KCJones 2 #1 Posted May 1, 2021 42”Mower deck belt slipping when mowing. It’s approx 1988 312-8 machine.Not sure if it’s because of Kevlar belt, or belt misalignment, though this doesn’t look to be a problem. Anyone have a suggestion how I can solve this problem? Thanks in advance. Share this post Link to post Share on other sites
Jeff-C175 7,199 #2 Posted May 1, 2021 (edited) How's the idler tension sprng? With the belt removed do the spindles and idler turn smoothly with little effort? With the idler spring removed does the idler support bar move in it's slots properly? @KCJones Edited May 1, 2021 by Jeff-C175 1 Share this post Link to post Share on other sites
JC 1965 1,530 #3 Posted May 1, 2021 Adjust the nut at the end of the PTO rod that runs from the PTO lever to the PTO pulley. That will put more tension on the belt and keep it from slipping. I think you will want to turn it out a couple of turns. Hope that solves the problem. Share this post Link to post Share on other sites
peter lena 8,587 #4 Posted May 1, 2021 agree wit jeff on on possible tension spring issue , or related slide areas , worn out and need replacing . local h/w store probably has the nylon shim pieces you need in the small pull out drawer section . basic deck service , pete 1 Share this post Link to post Share on other sites
Jeff-C175 7,199 #5 Posted May 1, 2021 52 minutes ago, KCJones said: deck belt slipping Let's clarify which belt is slipping. I took your post to mean the belt ON the deck, between the spindles and idler. JC pointed out that you may be referring to the DECK DRIVE BELT. So, exactly which belt are you referring to? Share this post Link to post Share on other sites
Jeff-C175 7,199 #6 Posted May 1, 2021 8 minutes ago, JC 1965 said: Adjust the nut at the end of the PTO rod that runs from the PTO lever to the PTO pulley. That will put more tension on the belt and keep it from slipping. I think you will want to turn it out a couple of turns. Hope that solves the problem. I think you're talking about the PTO clutch adjustment? That wouldn't tension the belt but it could be the clutch slipping so it's possible that is the cause. Tension on the deck drive belt is adjusted with the knob on the mule drive and that may need tightening also. Share this post Link to post Share on other sites
KCJones 2 #7 Posted May 3, 2021 Thanks for all the input. Sorry about not being clearer. But it is pto belt. I have tried both pulleys on pto, I have cranked the tensioner as tight as possible without putting a tool on it. I did put new belt on, hoping to solve the problem, and it was Kevlar belt, and still starts slipping in not so tall grass. Deck is going to get new spindles and bearings soon, but because noise nothing else. Haven’t noticed any significant belt misalignment issues. Share this post Link to post Share on other sites
KCJones 2 #8 Posted May 3, 2021 After reading all the posts, I guess the rod to the pto suggestion is the next thing to try. And confirm it’s not the belt deck slipping, though I don’t think so because belt dressing on drive belt helps but not a fix. Thank you all. Obviously a lot of knowledge here. Thanks again, and I’ll be sure to let you all know how I make out 1 Share this post Link to post Share on other sites
KCJones 2 #9 Posted May 16, 2021 Tightening the rod to the pto solved the problem. Don’t know how I overlooked this. I assumed it was the belt slipping, while all along it was pto. Thanks all!! 1 Share this post Link to post Share on other sites
Jeff-C175 7,199 #10 Posted May 17, 2021 6 hours ago, KCJones said: Tightening the rod to the pto solved the problem. Don’t know how I overlooked this. I assumed it was the belt slipping, while all along it was pto. Thanks all!! At some point in the future you might think about pulling the PTO bell and examining the clutch plate. Might be down to the rivets by now. Easy job to do and good excuse to smear some "Red N Tacky" on the roller bearing. 1 Share this post Link to post Share on other sites
