jim Posted June 25, 2005 Share Posted June 25, 2005 Hi I was wondering how far off the floor my clutch should be starting to grab. It grabs high right now, almost to the top of the pedal. The truck is a 1985 u600 mack. Is this normal, or to high ? As a note " it isn't slipping" just curious if there is something I should adress. Thanks in advance for any replies Jim ! Quote Link to comment https://www.bigmacktrucks.com/topic/5-clutch/ Share on other sites More sharing options...
Barry Posted June 25, 2005 Share Posted June 25, 2005 Hi I was wondering how far off the floor my clutch should be starting to grab. It grabs high right now, almost to the top of the pedal. The truck is a 1985 u600 mack. Is this normal, or to high ? As a note " it isn't slipping" just curious if there is something I should adress. Thanks in advance for any replies Jim !Your clutch should grab about half way up from the floor...give or take. This should be true for most heavy trucks. Quote Barry - Watt's Truck Center Parts Manager and BMT Webmaster...1-888-304-MACK Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-15 Share on other sites More sharing options...
jim Posted June 25, 2005 Author Share Posted June 25, 2005 Your clutch should grab about half way up from the floor...give or take. This should be true for most heavy trucks.<{POST_SNAPBACK}>Thanks Barry ! Quote Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-17 Share on other sites More sharing options...
Guest Guest_truxnut_* Posted June 25, 2005 Share Posted June 25, 2005 If you have a Spicer pull type clutch how much free play do you have in the pedal? A inch to 1&1/2 is normal, less and you may need to adjust the clutch.Spicer clutchs are adjusted internaly on the cover. Some late ones are self adjusting and the adjuster mat have quit. Quote Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-19 Share on other sites More sharing options...
jim Posted June 26, 2005 Author Share Posted June 26, 2005 If you have a Spicer pull type clutch how much free play do you have in the pedal? A inch to 1&1/2 is normal, less and you may need to adjust the clutch.Spicer clutchs are adjusted internaly on the cover. Some late ones are self adjusting and the adjuster mat have quit.<{POST_SNAPBACK}>Thanks for your help truxnut! I have about one inch of free play if that. I will have to adjust it. Thanks Jim ! Quote Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-44 Share on other sites More sharing options...
truxnut Posted June 29, 2005 Share Posted June 29, 2005 Jim : Be sure you adjust the clutch presure plate it's self and not the linkage. Once the presure plate is right then and only then adjust the linkage. Quote John Evans, Trucks & Dogs are expensive!! Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-96 Share on other sites More sharing options...
Freightrain Posted June 29, 2005 Share Posted June 29, 2005 This has always been a wonder of mine. I have looked thru the old owners manual about clutch adjustment but not wanted to touch it. Mine is kinda close to the top, but also does not slip. Guess it is okay for the mean time. Don't want to screw it up.. I don't know how many million miles are on it...but it works so I don't want to mess it up. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-105 Share on other sites More sharing options...
b61pickup Posted June 29, 2005 Share Posted June 29, 2005 To adjust the clutch you adjust the pressure plate internally to get between 1\2 and 9\16 between the throwout bearing and clutch brake, then adjust the linkage to get 1\8 between the fingers and the bearing.after this is done measure the free play( whatever it is,is right at this time) and when you loose 1\2 of whatever you have it is time to adjust again. This is from the spicer book. Quote Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-110 Share on other sites More sharing options...
Freightrain Posted June 29, 2005 Share Posted June 29, 2005 On normal car/trucks you adjust the throw out arm for clearance. Here you adjust the plate for clearance from the throw out. Hmmm, okay. That is the reason I have not dug into it. I have read people that have got it screwed up somehow and don't have pedal anymore . Don't want to get into that.Some day when I have nothing better to do....maybe I'll swing under it and start poking around. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-111 Share on other sites More sharing options...
truxnut Posted June 30, 2005 Share Posted June 30, 2005 Larry: With your B model with Mack engine & trans you most likely have a Mack PUSH style clutch which adjusts like a regular car clutch. Only the pull type clutchs do you rotate a ring in the presure plate. Quote John Evans, Trucks & Dogs are expensive!! Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-117 Share on other sites More sharing options...
Packer Posted July 10, 2005 Share Posted July 10, 2005 On normal car/trucks you adjust the throw out arm for clearance. Here you adjust the plate for clearance from the throw out. Hmmm, okay. That is the reason I have not dug into it. I have read people that have got it screwed up somehow and don't have pedal anymore . Don't want to get into that.Some day when I have nothing better to do....maybe I'll swing under it and start poking around.←Back in the GOD (Good Old Days), a 1/2 in socket extention made a great gage for that 1/2 in adjustment.Packer Quote Keep a clutchin' Link to comment https://www.bigmacktrucks.com/topic/5-clutch/#findComment-242 Share on other sites More sharing options...
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