GrumpyOldBastige 1 #1 Posted August 1, 2014 Was cutting the grass with my 312-8 this morning. All went well until I noticed a slight burning smell; since it's happened darn near every time out, I knew it was the PTO belt to the deck. Disengaged it- thankfully, the job was done just as the smell became obvious- shut it down, and noticed the shield on the PTO belt tensioner disappeared. This meant nothing was holding the pulleys in place, so they had a little play; thank God I had that belt cinched down tight. Walked my yard to find it, it was in the backyard, in an area where I made my initial passes. The mower must have run it over and hit it, as it was punched into the ground, and one of the blades nicked it. The part is still sound, just a little less pretty. The nut that retains the shield- totally lost, nowhere in sight, the WH must have punched it all the way into the ground. Always something lol... The question: What is the thread pattern on the nut? It takes a 1 1/8" wrench. Need to replace before I use it again. Belt-to-face combat does not sound pleasurable. Is this a hardware store find, or a small engine shop find? Share this post Link to post Share on other sites
dcrage 621 #2 Posted August 1, 2014 Heh Grumpy I ain't the expert on any of this, BUT there may be a spacer on the threaded rod between your shield and the outer pulley -- My 37" SD and 42" SD have them -- Make sure yours is there -- Look for the owners or parts manual for your deck -- It will have the "mule drive" parts listed along with the thread and nut size -- I am a little surprised at the 1 1/8 inch -- My 42" SD uses a 3/4" or so the manual I have says Also, I don't see how the lack of this cover is going to have anything to do with "belt burning" Share this post Link to post Share on other sites
GrumpyOldBastige 1 #3 Posted August 1, 2014 The only guess on burning I have is the belt was slipping and wobbling on the engine side because the tensioner pulleys were moving around on that shaft. The nut on the shield was holding everything in position as far as tensioner pulleys/belt. Everything looked fine on the deck. Definitely a faint burnt rubber smell unless I'm mistaken, which is entirely possible. Will have to look into it. Now that you mention, there was a spacer, probably also buried by the tractor. Two parts to get, now. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,539 #4 Posted August 1, 2014 A 3/4" threaded shaft takes a 3/4" nut and most wrench sizes are 50% larger than the shaft. 3/4" = 6/8" + 3/8" = 9/8" = 1-1/8" wrench. Garry From my notes Outer spacer between cover and pulley # 101757 is 1/2" long Inner spacer between pulleys # 101734 is 5/8" long 1 Share this post Link to post Share on other sites
dcrage 621 #5 Posted August 1, 2014 (edited) A 3/4" threaded shaft takes a 3/4" nut and most wrench sizes are 50% larger than the shaft. 3/4" = 6/8" + 3/8" = 9/8" = 1-1/8" wrench. Gary Thanks for the tutorial on nut and wrench sizes -- Never had this explained to me before Edited August 1, 2014 by dcrage Share this post Link to post Share on other sites
