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!

clutch brake adjustment

Discussion in 'Trucks' started by 06bowtie_guy, May 31, 2009.

  1. 06bowtie_guy

    06bowtie_guy Well-Known Member

    Joined:
    Jan 18, 2007
    Messages:
    147
    Location:
    Sudbury, Ontario, Canada
    Truck is a 2005 Volvo tri axle dump truck with a 18 speed eaton.

    Looking for a how to adjust the clutch brake as it isn't working very well. I have searched the www but seem to only find clutch adjustment how tos no clutch brake how tos.

    Also need to check it for wear as the truck is new to the company so unsure how many times it's been adjusted..

    Thanks for any info/ links!!

    Chris
     
  2. Iron Horse

    Iron Horse Senior Member

    Joined:
    Jun 9, 2008
    Messages:
    757
    Location:
    ,
    Clutch brake adjustment is really a bi-product of clutch adjustment . If the clutch itself is in good condition and the free travel etc is correct , the clutch brake should work if it is not worn out . When the yoke pulls back on the throwout bearing , which has a flat face on it , it pinches the clutch brake disc between itself and the flat face on the front of the box . The brake disc being splined to the input shaft stops the shaft to allow a gear to be selected . You can buy a hinged brake disc that can be fitted with the box in situ . Once the old one is air chiseled out , the new one is fed around the shaft and locked together with a pin . People over clutching cause most of the wear . If a clutch is used at all whilst driving , it should only be pushed in about half way , just enough to make the pressure plate let go . Pushing all the way to the floor has the clutch brake trying to slow the main shaft at highway speeds .
     
  3. hollywood

    hollywood Active Member

    Joined:
    May 16, 2009
    Messages:
    30
    Occupation:
    Coporate Technician Trainer
    Location:
    Albuquerque
    Here is a link to an Eaton clutch service manual. You should only have to adjust the clutch and freeplay on your clutch. There is a check for clutch brake squeeze after you get everything adjusted using a .010" feeler gauge between the release bearing and the clutch brake, it should clamp and hold the feeler gauge.

    You did say Volvo so I am assuming it is a hyrdraulic linkage so the freeplay adjument is done at the pedal, not like adjusting linkage and looking for the 1/16" play between the clutch fork fingers and the throwout bearing, on a hydraulic linkage there is no play there.

    What I would advise you to check: on Volvo's with hydraulic linkage a common clutch failure was from lack of lube. The grease fitting to the throwout bearing would get overlooked during a service or if it did get greased the the inspection cover would not get removed to verify grease was coming out of the throwout bearing shaft. It is common for the grease crossover tube to break, come loose or the fitting on the bell housing would come loose and wear out the fitting from vibration and crack the fitting. All of these leading to grease not making it to the throwout bearing shaft.

    http://www.roadranger.com/ecm/idcplg?IdcService=GET_FILE&dID=269304
     
    Last edited: May 31, 2009
  4. Muffler Bearing

    Muffler Bearing Senior Member

    Joined:
    Mar 26, 2009
    Messages:
    274
    Occupation:
    Truck Mechanic
    Location:
    Colorful Colorado
    Wow, volvo runs hydraulic? yikes. First thing I would do is see if there is any clutch brake left with a visual inspection. See if oil is coming out the input shaft on the trans. I know this is avoiding your actual question , but it's the path I would take if a driver mentioned no clutch brake.
    tim
     
  5. Iron Horse

    Iron Horse Senior Member

    Joined:
    Jun 9, 2008
    Messages:
    757
    Location:
    ,
    They are hydraulic over air and the free play is checked at the slave cylinder . If it didn't have free play after the return spring pulls the push rod back in , the throwout bearing would be spinning all the time and would burn out . The clutch itself should be a self adjusting type .
     
  6. Muffler Bearing

    Muffler Bearing Senior Member

    Joined:
    Mar 26, 2009
    Messages:
    274
    Occupation:
    Truck Mechanic
    Location:
    Colorful Colorado
    Sounds complicated, lots of things to leak, I guess something like that will be necessary with the new electronic shifting standards huh?
     
  7. hollywood

    hollywood Active Member

    Joined:
    May 16, 2009
    Messages:
    30
    Occupation:
    Coporate Technician Trainer
    Location:
    Albuquerque
    I have not seen any hydraulic over air. All the trucks we run are just hydraulic and no free play at the throwout, adjustment is made at the pedal so the driver feels what would normally be freeplay.
    You also stated what was one of my questions to bowtie"The clutch itself shoud be a self adjusting type" so Is the clutch self adjuting?
     
  8. Iron Horse

    Iron Horse Senior Member

    Joined:
    Jun 9, 2008
    Messages:
    757
    Location:
    ,
    This is the bit that goes psst psst when you change gears in a Volvo . :D

    Air assist servo .
     

    Attached Files:

  9. Iron Horse

    Iron Horse Senior Member

    Joined:
    Jun 9, 2008
    Messages:
    757
    Location:
    ,

    I'm sorry , i overlooked this question earlier . I was referring to the pressure plate itself when i said it should be a self adjusting type . It depends on what pressure plate the factory used when it was specked with the 18 speed Eaton in lieu of the 14 speed syncro Volvo box . If they used an input shaft on the 18 speed that suited the Volvo clutch pack , then maybe not . But if they used a Spicer pressure plate , then i would think it should be a self adjusting type , i think they are called an "Easy Pedal" . They still need fine adjustment on the push rod to ensure the throwout bearing is not constantly spinning .
     
  10. hollywood

    hollywood Active Member

    Joined:
    May 16, 2009
    Messages:
    30
    Occupation:
    Coporate Technician Trainer
    Location:
    Albuquerque

    Ours looks nothing like that. So the differance is that we are running the 10 speed in our fleet and don't need the air assist, we are also running the solo clutch.
     
  11. Juggernaut

    Juggernaut New Member

    Joined:
    May 11, 2010
    Messages:
    4
    Location:
    On the Road
    96 Volvo Clutch Brake

    I usually don't have a problem maintaining my own rig. I will tell ya folks that I'm not a commercial OTR operator. My rig is a registered motor home, a retired work horse. Been driving it for 4 years.
    Eaton clutch brake has me puzzled. I haven't adjusted the clutch or clutch brake myself, although it doesn't seem to be a big deal when I go for lube service. I've had it adjusted once in 4 years. It is difficult to get into any gear after a stop. I must 'feather' the accelerator pedal a bit which enables me to slip the trans into gear without grinding.
    There is also some sort of metal shaft hanging from the inspection plate which has a nut adjustment on it. I also have the manual but it doesn't show this 'dangle' hanging from the inspection plate.
    Any help would be appreciated.
    Bob
     
  12. Juggernaut

    Juggernaut New Member

    Joined:
    May 11, 2010
    Messages:
    4
    Location:
    On the Road
    I usually don't have a problem maintaining my own rig. I will tell ya folks that I'm not a commercial OTR operator. My rig is a registered motor home, a retired work horse. Been driving it for 4 years.
    Eaton clutch brake has me puzzled. I haven't adjusted the clutch or clutch brake myself, although it doesn't seem to be a big deal when I go for lube service. I've had it adjusted once in 4 years. It is difficult to get into any gear after a stop. I must 'feather' the accelerator pedal a bit which enables me to slip the trans into gear without grinding.
    There is also some sort of metal shaft hanging from the inspection plate which has a nut adjustment on it. I also have the manual but it doesn't show this 'dangle' hanging from the inspection plate.
    Any help would be appreciated.
    Footnote; It's a Super 10
     
  13. mr T

    mr T Member

    Joined:
    Apr 16, 2010
    Messages:
    10
    Location:
    maine
    Dont khow about volvo but on my cat & cummins i always adjusted clutch to maintain !\2 gap between bearing &clutch brake
     
  14. mr T

    mr T Member

    Joined:
    Apr 16, 2010
    Messages:
    10
    Location:
    maine
    That was 1|2 inch gap by the way
     
  15. sgottabeford

    sgottabeford New Member

    Joined:
    Aug 20, 2011
    Messages:
    2
    Location:
    australia
    Dangly thing

    An old thread but if you checkit again I think youll find the dangly thing coming out of the inspection cover is a grease nipple.
     
  16. miro

    miro Active Member

    Joined:
    Aug 9, 2011
    Messages:
    35
    Location:
    Ontario Canada
    Volvo with an Eaton transmission could use either an Eaton clutch or a Meritor clutch. If it as Solo Clutch it is self adjusting and if it is not self adjusting then thae adjuster is probably siezed. If it is a Meritor or Eaton Value Clutch then it has a fork holding the a adjusting ring. If it is an easy pedal there is a 5/8"bolt inside for adjusting. See which one you have for adjusting.
     
  17. Greg

    Greg Senior Member

    Joined:
    Jan 28, 2008
    Messages:
    1,175
    Occupation:
    Excavating Contractor
    Location:
    Wi
    I have Macks, two with Mack 18's and one with a Fuller 10 speed. You can change the clutch brake as described above. There is a way to adjust the clutch brake on mine. Everything is mechanical. To do the clutch brake there is a lever or arm which fits to a shaft which goes into the bell housing. There is an adjustment with a lock nut on the arm which adjusts the clutch brake. If the clutch brake is set up in this method it is than necessary to adjust the pressure plate as the change in the linkage for the clutch brake adjustment will throw the pressure plate out of adjustment.
     
  18. miro

    miro Active Member

    Joined:
    Aug 9, 2011
    Messages:
    35
    Location:
    Ontario Canada
    Sorry, but on a pull type clutch you should never use the outside linkage to adjust for wear, only the internal.
     
  19. Greg

    Greg Senior Member

    Joined:
    Jan 28, 2008
    Messages:
    1,175
    Occupation:
    Excavating Contractor
    Location:
    Wi
    you are correct miro. Once you adjust the clutch brake as described above than you MUST go back and use the internal adjustment for the pressure plate.
     
  20. RobVG

    RobVG Senior Member

    Joined:
    Jun 21, 2009
    Messages:
    969
    Occupation:
    "Fleet Manager" / Mechanic) 13 excavators (1miniKo
    Location:
    Seattle WA
    Did a web search on if I could adjust the clutch brake on a road ranger. Took me right to HEF. Shoulda started here in the first place.

    Good info.
     
    Last edited: Jun 12, 2012