markseven 29 #1 Posted October 19 Just tried putting a 5/8 ×84 inch long drive belt on the Bronco 14 Automatic. Found out the flat idler pulley was frozen up so im trying to find a new one. I have the new belt on and it seems awfully tight I'm not sure it's the correct length ? I mean its so tight I can not get the handle to engage all the way. Thoughts prayers anyone. Share this post Link to post Share on other sites
ri702bill 10,084 #2 Posted October 19 Is the flat idler the proper diameter for the application?? They are not all the same... Share this post Link to post Share on other sites
markseven 29 #3 Posted October 19 It should be looks original. Just like the drive belt original but looks very wore out probably only a 1/2 inch wide and stretched over the 55 years. Share this post Link to post Share on other sites
Ed Kennell 43,119 #4 Posted October 19 Got a picture of the belt / idler pulley assembly? 1 Share this post Link to post Share on other sites
markseven 29 #5 Posted October 19 Not right now its over at my son's place. Share this post Link to post Share on other sites
markseven 29 #6 Posted October 19 I would like to get the new pulley ordered up from wheelhorse parts and more but uncertain which one to purchase. Share this post Link to post Share on other sites
Ed Kennell 43,119 #7 Posted October 19 Any help here Garry? @gwest_ca Share this post Link to post Share on other sites
Moparfanforever 892 #9 Posted October 19 Drive belt is Toro 7478 , 5/8x84 Idler pulley is 112426 or these alternatives . Very common pulley, do a search on those numbers and you will find cheaper prices. Share this post Link to post Share on other sites
Lee1977 7,394 #10 Posted October 19 As said above 112426 the diameter is 3 3/16" to the out side of the flange. Share this post Link to post Share on other sites
markseven 29 #11 Posted October 25 On 10/19/2025 at 2:05 PM, Moparfanforever said: Drive belt is Toro 7478 , 5/8x84 Idler pulley is 112426 or these alternatives . Very common pulley, do a search on those numbers and you will find cheaper prices. Drive belt is 5/8 ×86 inches Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,752 #12 Posted October 25 Original drive belt 7478 is 5/8" x 84.22" You will not find a fractional length belt from standard suppliers. You may have to go to 85" length. Share this post Link to post Share on other sites
markseven 29 #13 Posted October 25 Tried the 84 then a 85 still way to short 86 fit perfect Share this post Link to post Share on other sites
markseven 29 #14 Posted October 25 Very confused but everything is standard pulleys etc . Measured the wore out belt 86 inches long Share this post Link to post Share on other sites
kpinnc 15,725 #15 Posted October 27 On 10/25/2025 at 5:58 PM, markseven said: Measured the wore out belt 86 inches long As I understand belt measurements- "A" belts are numbered at 2 inches shorter than the outside measurements and "B" belts are 3 inches shorter than the outside measurements. So a pulley system measuring 86 inches requires an A84 belt. The same situation with B pulleys would yield a B83. It was explained to me that this is because the belt is actually measured in the center not inside or outside. Clear as mud... I have zero documentation to back this up, but in practice the rule has served me well many times, as nearly everything I have is custom on varying levels. I got this info from a NAPA parts store manager years ago. Anyone who wants to correct me feel free to jump in. Share this post Link to post Share on other sites
