Fan Belts

[mackdumper]

hi all,

its that time of year where the burden on your climate control/electrical accessories is at its most, other then winter, when most all accessories are on in high position/maximum use.

well it happened this morning out on I-80 mounthope/rockaway, was running millings from bottom to top of hill about 20 miles.it was one of those stay right and maintain speed hills. i was high gear and revs were dropping so i had to down shift and thats when all hell broke loose1/4 mile from my exit. i had a new altenator and belts installed at start of season/spring oh yeah 96 r-model tandem dump, noticeing then that the belts seemed odd somewhat, the pair werent same in tightnest . i have 2 all together. looks like it could be 3 but no. 1 for alt,waterpump and crank pulleys, and the 1 inner belt is fer the a/c,waterpump, crank and a/c compressor. me thinks i,m going out now to investigate.yup like i said now i thought there was a third belt ,what it was is the inner belt outa the 2 belts total looks like it supposed to go to the a/c compreesor only other way could be a third belt from water pump pulley to a/c comp pulley......uh-uh i don't think that would be a viable(work fer long).anyway i sat on the interstate fer 2 hours waiting fer da boss two get dressed and bring me out the one basic pair of belts so i could get my load off and return home to the barn. now all my life i learned from day one that when replaceing belts its not a bad idea to hold on to the old belts no matter what there condition maybe, either keepem with the vehicle or at the least hangem on the wall in the shop well boss did neither so there i was not to far from my area mack dealer but it being 2:30 am didn't help at all. so wake up boss man and tell me what you did with the old belts and or wheres the new set of belts fer my truck, i mean he has 5 mack tandem dumps of various year and such. how many different types and kinds of belts could there be fer mack trucks. well boss has been in buisness family excavating&trucking fer over 50 years and he just sold the original barn/shop where he operated out of for that amount of time wow what an endeavor,what to keep and what to throw away well anyway our luck was two sets of mack belts vintage late 50's early 60's and boy o boy they fit like a glove anyway good fer me i got home safe along with the truck both of us no worse fer the wear. but!!!!!! i still need that belt so as to run the a/c compressor, now all this story telling has me leading up to this.......squeeling belts ,cause and effect........such as proper adjustment, how tight is to tight, polished/glazed pulleys fiz/clean or replace? procedure install new belts let run fer a couple a days re adjust ? any suggestions/advice... thanx fer hearing me out the/dogg

[Lmackattack]

I just replaed my belts (2). I always tighten by feel. I use a pry bar to pull the alt back and have someone tighten the bolt. I figure a 1/4 inch movement is ok any more and they may slip at high RPM. I dont have a AC unit (yet) so the 3rd belt is not used on my Western. I also installed a fan clutch with the new belts and that greatly improved noise at high RPM as the fan will not work unless its needed

[Too_Krazy]

This link should give you a little info. Generally 1/4" to 1/2" belt deflection at the middle of the longest span with thumb pressure.

http://www.gates.com/file_display_common.c...33%2D0829%2Epdf