OT- How do you size hydraulic cylinders?
Close
Login to Your Account
Results 1 to 12 of 12
  1. #1
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    2,418
    Post Thanks / Like
    Likes (Given)
    179
    Likes (Received)
    954

    Default OT- How do you size hydraulic cylinders?

    I have a backhoe attachment for my IH tractor and I broke the hydraulic cylinder on the bucket this weekend. What happened was the clevis pin came out and it put too much side force on the piston rod. The rod is chrome plated cast steel I think and it just snapped right in half. It obviously can't be fixed so I need to find a replacement. I know the piston rod is 1.5" in diameter but I can't see the bore. The outside dimension of the cylinder is 3" so the bore can't be 3" but something less then that depending on the thickness of the cylinder walls. For you guys out there who work on a lot of this kind of thing, do you think I could assume that the "bore" is 2.5"? That would mean I would need a 2.5" bore 18" stroke cylinder with a 1.5" rod. Whatever I get I will probably have to bore out the clevis. From what I have seen on line in that range the clevis pins all seem to be 1". On this cylinder the clevis pins are 1.5" and the clevis hole is larger then that because there is a wear bushing in the clevis that looks like it may have a .250" wall thickness. Thanks for any help.

  2. #2
    Join Date
    Dec 2000
    Location
    Bremerton WA USA
    Posts
    10,704
    Post Thanks / Like
    Likes (Given)
    41
    Likes (Received)
    4343

    Default

    Something like this?

    Surplus Center - 2.5X18X1.5 DA HYD CYL 1 PINS HVY DUTY CROSSTUBE

    $175 but getting the end fittings, the closed length, connections, etc right might be a problem. Can the cyl you have be repaired? A new rod is a common fix.

    If local ag equipment repair shops are no help, look in the yellow pages for a local hydraulics shop. Otherwise Google "hydraulic cylinder" and start winnowing.

  3. #3
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    2,418
    Post Thanks / Like
    Likes (Given)
    179
    Likes (Received)
    954

    Default

    Hi Forrest, I had not thought of a new rod. I will look into this. Thanks again.

  4. #4
    Join Date
    Feb 2007
    Location
    aurora ohio
    Posts
    1,128
    Post Thanks / Like
    Likes (Given)
    81
    Likes (Received)
    197

    Default

    Cross thread, If you have access to a lathe, Hyd. rods are not hard to make, Chromed stock can be purchased from many hydraulic repair places, just a matter of cutting to length,and threading both ends.
    I repaired a neighbors back-hoe last year, The steering cylinder was over $1700.00 from
    Ford, and un-obtainable. I took it apart, bought some chrome stock from AKRON HYDRAULICS, made the shaft, and put in new packing for under $35.00.
    The shaft was a lot smaller, 1" x 12" , But they sold chrome stock by the dia x inches of length. They also had metric dia's.
    Hardest thing was getting out of the guys shop, He wanted to know what I was going to do with the chrome shafting, When I told him, He wanted to hire me to make shafts in his shop.
    Use carbide to get under the chrome, then thread normally. Dave [acme thread]

  5. Likes S_W_Bausch liked this post
  6. #5
    Join Date
    Jul 2004
    Location
    Asheville NC USA
    Posts
    8,876
    Post Thanks / Like
    Likes (Given)
    3632
    Likes (Received)
    3025

    Default

    The rod will normally be 1045. Some are induction hardened on the surface while other cylinder rods aren't hardened.

    Bailey in Knoxville TN has a big stock of chromed rod, both hardened and soft, if you don't have a closer source. They also have a wide range of cylinders in stock in various configurations and lengths. You'd need to take the rod seal gland off your cylinder to check the bore size if you decide to go with a new cylinder.

    Bailey Hydraulic Cylinders Manufacturer

  7. #6
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    2,418
    Post Thanks / Like
    Likes (Given)
    179
    Likes (Received)
    954

    Default

    Yes Acme I do have a lathe and milling machine. I did not know of this option either. In your opinion would there be any special procedures I should follow when I weld the clevis ends back on the chrome rod? I would not think there would be a huge amount of warping but never having done this I have no experience. Metlmunchr, you say the rods are probably 1045. Is this cast? The reason why I ask is that when this rod snapped it broke like cast iron would. It is definitely a crystalline structure and probably very brittle.

  8. #7
    Join Date
    Mar 2009
    Location
    Brunswick Oh USA
    Posts
    4,555
    Post Thanks / Like
    Likes (Given)
    5143
    Likes (Received)
    2717

    Default

    Crossthread,
    I make these things all the time. No, 1045 is just somewhat of a high carbon steel. It will show a crystaline structure when broken. They use this for rods most of the time. It can also be hardened. Don't buy the hardened stuff. You can't machine it. I always buy: .001 chrome w/ 100k tensile strength. Here's a tip for you. When I need to put an eye end or clevis end on a rod, I chamfer the rod for weld, and depending on rod dia. I'll drill and tap a ¼ to ½'' thread in the end of the rod, as well as the clevis end. Put a set screw in either piece and screw them together. Nice and square and ready for weld. Piece of cake! I'd use a 5/16" setscrew on your app.

  9. Likes Cole2534 liked this post
  10. #8
    Join Date
    Aug 2004
    Location
    Winchendon, MA USA
    Posts
    804
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    231

    Default

    The only thing that I can add is if the rod went side ways enough to snap off if also probably put a reverse dent in the cylinder, so you need to disassemble the cylinder and do some fussy measuring in the barrel and you will probably find a swelling, or a gouge where the piston pressed against the side of the barrel.

  11. #9
    Join Date
    Aug 2004
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    2,418
    Post Thanks / Like
    Likes (Given)
    179
    Likes (Received)
    954

    Default

    Thanks guys, again great information as this is something I have never gotten into before.

  12. #10
    Join Date
    Mar 2009
    Location
    Brunswick Oh USA
    Posts
    4,555
    Post Thanks / Like
    Likes (Given)
    5143
    Likes (Received)
    2717

    Default

    A few more things to be aware of: Make sure your chuck jaws are clean and smooth. If not, they will impart their gouges and dings to the chrome bar. The chrome is hard, but the metal under it, is not. Also, always single point the workpiece. If you try to do it with a die (yuck), the chrome will spin in the chuck and ruin it. This stuff is slippery and cannot be held tight enough to avoid this. You can tighten the chuck a damn good amount, but don't be a gorilla. And another thing! Take light enough cuts, so as not to push the bar through the chuck. Just another way of ruining it. Ask me how I know! Getting through the chrome is no sweat, but breathing the dust it creates is no good.

  13. #11
    Join Date
    Jun 2008
    Location
    Roanoke, VA
    Posts
    672
    Post Thanks / Like
    Likes (Given)
    192
    Likes (Received)
    253

    Default

    When we design a cylinder that will be loaded in tension, the eye is always threaded onto the rod with a thread large enough to fully support the load w/o weld. Where the eye is a tube welded perpendicular to the rod, I have seen the tube crack off on more than one occasion when the actual loaded differed than the assume loading.

    You will have to remove the head gland to get the rod out, I would measure the bore size in case you need to order a replacement cylinder at that time.

  14. #12
    Join Date
    Feb 2007
    Location
    aurora ohio
    Posts
    1,128
    Post Thanks / Like
    Likes (Given)
    81
    Likes (Received)
    197

    Default

    Crossthread, With an International backhoe, Your in the economical area of my expertise.
    If the clevis is welded to the end of the rod, just bevel the shaft for a good weld, and pour the 7018 to it. This is done last , after threading the piston end. Wrap the shaft with some asbestos[ I know a good farmer has some stashed somewhere]; So you don't spatter up the chrome. I've done several, and haven't had any returns. I even rewelded
    a Ford outrigger cylinder clevis back on, without removeing the cylinder from the machine, Thats been a good ten yrs., and she's still hoeing around.
    This isn't rocket science, No sense in putting $500.00 into a new cylinder. It won't make the machine dig any better or improve it's value.
    Just remember to buy new seals ,wipers and packing, probably from the hyd. shop where you buy the shafting. Hydraulic oils like gold anymore.
    Dave [acme thread]


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •