Hydrashift changing gear problems
Close
Login to Your Account
Likes Likes:  0
Results 1 to 8 of 8
  1. #1
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    2

    Default Hydrashift changing gear problems

    shift to the higher speeds
    Last edited by skipjackbill; 04-02-2020 at 11:19 PM.

  2. #2
    Join Date
    Jul 2017
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    170
    Post Thanks / Like
    Likes (Given)
    17
    Likes (Received)
    36

    Default

    Perhaps some more information would be helpful in trying to diagnose the problem.
    * Will the machine shift into the higher speeds at all?
    * Does it make a difference if you manually jog the spindle by hand?
    * Any new or unusual noises?
    * Is the headstock hydraulic fluid at the correct level, and of the correct type? When was the last time the fluid was changed?
    * Have you removed the headstock cover and visually inspected inside for problems, and manually checked the movement of the pistons/forks/gears?

    If the primary hydraulic pump is worn, you may need to wait until the spindle comes to a complete stop, then rotate the gear change knob on the front of the headstock to select the next gear, then wait a few seconds (you can sometimes hear the hydraulic pressure inside the headstock spool up until it has enough uumph to shift the gears).

    If there are no obvious mechanical problems (stuck piston, broken gear, etc.), you'll want to check the setting of the hydraulic relief valve inside the headstock per the factory manual.

  3. #3
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    2

    Default

    Thank you Elwood for the reply now to address the questions
    1. Yes it will select the highest speed 1450 and the next highest speed 545 then it goes to 51 and finally 37 but it will not shift to 1045 and 777.
    2. I have tried jogging the spindle over and over in all combinations but no change
    3. When I try to select either of the speeds that it will not engage it has the sound of the the hydraulics shifting but does not engage.
    4. I had just changed the hydraulic fluid and cleaned the filter using Mobile DTE Medium . But I did discover that the manual calls for DTE light so I called Glaseen Oil to see if that could make a difference Tom did not think so.?? Oil is at the level on the sight gauge.
    5. Today I did remove the cover and was expecting to find something amiss but found nothing actually looks very clean.
    About the gear change dial when I have it on and set to either of the two speeds that doe not engage I can not turn the dial easily with out turning the machine off then it will move freely.
    I have read on the pressure test to but I did not feel comfortable to try the test with out more reading . When I had the cover off
    I engaged the select knob I got a burst of Hydraulic oil for a split second.
    If you can suggest anything that might help solve this issue I greatly appreciate it

  4. #4
    Join Date
    Jul 2017
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    170
    Post Thanks / Like
    Likes (Given)
    17
    Likes (Received)
    36

    Default

    I'd want to verify that the hydraulic system is at the correct pressures first. If you have a gage with the correct range and the right fittings, the test is actually simple and easy to do.

    Using the heavier DTE Medium probably isn't causing your problem, but longer term, especially if your shop gets cold, I'd want the thinner DTE Light.

    When the spindle is turning in any of the functioning speeds, do you see oil flow through the oil sight gage in the headstock?

    When you had the headstock cover off and changed speeds, where did the burst of oil come from?

    The difficulty in turning the shift knob in the two speed positions sounds like there's pressure in the hydraulic system, as if the shifts aren't completing.

    It's not unheard of for these Hydrashifts to develop sludge or varnish in the piston bores of the hydraulic shift block, especially if the maintenance has been neglected or the machine sits unused for long periods of time. When I disassembled the shift block on my 12-1/2 Hydrashift, I found sludge in the ends of the bores, on the removable head plates. If there's enough stuff in there, it might be restricting the full travel of the piston.

    Remove the headstock cover, and with the motor off, try shifting each of the three fork/piston assemblies through their full range of motion. You may have to jog some of the gears by hand to get them to engage as you move the shift fork/piston. Note that the "B" shaft has two grooves for a ball detent, so it may be harder to move out of those two positions.

  5. #5
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    2

    Default

    Quote Originally Posted by Elwood1968 View Post
    I'd want to verify that the hydraulic system is at the correct pressures first. If you have a gage with the correct range and the right fittings, the test is actually simple and easy to do.

    Using the heavier DTE Medium probably isn't causing your problem, but longer term, especially if your shop gets cold, I'd want the thinner DTE Light.

    When the spindle is turning in any of the functioning speeds, do you see oil flow through the oil sight gage in the headstock?

    When you had the headstock cover off and changed speeds, where did the burst of oil come from?

    The difficulty in turning the shift knob in the two speed positions sounds like there's pressure in the hydraulic system, as if the shifts aren't completing.

    It's not unheard of for these Hydrashifts to develop sludge or varnish in the piston bores of the hydraulic shift block, especially if the maintenance has been neglected or the machine sits unused for long periods of time. When I disassembled the shift block on my 12-1/2 Hydrashift, I found sludge in the ends of the bores, on the removable head plates. If there's enough stuff in there, it might be restricting the full travel of the piston.

    Remove the headstock cover, and with the motor off, try shifting each of the three fork/piston assemblies through their full range of motion. You may have to jog some of the gears by hand to get them to engage as you move the shift fork/piston. Note that the "B" shaft has two grooves for a ball detent, so it may be harder to move out of those two positions.
    Thanks for your guidance I will take the top off and do the test and will send pictures . There is an aluminum block on top by the the forks that has a set screw with a jamb nut and I assume it is the pressure adjustment and at one end of the block it has a brass fitting that is not connected to anything and think that is where the spurt of oil came from.

  6. #6
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    2

    Default

    Attachment 283998Here is a picture of the head stock , when doing the pressure test as the manual describes
    the pressure jumps up to over 300lb and then relieves and that is where I get the short spurt of oil . I tried to adjust the relief valve but does not change . I inspected the valve but could not see anything that would cause a malfunction. I did find the that adjustment screw would only move 1 1/2 turns from full closed to full open ? Not sure what to do nextimg_e1502.jpg
    Last edited by skipjackbill; 04-05-2020 at 08:24 PM.

  7. #7
    Join Date
    Jul 2017
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    170
    Post Thanks / Like
    Likes (Given)
    17
    Likes (Received)
    36

    Default

    Were you able to manually cycle each piston/shift fork through the full range of travel (with the motor off)? By full range, I mean complete engagement of the gears at each end of the piston/fork travel.

    When the spindle is turning (motor running in any gear) can you see oil flow in the sight glass? It's easier to see in the higher speeds.

  8. #8
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    2

    Default

    Hi Elwood. I have tried figure out where the shifting forks are supposed to be for each speed . I was wondering if I took pics
    of each setting and what gear my dial is in would you be able to tell me which ones are in the right place ? I can move all the forks just don't know what speed there in and if they are in the right position, And yes oil is running down the sight gauge


Tags for this 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
  •