1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

UniMount shudder

Discussion in 'Western Plows Discussion' started by SnowMatt13, Jan 8, 2016.

  1. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,535

    Plow angles perfect right/left if you have a pause between function selection on the control. If you are angling right and immediately hit the left button it shudders as it angles left....almost like it is hitting air pockets.
    Any thoughts??
     
  2. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,643

    Try wiggling the connection on the front of the truck, 9 pin plug.

    Almost sounds like your connection is not good.
     
  3. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Sounds like a resonation vibration. I would like to ask when is the last time you changed your fluid? I would also look at the amount of wear in your pivot pin hole and the ram pins. So many possibilities and so little information. What kind of plow is it? Uni, ultra, cable plow? Straight blade, wide-out, MVP???
     
  4. Randall Ave

    Randall Ave 2000 Club Member
    Messages: 2,049

    He has in his caption its a Unimount. I had one like this years ago. Ended up replacing the valve block. Could not take it apart as the block was rotting apart. I had a good used one. I never throw out anything. Not saying this is the problem, but it fixed that one.
     
  5. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Yes I see now the thread title says uni so now we know for sure it's old.... Could be a lot of things, loose electrical connections, bad coils, bad valves. But I don't suppose he has a good valve block floating around he can swap in.
     
  6. Dogplow Dodge

    Dogplow Dodge PlowSite Veteran
    from NJ
    Messages: 3,040

    Unimounts are so easy to rebuild, It's hard to believe that he just doesn't buy a rebuild kit and go to town..

    I'm slow and I can rebuild a pump in about 3 hours. Takes longer to take it apart and clean all the parts than it does to put it back together. Everything you need (instructions) are on Western's website in the owners / repair manual section. Rebuild kit runs about $150 or so, and as long as you don't need hoses, pump or new ram, you're good to go with new fluid, although I do recommend replacing the hoses, and flushing out the angle rams.
     
  7. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,535

    9 ft unimount straight. New quadrant and pivot bolt last year. Fresh western fluid in november. Brand new truck side wiring complete this fall. Will check out above mentioned and report back. Thanks for suggestions!
     
  8. Randall Ave

    Randall Ave 2000 Club Member
    Messages: 2,049

    When I go to the scrap yard I always ask about used units. If they have any you can get them for next to nothen. Its nice to have some spare parts.
     
  9. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    If I didn't live in town and have anal neighbors I would have a whole junk yard of old plows in my back yard! Spare parts are great to have.

    Since there is no doubt about the quality of the pivot points then it has to be electrical or hydraulic. It could be a loose connection that is making and breaking the circuit to a valve.

    I would be tempted to put a test light on the valve coil / coils that are active when is shudders and see if the test light flashes or not. Perhaps you have a friend with a truck you could test it on. If it only does it on your truck then you know it has to be in the control wiring. My guts say it's electrical. Sticky valves wouldn't open and close like this, they would just not open fully and make it slow.

    I have to ask if you have verified the basics... Is the fluid level topped up? Air in the lines can make it shudder but if the reservoir is full it will purge out any air in just a few cycles of operation.
     
  10. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,535

    Back with some answers.
    Changed all 3 cartridges as a local Western tech led us to that conclusion. I just did all 3 instead of 2. Put back together and have the same issue.
    Swapped the plow with another truck and the issue followed the plow so it has to be in the unit or the plow side wiring.
    Rebuild the unit or change the plow side wiring are my next 2 options.....
     
  11. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Before you rebuild or spend more money consider cheching all angle related movement points for mechanical drag. Remove the two angle hoses from the valve body, jack the plow blade up a bit and push the blade from left to right extremes. Feel for any mechanical drag. Could be a bad ram or something like that. KISS keep it simple stupid.... It has to be some thing simple.
     
  12. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,535

    And the winner is.....right angle cylinder. Packing set was bad. Rebuilt the left one first with the intention of doing them both....