Mountfield 1440M - Toothed Timing belt keeps snapping

[Raynbow]

Hi, recently new to owning a ride on mower so be gentle

I've a Mountfield 1440m and its toothed timing belt has snapped. Just replaced it and it was working great, then after half an hour it snapped again. It seems to have frayed then snapped and left a right mess under the plastic cover - see photo. Pulleys etc are all spinning as they should and tension was just spot on. Any ideas what could be causing it? Any and all help greatly appreciated

 

[StarTech]

Need a photo of it installed as it looks like might had been installed incorrectly. Belt rubbing on something probably

Or you just defurred a mouse/rat. (just kidding here)

 

[Raynbow]

Need a photo of it installed as it looks like might had been installed incorrectly. Belt rubbing on something probably

Or you just defurred a mouse/rat. (just kidding here)

Don't laugh, but for a second I actually thought a rodent had got in when I first opened the cover

I installed it to the layout in the workshop manual. Checked everything was moving, blades spinning etc, belt seated correctly, all seemed fine. Just thinking I may check the rollers again to see if they are spinning freely, 11 and 12 on the diagram. Waiting on a new belt, will come back to you in a few days once I get it fitted and see if you can spot a problem.

 

[StarTech]

No problem. Just got double check things. Just be aware when checking pulleys if you feel any rough spots, catches it can cause a pulley to lock up under load. And problems like this might take a few tries to find the source too. I had one machine that would only snap the v belt here after a few hrs of use. Finally found one idler bearing with a slight catchy stop, replaced it the problem went away. Now I always turn the bearings feeling for this problem and replace them when I do feel it.

Also it could be a belt rub in the area but on what.

Experience does helps at times.

 

[Raynbow]

No problem. Just got double check things. Just be aware when checking pulleys if you feel any rough spots, catches it can cause a pulley to lock up under load. And problems like this might take a few tries to find the source too. I had one machine that would only snap the v belt here after a few hrs of use. Finally found one idler bearing with a slight catchy stop, replaced it the problem went away. Now I always turn the bearings feeling for this problem and replace them when I do feel it.

Also it could be a belt rub in the area but on what.

Experience does helps at times.

Thanks for the advice. I'm going to take the whole deck apart and learn it's inner workings

 

[Raynbow]

Got the deck stripped down and it looks like the locking pin was jammed and all of the 4 plastic bushes on spindles have been fairly worn down. Have those on order and suspect there is a washer missing from the locking pin. I'll get it all stripped down to the nuts and bolts and clean and lubricate everything and see how it goes.