Loose 8-Speed Drive Belt

[WheelHorseSteve 56]

I'm experiencing a problem on a couple of my 8-speeds -- the drive belt is the correct OEM one yet under any kind of motion-related load, be it a hill or pushing/pulling something, the drive belt slips / smokes at the engine drive pulley.  I've diagnosed this as related to the pulley arm on the left rear of the tractor where the spring is pulling it but the arm still doesn't quite put enough pressure on the idler pulley on the right side to keep the tension high enough.

 

Has anyone else experienced this?  How would you fix?  I've tried adding a small spring on the right side and it stops the slipping but it keeps the belt from stopping so changing gears is near impossible w/o grinding.  Feels like there is a sweet spot somewhere in b/w these levels of tension... I wish there was an easier way to adjust belt tension on these things...

Edited April 8, 2021 by WheelHorseSteve

[Achto 27,751]

It is possible the the spring on the left side is loosing it's tension. Try replacing it with a new one. Should be able to get something close at your local hardware store. I like to get ones that are made with a little heavier gage wire. Makes the clutch peddle heavier but puts more tension on the belt.

 

Also check the roll pins that hold the arms to the shaft that passes through the tractor. If they are warn it may let the arm slip on the shaft, hence not allowing it to provide full tension. 

Edited April 8, 2021 by Achto

[WheelHorseSteve 56]

Thanks Achto.  I did replace the spring, trying both an OEM one and a heavier one and it doesn't help.  That said, I have noticed play in the arm/shaft... I would put money on it being the roll pin(s).  Will check that and report back.  Thank you!

[Lee1977 6,777]

What model Wheel Horse? I drilled out the frame on my C-120 to 5/8" and added brass bushing as the holes were worn egg shape. Never noticed belt slippage but the clutch peddle would hammer when depressed.

Do you have any of the newer Wheel Horses  with the damper on the clutch. I notice Wheel Horse Parts & More has some heaver springs like the older style, that Toro went to a lighter spring.

Edited April 9, 2021 by Lee1977

[The Tuul Crib 7,337]

Check your pulleys as well and make sure the pulleys bearings are ok . They maybe drying up. Another thing I would suggest is to make sure the pulleys are in line with each other.

 

[Tuneup 1,433]

... and the clutch fully depressed activates a plate neat the idler that 'clamps' the belt to the pulley, eliminating any grinding. Does seem that there is wear here or there. You've probably already had the cover off to inspect. Some models need that cover on to ensure no grinding. Yes, what model?