How to tell if rear mowing deck belt needs replacement?

Ezzrider · Jul 29, 2011

I have a B7510 with a Land Pride FDR 1660 rear mowing deck. I just replaced the blades (with help from this forums members) and my cut still was not great. The old blades were shot!! The mowing deck does not sound right when cutting. Hard to explain. I took off the deck covers to expose the belts and noticed the belt was wobbling at the top pulley. It does not squeak and does not appear to be slipping. I tightened up the belt tension eye bolt as tight as I could and the cut was better but the odd noise was still there and the belt was wobbling. I grease my pulley fittings on each use of the mower but I guess I could have a bad pulley bearing? Any ideas? The belt costs $75.

SSdoxie · Jul 29, 2011

Was the just pulley wobbling or was the blade spindle wobbling. I just went through similar problem with my little Sears rider. Was getting a wierd looking cut on 1/2 of the deck, found 1 bearing in the blade spindle was completely shot, only thing keep blade up was the other bearing and belt tension. New spindle bearings and everything is fine.

groundcover · Jul 29, 2011

Sounds like it could be a bearing or it got hit and bent. Run it for a bit and check each spindle temp. Might point you to a bearing if one is hotter than the others. I would think as long as the belt isn't slipping it would be ok. Good luck!:thumbsup:

KennyV · Jul 30, 2011

Take the bolt OFF... rotate each pulley by hand... you will feel any bearing problem... also reach under the deck and try to lift up on the end of each blade... there should be NO movement up & down at the blade ends...

If you know your belt size, you can order them on line for less than a third of the price you paid... KennyV

Ezzrider · Jul 30, 2011

KennyV said:
Take the bolt OFF... rotate each pulley by hand... you will feel any bearing problem... also reach under the deck and try to lift up on the end of each blade... there should be NO movement up & down at the blade ends...

If you know your belt size, you can order them on line for less than a third of the price you paid... KennyV

Take which bolt off? The bolt on top of the pulley? I can rotate the pulleys by hand turning the belt. Did you mean to type take the belt off? I have not purchased a new belt yet. I just spent a couple of hundred dollars replacing the battery and 3 blades. Did not want to spend the extra $75 on a new belt unless I was reasonably certain the belt needed to be replaced. I do have a little over 6 years on this belt. It is the original belt that was on when I purchased the tractor in June 06. Since I just replaced the blades I don't remember any movement up or down but I can check again. I can push on the belt and it moves about 3" or so for slack but again I do not hear it squealing or slipping. Maybe it is a pulley bearing.

TripleR · Jul 30, 2011

You should be able to tell belt condition by looking for cracks and feeling how hard/brittle it feels. When I was using a RFM, I have run a belt until it came apart and was getting a good cut until it let go.

LD1 · Jul 30, 2011

TripleR said:
You should be able to tell belt condition by looking for cracks and feeling how hard/brittle it feels. When I was using a RFM, I have run a belt until it came apart and was getting a good cut until it let go.

Yep, when they break, thats when they need replaced.

What I do, If I notice a belt starts to look bad, woen, cracked, etc. I will go ahead and pick one up. But I usually wait until the old one fails completely. That way I know I am getting the absolute most life out of it.

As far as the other problems, HArd to say. As others have asked, is it the belt or do you have a bent pulley? Perhaps you could try to upload a video of it running??

But even if it has bad/nousy bearings and a bent pulley, if the belt aint slipping, you should still have a good cut, as the blades are turning asfast as they can. The only other thing I know that could cause a bad cut would be if the underside of the deck needs cleaned. If it has layers of packed grass under there, it causes the air-flow under the deck to do some weird things and not lift the grass blades up as it should.

rbargeron · Jul 30, 2011

Ezzrider said:
How to tell if rear mowing deck belt needs replacement?....... I can push on the belt and it moves about 3" or so for slack but again I do not hear it squealing or slipping....

A worn bearing won't affect the cut unless its bad enough to stop turning.
The belt could be slipping without making much noise. It could be loose, or worn so that it's riding in the bottom of the pulley grooves. Does the "hum" of the blades change under load? Spray belt dressing might help for a while. If so you'd know where the problem is.

TripleR · Jul 30, 2011

LD1 said:
Yep, when they break, thats when they need replaced.

What I do, If I notice a belt starts to look bad, woen, cracked, etc. I will go ahead and pick one up. But I usually wait until the old one fails completely. That way I know I am getting the absolute most life out of it.

As far as the other problems, Hard to say. As others have asked, is it the belt or do you have a bent pulley? Perhaps you could try to upload a video of it running??

But even if it has bad/noisy bearings and a bent pulley, if the belt ain't slipping, you should still have a good cut, as the blades are turning as fast as they can. The only other thing I know that could cause a bad cut would be if the underside of the deck needs cleaned. If it has layers of packed grass under there, it causes the air-flow under the deck to do some weird things and not lift the grass blades up as it should.

Agreed, we have completely lost bearings and except for the noise, it still worked fine. We had one set seize up and spin on the shaft and wear it down. We had to use JB weld to hold the new bearing and ten year later it's still holding.

The poor cut quality is puzzling with new blades asuming they aren't slipping on the spindles.

sandman2234 · Jul 30, 2011

I think he meant to take the BELT off, not the bolt, a simple typo. Remove the belt from the pulley's, so that you have a non tensioned spindle to compare the other non tensioned spindle to (or 3 or whatever your deck has). Removing the belt lets you "feel" what the bearings are doing and any movement in the spindle can be felt. Hard to do when you have the belts on with them keeping the spindle pulled against one side of the bearing housing.
If you are paying $75 for a belt, consider measuring the belt length, determining the width and shopping around for a different supplier. Just because it is brand X doesn't mean you can't buy brand Z belts if they fit AND are from a quality manufacturer. Most tractor and lawnmower manufacturers buy their belts from somebody and quality isn't allways the final consideration.
I buy my lawnmower belts from ebay, at five times less money.
David from jax