1979 Dump Truck Clutch Parts

[Gunny65]

I have a 1979 DM685sx T/A Dump Truck.  The clutch is worn to the point it can no longer be adjusted and it is slipping. I believe I have the MaxiTorque Transmission (TRL107) with MACK clutch. The ID plate says: (REGU.S. MACK Maxitorque Transmission PAT.OFF) There are no other numbers or markings on the plate (top left side rear of trans housing).

Where should I go to buy clutch parts for this year and model?  

I found a service manual that will help me remove and install the clutch. Any pointers would help as well.

Thanks!

[Joey Mack]

terry???  you ever break one of the 'dogs' off the pressure plate when trying to adjust a clutch that has been hammered to death, and your trying to get every bit out of it, but it's stuck,  jammed up with clutch dust in the teeth on the adjuster ring???  I have..  That sucks...  

[mechohaulic]

43 minutes ago, JoeH said:

IIRC on this style clutch you take out the lock tab, push the clutch pedal in, then spin the flywheel to thread the clutch tighter? Then reinstall the lock tab and you're good to go...

I may be a weee bit off though...

fly wheel stays stationary the large screw driver/ bar or proper clutch tool (as Joey mentioned)  is used to turn the adjusting ring which the Y lock held securely. modern day pressure plates have a spring loaded  5/8 hex which takes the place of Y lock. it a challenge when the Y lock which at times needs a little persuasion to be remove falls in to the bell housing . had road call where the Y lock fell out /lost. took a lot of road side adjusting to get unit back running. 

 

[mechohaulic]

when someone doesn't know the pedal has to be depressed to adjust and think it's frozen then takes an air hammer to move ring (NOT ME) the tabs will/do break off. have delt with stuck/ gummed up adjuster not moving. have taken out the Y lock sprayed the sh-t out of pressure plate/ ring  THEN stared the unit. some times it worked. didn't work do a quick  dump clutch peddle rapidly. shock at times got things moving.

[mechohaulic]

Just now, mechohaulic said:

when someone doesn't know the pedal has to be depressed to adjust and think it's frozen then takes an air hammer to move ring (NOT ME) the tabs will/do break off. have delt with stuck/ gummed up adjuster not moving. have taken out the Y lock sprayed the sh-t out of pressure plate/ ring  THEN stared the unit. some times it worked. didn't work do a quick  dump clutch peddle rapidly. shock at times got things moving.

started the unit NOT stared the unit.

[mechohaulic]

On 12/4/2023 at 5:55 PM, terry said:

Don’t know what kind of clearance you have there, but sometimes you can just slide trans. Back and do your clutch work.   Terry

almost looks like there is  still rail road mechanism under front  combined with the dump turn table rig  ; clearance might be less then minimum to put a drop light under to see the transmission never mind remove it. just sayin

[terry]

43 minutes ago, Joey Mack said:

terry???  you ever break one of the 'dogs' off the pressure plate when trying to adjust a clutch that has been hammered to death, and your trying to get every bit out of it, but it's stuck,  jammed up with clutch dust in the teeth on the adjuster ring???  I have..  That sucks...  

can,t say that I have, I was a Mack dump owner, driver for 40 plus years, so most of my work was on my own truck. I would help in the shop for the company that I worked for once in a while , seems like his mechanic would use a rattle gun with a long bit to knock a stuck one loose.  Terry  

Edited December 6, 2023 by terry

[terry]

47 minutes ago, terry said:

This is a new one on me to adjust.    terry

I was always told if you started it without the lock in it would loosen the clutch 🤷‍♀️

[Joey Mack]

yes terry it does,,,  right away.....

[Gunny65]

It took me a while but I got the new clutch in. I put in the Eaton 9 spring ''Easy Pedal''  clutch. Yes, I went ahead and paid a local guy to put it in.  He was backed up so it took a while but I now have a new clutch.  Thanks for all the suggestions. Now I need to get some other things working.  It is fully usable at this point but there a lot of little things that need attention. I will make new posts for those questions. Again, thanks everyone.