mrc 841 #1 Posted December 3 hello men, for over 30 years i have plowed with an eight speed. i recently picked up a workhorse 1848. the previous owner installed a kohler 10hp magnum engine. he told me the original twin cylinder engine blew up. the engine drive pulley is only 4 inch. so i installed a 5 inch pulley.. i believe that is necessary to spin the hydro fast enough. correct? i removed a dayton belt BP76. which i believe is a 5/8x79 inch belt. obviously because of the larger pulley i need a longer belt. what size? thank you in advance regards mike Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,102 #2 Posted December 3 Going from a 4" pulley to a 5" requires 2 " more belt so 5/8" x 81". The original belt with the twin cylinder engine was 5/8" x 83". A C-125 with same Eaton transmission used a 5/8" x 81.5" belt. I do not know the correct pulley diameter. Share this post Link to post Share on other sites
ri702bill 8,513 #3 Posted December 3 Mike - too many non OE variables. With a pair of extra hands, try threading a length of rope over the pulleys to get an approximate belt length. Buy 3 returnable belts - the rope length size, one an inch shorter, one an inch longer. Tractor Supply will accept returns if unused and in original sleeve, with the receipt. Been there, done that. 1 1 Share this post Link to post Share on other sites
kpinnc 12,573 #4 Posted December 3 1 hour ago, mrc said: so i installed a 5 inch pulley.. i believe that is necessary to spin the hydro fast enough. correct? 5.25 but yes the hydro spins a little faster. Share this post Link to post Share on other sites
mrc 841 #5 Posted December 3 before installing the pulley i measured it. you are correct kpinnc it was 5.25 inches in diameter. i guess my first question is, is that the proper size pulley when running an eaton 1100 tranny? thank you mike Share this post Link to post Share on other sites
953 nut 55,870 #6 Posted December 3 (edited) 3 hours ago, mrc said: is that the proper size pulley when running an eaton 1100 tranny? Yes it is the proper size pulley and a 5/8 by 82" belt should do the job. The circumference of the 4" pulley is about 12.6" and the 5 1/4" pulley has a 16.5" circumference, so the portion of the pulley being contacted by the belt increases by about two inches. Edited December 4 by 953 nut Share this post Link to post Share on other sites
kpinnc 12,573 #7 Posted December 4 4 hours ago, mrc said: i guess my first question is, is that the proper size pulley when running an eaton 1100 tranny? Yes sir it is. Same for the Sundstrand hydro as well. Share this post Link to post Share on other sites
mrc 841 #8 Posted December 5 just wanted to update. i originally tried a 7473 wh belt that i had in my garage. . google says the 7473 wh belt is 5/8 x 82 inches. still a bit too loose for my liking. i installed a dayton BP78 belt. which is 5/8 x 81 inches. fit very well. i had to top off the tranny and used 10W-30 motor oil. the fluid on the dipstick looked like a cross between motor oil and atf. very slightly red but, thick like motor oil. we are getting snow right now. so my plan was to try it out after the storm and then drain and refill with motor oil and fresh filter. i was thinking about synthetic 10W-30 as well. any thoughts on that are appreciated. the help i get from this site is much appreciated! THANK YOU MEN! regards mike 1 Share this post Link to post Share on other sites
Brockport Bill 1,718 #9 Posted December 5 2 hours ago, mrc said: just wanted to update. i originally tried a 7473 wh belt that i had in my garage. . google says the 7473 wh belt is 5/8 x 82 inches. still a bit too loose for my liking. i installed a dayton BP78 belt. which is 5/8 x 81 inches. fit very well. i had to top off the tranny and used 10W-30 motor oil. the fluid on the dipstick looked like a cross between motor oil and atf. very slightly red but, thick like motor oil. we are getting snow right now. so my plan was to try it out after the storm and then drain and refill with motor oil and fresh filter. i was thinking about synthetic 10W-30 as well. any thoughts on that are appreciated. the help i get from this site is much appreciated! THANK YOU MEN! regards mike Mike: heres a web site i use for belt length - - suggest R Sq members add it to their bookmarks or favorites for future reference .............. https://outdoorpowerinfo.com/belts/wheel_horse_belts.asp?fbclid=IwAR30E10elLLRa8PlrLjmGTcqSvqLUTNkx01uBu4Kp-fUgu5zy0AW0xHBZOM Share this post Link to post Share on other sites
953 nut 55,870 #10 Posted December 5 Here is a link to the Wheel Horse drive belts chart from our files on Red Square. You can sort by model or belt part number and it gives standard size cross reference to standard belt sizes. Share this post Link to post Share on other sites
