1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Compressor belt on an OM366

Discussion in 'Generators/Gensets' started by Frankhaddad, Aug 29, 2019.

  1. Frankhaddad

    Frankhaddad Well-Known Member

    Joined:
    Aug 25, 2017
    Messages:
    45
    Location:
    Maine
    Mercedes engine with an air compressor mounted to it, when compressor is activated, belt bounces around violently, not activated, looks okay. have a video on my phone. belts do not last long in this condition. Any ideas would be great. Compressor is true to the other pulleys.
     
  2. MarshallPowerGen

    MarshallPowerGen Well-Known Member

    Joined:
    Nov 27, 2017
    Messages:
    71
    Occupation:
    Diesel & Generator Mechanic
    Location:
    Coeur d'Alene, Idaho
    Tensioner been replaced? Is the compressor factory, or an add on? All the pulleys been checked for any bearing play or wobble?
     
  3. Frankhaddad

    Frankhaddad Well-Known Member

    Joined:
    Aug 25, 2017
    Messages:
    45
    Location:
    Maine
    Everything is factory, This model is mounted in a Unimog large vehicle. This compressor is the only component run on this belt from the crank shaft. Adjustments are made at the compressor. Yesterday was the test after extensive work making sure everything was spot on. I have a video on my phone that I could send you. He has had a lot of pros look at it, I have 25 years experience myself, just not on Mercedes. It looks great when the compressor is off but on the belt looks like its going into a death wobble. The belt is also from the manufacturer.
     
  4. MarshallPowerGen

    MarshallPowerGen Well-Known Member

    Joined:
    Nov 27, 2017
    Messages:
    71
    Occupation:
    Diesel & Generator Mechanic
    Location:
    Coeur d'Alene, Idaho
    Yeah, I was asking generally to knock out the basics. I'm not familiar with those Mercedes engines, and especially not in Unimogs, and especially when it's an issue with a belt drive compressor in the generator section of the forum.
     
  5. Frankhaddad

    Frankhaddad Well-Known Member

    Joined:
    Aug 25, 2017
    Messages:
    45
    Location:
    Maine
    I know right! I have a reputation of being the king of funky things up here in Maine. Everything that no one can figure out comes to me. Eventually I will prevail! But this is an odd one. Could I send a vid to your email just to get another set of eyes on it? it shows at the beginning at rest, then the compressor turns on.
     
  6. Birken Vogt

    Birken Vogt Charter Member

    Joined:
    Nov 30, 2003
    Messages:
    2,799
    Location:
    Grass Valley, Ca
    Does it smooth out when the RPM is changed? Or happen at idle only? Tried changing the idle RPM either direction?

    Old Ford diesel trucks used to have a v-belt that slapped around a good bit to the alternator. They usually ran fine like this, but occasionally would jump off, but not much you could do about it.
     
    MarshallPowerGen likes this.
  7. MarshallPowerGen

    MarshallPowerGen Well-Known Member

    Joined:
    Nov 27, 2017
    Messages:
    71
    Occupation:
    Diesel & Generator Mechanic
    Location:
    Coeur d'Alene, Idaho
    I relate to that, having an '86 F350 6.9idi with the slappy alternator belt as a daily driver. You either let it do its thing, or wipe out the alternator bearings if you do ever get it tight enough to roll smooth, haha.
     
  8. Volvomad

    Volvomad Well-Known Member

    Joined:
    Jul 14, 2011
    Messages:
    231
    Location:
    Ireland
    Just because everything is OEM including the belt doesnt make it right . I would try a gates automitive (not industrial ) belt
     
  9. Frankhaddad

    Frankhaddad Well-Known Member

    Joined:
    Aug 25, 2017
    Messages:
    45
    Location:
    Maine
    I thought of an aftermarket belt, customer is very meticulous, wanted more input, thank you.
     
  10. Frankhaddad

    Frankhaddad Well-Known Member

    Joined:
    Aug 25, 2017
    Messages:
    45
    Location:
    Maine
    The belt as it turns out is a Gates belt, I was just looking at some of my pictures.
     
  11. Volvomad

    Volvomad Well-Known Member

    Joined:
    Jul 14, 2011
    Messages:
    231
    Location:
    Ireland
    A photo might help . Is it a single A section belt ?
     
  12. DB2

    DB2 Senior Member

    Joined:
    Jan 4, 2015
    Messages:
    325
    Location:
    Winnipeg MB Canada
    Is there any chance it is in fact pushing the driven pulley rather than pulling it? Or am I out to lunch here lol
     
  13. hosspuller

    hosspuller Senior Member

    Joined:
    Aug 28, 2014
    Messages:
    878
    Location:
    North Carolina
    A compressor has peaks & valleys of resistance. perhaps a less stiff belt would help to smooth the torque and the jumping. Another thought, lower the belt tension to let the rubber elements work.
     
  14. funwithfuel

    funwithfuel Senior Member

    Joined:
    Mar 7, 2017
    Messages:
    2,096
    Occupation:
    Mechanic
    Location:
    Will county Illinois
    Late to the party here. Are we talking air compressor or A/C compressor.
    I remember air compressor driving off camshaft on side of engine.