I've got my Toro Zmaster 3000 series that I've been running strong for 7 seasons now. Just within the past two months is been going through belts. I've been using Stens and I've always had food luck with them. Now's I'm going through a $70 belt every 3 weeks until this one which lasted 7 days (well, it hasn't broken yet but it's cracked at the seam and won't last very long).

The spindles get hot to the touch, the idler pulleys don't. Hot spindles is normal but I don't know how hot is normal. The laser thermometer says they're at 145°f. The belt is at around 130°f.

When the idler pulleys go they smoke and stink. I've broken a spindle before but have never worn one out.

Spindles and idlers spin freely, no grinding. Spindles don't continue spinning much by hand. Not even a complete revolution.

Replaced the blades in case one was bent.

New blade clutch that grabs really hard.

I'm lost and can't find a reason that I'm destroying belts so quickly. Any other ideas to look into?

Since you're running though belts and didn't before it's either

1) Belt company product now is made in a factory in Guang Zui with lower quality materials, or.

2) you have a pulley problem, either bad bearing, bent shaft, misaligned pulley

My guess is you have a mechanical problem not a belt problem..

quote:

Originally posted by HRK:
Since you're running though belts and didn't before it's either

1) Belt company product now is made in a factory in Guang Zui with lower quality materials, or.

2) you have a pulley problem, either bad bearing, bent shaft, misaligned pulley

My guess is you have a mechanical problem not a belt problem..

I'm thinking the same thing but I can't find an issue.

Well you could change belt companies, that would eliminate the manufacturer and confirm that you have a mechanical problem, however I doubt you have 30 more days of mowing time left in PA LOL

Have you googled the deck manufacturing specs for runout on the blade/pulley assembly, seems like pulling the deck and checking the runout is the next step, perhaps with the deck out and up on blocks turning the pulley by hand you might be able to find the issue, you can at least get the blades off for sharpening and inspect the pulley and bearings.

With the deck out, and hand turning them with no pressure from a belt you might hear or feel the problem. It's tough to detect that stuff when a vibrating running engine is there...

I'd bet you hit something, even the ground hard enough that it's caused misalignment, or the alignment pulleys are out, running the belt out of position.

Bent deck, spindles, idler pulley. If you don't see the issue, it's time for a trip to the dealer. This is your livelihood, correct? How much downtime can you afford tracking it down yourself?

Do the pulleys have zirk fittings? If so have you lubed them?

Worn sheaves? My experience is that these wear faster than bearings, and the drive sheave usually wears faster than the driven sheaves which wear faster than the tensioner.

I've also seen the mounting deck warp so that the blades are not parallel to the ground. This of course angles the sheaves which will wear belts quickly. This is usually immediately obvious due to its effect on the cut.

Remove the belt and turn the pulleys by hand.
Besides bearings, I've had all sorts of stuff (vines, rope, etc.) get wrapped tightly around rotating parts resulting in very high resistance to turning.

It definately sounds like an alignment or mechanical issue. I would try a different brand belt to rule that out. But, would also measure alignment of the pulleys and belt when it has tension on them......A bearing may be going bad and allowing the alignment to be off once there's tension on it. If you can make an appointment with the dealer, where they'll get right on it as soon as you drop it off, that's what I'd do rather than trial and error.

Can you use a straight-edge to verify alignment between the pulleys and idlers?

I had a deck that got twisted a little, and it would throw belts like crazy. Would get very hot from the additional friction as well.

I was able to shim the worst of the pulleys and it helped quite a bit.

Bad spindle bearings...wearing.

Causes the spindle to "lean" ever so slightly...enough to throw the pulley out of parallel and eat belts.

I didn't have an issue with my cub spindles...so I thought. Replaced all three and my belts are lasting years now.

I grease the spindles very often now...keep them packed or they will wear again.

Spindles. From your description you have excessive friction.

I had the belt off today. There is no play in the bearings, there is no grinding, everything spins seemingly freely.

I would imagine the sheaves are well worn after 7 full seasons. I have a backup mower but I'll never be able to finish the year using it. I'll take it with me from now on though.

quote:

Originally posted by Patriot:
Bad spindle bearings...wearing.

Causes the spindle to "lean" ever so slightly...enough to throw the pulley out of parallel and eat belts.

I didn't have an issue with my cub spindles...so I thought. Replaced all three and my belts are lasting years now.

I grease the spindles very often now...keep them packed or they will wear again.

wouldn't i be able to feel some play in the spindles?

quote:

Originally posted by trapper189:
Bent deck, spindles, idler pulley. If you don't see the issue, it's time for a trip to the dealer. This is your livelihood, correct? How much downtime can you afford tracking it down yourself?

This, with Spindles being the most likely. Between managing a lawncare company and a golf course, the company I work for owns and has owned a decent number of Z masters. We kill spindles more than anything else aside from normal wear items. We’ve had guys bend the deck, but that usually makes the blades hit so we know right away. We lose pulleys on occasion, but we lose spindles much more often.

- Bret Sadler

Spin everthing with a bearing you can and listen for noise. Also push up and down where bearing are looking for excessive slop.

quote:

Originally posted by mark123:

quote:

Originally posted by Patriot:
Bad spindle bearings...wearing.

Causes the spindle to "lean" ever so slightly...enough to throw the pulley out of parallel and eat belts.

I didn't have an issue with my cub spindles...so I thought. Replaced all three and my belts are lasting years now.

I grease the spindles very often now...keep them packed or they will wear again.

wouldn't i be able to feel some play in the spindles?

Maybe, once you get the belt off spin them one at a time, the problem is that it just might be once the blade is engaged and the rotation speed up that the situation gets past spec.

Depending on the use per year in hours and the total hours on the deck, might be time to RNR the spindle/bearings anyway and sharpen the blades while old man winter is here...

Spindle bearings too tight or misaligned for some reason. They shouldn’t “rattle” when the blade is used as a lever to check for slack, but they should also be rather free spinning.

See what the dealer says. Take the lead and lesson from him.

Or replace the bearings yourself. See how new ones spin compared to the old ones.

I don't know much about mowers, but I know about belts. What does the belt drive? What type of belt? (vee, flat, cogged). What happens to the belt when it fails? Is it snapped clean in two? If snapped, do the ends look burnt and/or does the belt feel stiff for the first few inches on either side of the break? Delaminated? Shredded on the sides?

This message has been edited. Last edited by: egregore,

Does your machine require more than one belt? My machine requires a “banded” pair of belts to avoid problems.