Jump to content

  •  

  • Welcome to BigMackTrucks.com

    Welcome to BigMackTrucks.com, the best resource on the Internet for Antique, Classic and Modern Mack Trucks!  

     

    Please login or register to take advantage of everything BMT has to offer.  Memberships are Free and offer many benefits:

     

    • Start new topics and reply to others
    • Subscribe to topics and forums to get automatic updates
    • Showcase your trucks in our Garage
    • Photo Gallery, Member Blogs and much more...
    • Add events to our community calendar
    • Create your own profile and make new friends
    • Customize your experience!
    • Mack Dealer and Corporate personnel can contact the ADMIN after registration for access to the Dealer Forums.

    If you are having trouble logging in or haven't received your validation email, you can post as a guest in the Guest Forum.


    login  register
    Guest Message by DevFuse
     

    Photo

    99 Ch613 Clutch Adjustment



    • Please log in to reply
    12 replies to this topic

    #1 OFFLINE   king cotton

    king cotton

      Over Drive

    • Puppy Poster
    • PipPipPipPipPip
    • 28 posts
    • Make:mack
    • Model:ch 613
    • Year:99

    Posted 26 August 2010 - 09:29 PM

    need to adjust clutch. it engages all the way at the top and have no free play. how hard is it to do? any special tools?? never done this before. i got a older guy that drives one of my trucks (hauling grain out of field) and says he can do it in 30 mins, but i dont trust him and looking for some tips or advice.
    thanks.

    #2 OFFLINE   rhasler

    rhasler

      Wotta revoltin' development

    • Moderator
    • PipPipPipPipPipPipPipPipPipPip
    • 1,876 posts
    Contributor

    Posted 26 August 2010 - 09:45 PM

    need to adjust clutch. it engages all the way at the top and have no free play. how hard is it to do? any special tools?? never done this before. i got a older guy that drives one of my trucks (hauling grain out of field) and says he can do it in 30 mins, but i dont trust him and looking for some tips or advice.
    thanks.

    If everything goes right he's probably not too far off on the time it will take. Roll the engine around until the adjuster is visible through the hole in the bell housing. Depending on the clutch you will need to remove the lock tab or depress the spring on the adjuster. Push and hold the clutch pedal all the way in. Depending on the clutch: For a clutch with lock tab you will need a long screwdriver or prybar (or preferably a clutch adjusting tool) to turn the ring that the lock ring engages against. For a clutch with spring lock you will need a 5/8" end wrench and a screwdriver or prybar to depress the adjuster while turning. Turn the adjuster clockwise to increase free travel and counterclockwise to decrease free travel. You are looking for approx. 1/2" gap between the bearing and the clutch brake, or about 1 1/2" at the pedal. You should feel clutch brake "squeeze" at about 1/2" from the floor. You may also have to adjust the external linkage inorder to get the right clutch brake squeeze. It is important to make the adjustment internally, using the adjuster, in order to get the correct bearing travel. Simply adjusting using the external linkage adjustment will only create slack in the linkage, which will feel like free play, but will not change the clutch engagement/disengagement point.
    If you have problems with making the adjustments you may want to check out the Roadranger website.
    "Mebbe I'm too ugly and stupid to give up!"

    #3 OFFLINE   fjh

    fjh

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 1,303 posts
    • Location:bc canada

    Posted 26 August 2010 - 10:18 PM

    If everything goes right he's probably not too far off on the time it will take. Roll the engine around until the adjuster is visible through the hole in the bell housing. Depending on the clutch you will need to remove the lock tab or depress the spring on the adjuster. Push and hold the clutch pedal all the way in. Depending on the clutch: For a clutch with lock tab you will need a long screwdriver or prybar (or preferably a clutch adjusting tool) to turn the ring that the lock ring engages against. For a clutch with spring lock you will need a 5/8" end wrench and a screwdriver or prybar to depress the adjuster while turning. Turn the adjuster clockwise to increase free travel and counterclockwise to decrease free travel. You are looking for approx. 1/2" gap between the bearing and the clutch brake, or about 1 1/2" at the pedal. You should feel clutch brake "squeeze" at about 1/2" from the floor. You may also have to adjust the external linkage inorder to get the right clutch brake squeeze. It is important to make the adjustment internally, using the adjuster, in order to get the correct bearing travel. Simply adjusting using the external linkage adjustment will only create slack in the linkage, which will feel like free play, but will not change the clutch engagement/disengagement point.
    If you have problems with making the adjustments you may want to check out the Roadranger website.

    Just a Note !Check the clutch brake squeaze first if its not right correct it with the out side adjustment!Then proceed with the half inch bearing clearance/1 1/2 free play!This way you do the job once !

    #4 OFFLINE   HK Trucking

    HK Trucking

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 1,557 posts
    • Location:Appleton WI

    Posted 28 August 2010 - 06:52 AM

    Just a Note !Check the clutch brake squeaze first if its not right correct it with the out side adjustment!Then proceed with the half inch bearing clearance/1 1/2 free play!This way you do the job once !


    I hope he doesn't encounter a jammed adjusting ring with the old "lockstrap" type adjuster!!!!!!

    Time to get out the air chisel with a long blunt bit, or long steel drift & 5 lb. hammer!
    "If You Can't Shift It Smoothly, You Shouldn't Be Driving It"

    #5 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 18 December 2012 - 07:12 PM

    If everything goes right he's probably not too far off on the time it will take. Roll the engine around until the adjuster is visible through the hole in the bell housing. Depending on the clutch you will need to remove the lock tab or depress the spring on the adjuster. Push and hold the clutch pedal all the way in. Depending on the clutch: For a clutch with lock tab you will need a long screwdriver or prybar (or preferably a clutch adjusting tool) to turn the ring that the lock ring engages against. For a clutch with spring lock you will need a 5/8" end wrench and a screwdriver or prybar to depress the adjuster while turning. Turn the adjuster clockwise to increase free travel and counterclockwise to decrease free travel. You are looking for approx. 1/2" gap between the bearing and the clutch brake, or about 1 1/2" at the pedal. You should feel clutch brake "squeeze" at about 1/2" from the floor. You may also have to adjust the external linkage inorder to get the right clutch brake squeeze. It is important to make the adjustment internally, using the adjuster, in order to get the correct bearing travel. Simply adjusting using the external linkage adjustment will only create slack in the linkage, which will feel like free play, but will not change the clutch engagement/disengagement point.
    If you have problems with making the adjustments you may want to check out the Roadranger website.


    Talk about resurrecting an old thread! But, when I typed "mack clutch adjustment" into google, the link to this thread was the 3rd hit...and since I trust y'all ta give good advice (well, moreso than sites like ehow.com, anyways... :tease: ), I figure I'd go ahead & post here.

    Clutch brake quit working today. It ain't the first time that's happened, though...usually tosses 'em off every 6-8 months, and I USUALLY carry one in the truck with me, but hadn't bought a replacement since the last time I had to put one on. Anyway, I picked up a new one on my way to my last drop to install when I got home...but the old one was still there! 2-piece bolt together style, and the tangs (ends of the bolts?) had sheared off so it wasn't really doing much to stop the input shaft from spinning. I'd normally buy the ones that go together with the 2 rods that you stick into the brake, place the brake around the shaft, and then squeeze the rods together...then remove the rods. Seems to be easier than the bolt-together ones (this one was apparently installed when they did the clutch, because I didn't put it on there....) Anyway, the new clutch brake was the only one NAPA had...and it's the kind with the press-in roll pin. Which leads me to my series of questions (since I've never put this kind on before).

    The bag the thing came in says there's supposed to be 1/2" between the brake and the release bearing housing...so if the brake weren't in there, that would be roughly 7/8" gap (3/8" wrench fits over the brake....plus the 1/2" gap) with no brake in place. Right now, I can take a bolt with a 15/16" head on it and spin it around in the gap....so that's quite a bit more gap than it sounds like should be there....so I'm thinking it needs adjustment.

    Am I on the right track so far?

    The other factor leading me to believe it needs to be adjusted is that when the clutch was first done, the friction zone was MUCH closer to the floor. Now, nothing happens until the pedal is almost fully released.

    While I was under there removing the old clutch brake, I noticed something I've never seen before....I guess in all these years, either it has never ended up stopped down there by the inspection plate when I was under there greasing, installing a clutch brake, etc....or else I just never noticed it before.... (see attached pic)...I'm guessing that this clutch is the spring-lock type...because the yellow plastic around the bolt says to depress the bolt. There's also casting in the clutch housing that says "ADJ FOR WEAR"...so I'm pretty sure that's where I'd make the adjustment.

    So how far do I turn the bolt and how will I know when it is properly adjusted? :idunno: Am I looking for that 7/8" gap (no brake installed yet) as I'm adjusting? Do I have to keep climbing up into the truck and stepping on the clutch to see where it is engaging? I've got a 2x4 cut to length to hold the clutch pedal in when I'm greasing it so I can access the throwout bearing's fitting...holds the pedal about 1/2 from the floor....is that about where the pedal should be while I'm adjusting?

    So many questions....hoping I don't screw it up. If it isn't already obvious, it'll be my first time adjusting a clutch. :pat:

    Attached Files


    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

    #6 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 18 December 2012 - 08:21 PM

    ...well, between this and this...I think I'll get it figured out. I printed out pages 22-25 of the second link about setting up the clutch...and it seems as though that would get me adjusted up proper.
    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

    #7 OFFLINE   MACKS

    MACKS

      BMT Forum Guru

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPip
    • 803 posts
    • Location:Long Island NY
    • Make:mack
    • Model:CL-713
    • Year:1996

    Posted 18 December 2012 - 08:26 PM

    I adjust mine till I get about 2" free pedal and my clutch brake comes into proper adjustment at the same time,on a side note why are you going through so many clutch brakes,one mistake is applying the brake or fully depressing the clutch pedal while the truck is moving,good luck and be very careful if you mess with the outside adjustment,you can get screwed up real quick if you do it wrong,don"t ask me how I know,lol

    #8 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 18 December 2012 - 10:08 PM

    This stupid sunovabitch just ain't going on. I can get it wrapped around the input shaft, but it won't click shut so that I can press the pin into place. I've tried running an old dog collar up over the top to pull down while I push up on the bottom half....I've tried using a screw driver to pry the two sides apart while I try to pinch it together....I've tried reaching in there with channel locks to squeeze the damn thing together....nothing seems to be working. I can pull the clutch brake out and it opens and closes just fine....but once I get it up in there, it just won't close. The tangs are in the grooves...it won't spin on the shaft...and there's a little play in it, but that's because it isn't clamped all of the way shut. The brakes I usually use have a pair of rods you insert into some holes to assist with closing the damn thing...provide some leverage to get it locked into place....but not this one. I'm thinking it's worse than the one time I tried using the bolt-together type. It isn't SUPPOSED to be difficult....can usually put one on in less than 5 minutes....but this was the only style they had there at NAPA.

    Anyway, it's starting to piss me off....almost to the point where I'm tempted to run tomorrow without it and try to find the style I prefer to use along the way....but money is tight right now and I've already bought this one, so I'd like to be able to use the damn thing.
    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

    #9 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 18 December 2012 - 10:20 PM

    ...and up until this truck, I've never had a problem with clutch brakes. Even when I drove the same truck for a year or two every day, never had a problem with them wearing out and certainly never had one break or fall apart on me...but on this truck, this is the 4th one I'm putting on.
    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

    #10 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 19 December 2012 - 01:00 AM

    Well, I got'er did. The clutch adjustment is pretty easy...getting that stupid clutch brake on, on the other hand, was a completely different story. Won't be buying this style again...even after I got it clipped on there, it didn't want to press the pin into place properly...but I eventually got it. Funny thing was, though, when I got it to where I only had 1/2" between the clutch brake and the release bearing housing so that it would press the pin into place, there was over 4" of free travel in the clutch pedal. It still worked...but I wouldn't be happy with that. So, I backed off the adjustment again so I only had 2" of free travel. Put the friction zone of the clutch right where I wanted it, the clutch brake works, and I'm happy. Time to wind down a bit, get my paperwork done, get a shower, and HOPEFULLY get to bed sometime before my alarm starts going off....


    ....been asking myself why I bought a truck an awful lot this past week or two. Hopefully I'll get everything fixed up before too long and it'll give me another good stretch of time without any problems.

    Oh well....'nother project done.
    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

    #11 OFFLINE   turckster

    turckster

      BMT Veteran VIP

    • Big Dog
    • PipPipPipPipPipPipPipPip
    • 132 posts
    • Location:Lubbock, TX

    Posted 19 December 2012 - 07:15 AM

    Replacing clutch brakes can be a chore, I feel your pain. On clutch adjustments, the 1/2" clearance between the clutch brake and t/o bearing is the most important adjustment. After that the clutch brake crush should be set. There should be approx 1/2" gap between floor/stop and pedal when t/o bearing contacts clutch brake. Once these 2 settings are adjusted the free travel should be 1 1/2-2".

    #12 OFFLINE   theakerstwo

    theakerstwo

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,172 posts
    • Location:mounds okla
    • Make:mack
    • Model:b61
    • Year:1957

    Posted 19 December 2012 - 02:53 PM

    ...and up until this truck, I've never had a problem with clutch brakes. Even when I drove the same truck for a year or two every day, never had a problem with them wearing out and certainly never had one break or fall apart on me...but on this truck, this is the 4th one I'm putting on.

    When a cluth brake goes bad it will be a clutch not relaeseing proper due to wrong adjustment or the center plate is draging and most common is drivers using the clutch brake to slow the truck down not know that it will slow the truck down when pushed too for down when in gear and moving.I have seen it many times and it is in most case the driver hold the clutch down when moving. I work with a man that goes thru two or three brakes in a year. He is aware of his problem but claims he cant help it cause its just the way he drives.If the pressure plate is set properly then the clutch disc are free to rotate by the time the brake is begining to be crushed.Now if it is out of gear then that will stop the disc and input shaft from turning but if it is in gear the wheels and weight of the truck will keep the imput shaft turning even if its a new truck.
    glenn akers

    #13 OFFLINE   RowdyRebel

    RowdyRebel

      BMT Certified Know-It-All!

    • Pedigreed Bulldog
    • PipPipPipPipPipPipPipPipPipPip
    • 2,502 posts
    • Location:SoIL
    • Make:Mack
    • Model:CH613
    • Year:2001

    Posted 19 December 2012 - 03:57 PM

    Only time my clutch pedal is pushed to the floor is when I'm stopped. I usually try to grab whatever gear I'm going to start off in as I'm coming up to the stop, and step on the clutch just as the rpm's are being pulled down below idle and try to time it so that the clutch pedal hits the floor as the truck comes to a complete stop. Then when it's time to go, I ease the clutch out and my foot won't touch that pedal again until the next time I'm coming to a stop.
    When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!




    0 user(s) are reading this topic

    0 members, 0 guests, 0 anonymous users