once you put it together (do the math), it translates to 20% of the overall shaft length. So for your 32"-ish overall length, I'd go for 6-7" of overlap minimum.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.