Woods Finish Mower Issue

[tagslg]

Thank you all for looking at this and offering so much input. Sandman/Smokey - attaching the spindle assembly diagram in case it helps. Is there something I would look for externally or would it be wobbly or making a sound if there was an internal issue with the spindle? I'll try to get the belt off at some point this week and see if everything is still spinning smoothly; it is a spring tensioner so I can't adjust the tension. I can move the belt quite a bit (see pictures) but not sure what is normal - I know the tensioner is tight enough to make it a pain to get the belt back on!

Sixdogs - I think the blades are on correct - the spindles spin clockwise and I attached another picture showing which way the blade spins. Let me know if I'm wrong though.

Eco - I think everything looks pretty straight - attached another picture of the mower for reference and nothing looks too far off to me?

Jaygyver - I'll clean the spindle and see if anything looks out of sorts under there and will get some more blade measurements and report back. Will also check blade bolt tightness. And I agree, I've spent many hours trying to figure out how the mower is managing to cut like this and it has me stumped.

 

[careyo63]

NAPA B116 2 YRs old. Knew I had a problem and found after I removed it. My guess is what your find. On the inside and until you pull it won't know it!

 

[Halftrack]

I vote for a slipping drive belt. Either the belt is shot, or the tensioner is weak, or both. Get a can of Belt Grip and apply liberally. Go mow and see if there is a difference. The pitch (whine) of the deck at 540 should remain the same at no load and under load.

 

[sandman2234]

I vote for a slipping drive belt. Either the belt is shot, or the tensioner is weak, or both. Get a can of Belt Grip and apply liberally. Go mow and see if there is a difference. The pitch (whine) of the deck at 540 should remain the same at no load and under load.

Lol, we used to use belt dressing at a place I worked at if we wanted some down time. Spray on Belt Dressing and an hour later you would loose a belt or two out of the 8 being driven. Became common knowledge, so if you went to the storeroom and checked out a can of belt dressing, they were supposed to call the shift foreman who would come to your machine to watch what you did with it. Not sure if Belt Grip is supposed to do the same thing, but I tend to never put anything on my belts. Adding anything between the belt and pulley is asking for issues in my mind.
David from jax

 

[sandman2234]

Tagslg,
When you pull the belt off to inspect its condition, note the exact position of the idler pulley that is spring loaded. Make sure that pulley with spring isn't at its maximum travel point. Consider adding another spring to help the original pull the belt tight (and keep it tight!!) just to see if belt loosening during mowing is the issue.
If the belt looks good, consider changing it out anyway. Keep the old one as a spare. Just a cheap and easy way to double check a worn belt, to see if that makes a difference. Belts are good at hiding their shortcomings.
David from jax

 

[Runner]

A friend of mine was using a piece of sandpaper to quiet down a squeeky belt by holding it on the inside of the belt with the engine running. Predictable result, got his pinky caught in the belt and it was torn off. Miraculously, Dr's were able to re-attach it and it actually still works fairly well.

 

[Engineer42]

My first thought when seeing the picture of your mower was it's put together backwards, lol. Most woods mowers ive seen, and my 990, the flat side is the front which makes the angled or v side of the deck the back. 550s seem to be the opposite tho, from pics I found.

 

[tagslg]

Thank you for all the advice! I will not be messing with the belt with the PTO engaged! With rain in the forecast, I should have some time this weekend to dig into this a bit more.

Took additional height measurements of the right blade with it positioned side-to-side instead of front-to-back and the outside height was 3.75" and the inside height was 3.25" - is that a concern? Attached are some pictures of the spindle housing underneath the mower - I didn't see anything alarming.

I guess we've determined there is some slipping based on the 'mark the spindle' test but the question I have is if the belt is slipping and that is what is causing this issue, why would it only be missing grass on half the width of the blade? If slipping was the issue, it seems like it would miss grass the entire width of the blade.

I put a brand new Woods belt on it a while back and it did not fix the issue so if it is in fact slipping, I'm thinking it is likely a tension issue. I can check where the tensioner pulley travel is. Sandman, are you suggesting adding another full-size spring to the tensioner or hooking a smaller spring onto the existing spring to help it out. For what it's worth, I did have two tractor repair guys look at this thing and neither said the belt tension seemed loose.

Is there a decent aftermarket belt out there? Hoping not to have to drop a hundred bucks on another Woods belt.

Trying to think outside the box here - if I go through heavy grass, it will miss on the left side of the right blade and also the left side of the left blade (the forward swipe of the blade). The section it misses looks to be in line with the left side of each rear tire. Could the weight distribution on the rear tires be off somehow, applying excess weight to the left side of the tire and mashing down the grass? Nothing looks off and, as I said, high suction blades didn't help the issue so I'm thinking this is not the problem - just throwing it out there.

 

[sixdogs]

At this point, it wouldn't hurt to call Woods and talk with a tech guy or engineer for ideas. I occasionally have called companies when I have a problem or can't figure out something on their product and they have been overly helpful to me.

 

[Smokeydog]

With gauge wheel spindles spacers easy enough to lower the front or raise back about an inch and evaluate the cut. Do the easy stuff first.

 

[tagslg]

You may be right, sixdogs; might be worth a phone call at this point.

I did exchange emails with Woods a while back and their feedback was to make sure the cupped washers were still cupped; if not, they could be allowing the blade to slip on the spindle. The blades are on there so tightly, I can't see how they could possibly be slipping on the spindle. Plus, my question with any kind of slippage is, if the blades are slipping on the spindle, why would it just be missing grass on half the blade and not the whole width of the blade? Maybe it is worth replacing the washers just in case.

They also said it just looked like the mower was having trouble picking up the grass the tires ran over and to slow my mowing speed. If that was the case, I figure high-suction blades would fix the issue but they didn't. As it sits, I can get a decent cut if I travel super slow, like a quarter MPH, but that's just not normal.

Thanks, Smokey, I've tried different height combinations in the past but it's been a while so I'll try raising the back up a notch and see how she does.

 

[leonz]

Hello tagslg,

Judging solely on the two images you were so kind
in uploading to the forum for us to look at it appears
to me that one arbor/spindle appears to have only 2
flat washers and the other arbor/spindle has three flat washers.

If you are not using a torque wrench and blue Loctite
to secure the bolt for the arbor/spindle and a heavy
block of wood to keep the blade from spinning it will slip,
been there done that with the heavy welded 4 caster
Wheel Horse mower decks.

If the compression washers are flat they have lost their
ability to maintain the compression strength to hold the
mower blades in place.

I would suggest to you that you invest in spare compression
washers, a high quality torque wrench and a bottle of blue Loctite
to secure the arbor/spindle bolts and a 4" by 4" or 6" by 6" block of
wood to hold the blades in place.

I have had rotary mowers skip while mowing and the reason that
happened was that the driven belt was either not routed correctly with the
flat side of the V belt under pulley F and under Pulley C in the case of
your R550 and or it was stretched.

The V-belt would stretch and still look normal but would cut as poorly as
your images show us as the pulley with the greater tension would always
cut better.

 

[tagslg]

Thanks, Leonz, if I recall, I believe the cup washers were pretty flat last time I switched blades and likely need to be replaced. When I installed the blades, I used the spindle lock wrench and a block of wood on top of the deck to keep things from rotating. Used a breaker bar with a pipe for more torque to install; didn't use a torque wrench or blue Loctite. I'll see about getting some of these parts ordered and getting a big torque wrench and Loctite.

Even still, if the blade is slipping on the spindle, how would that cause the mower to miss grass on only half of the blade and not the entire width of the blade? I'm not saying it's not slipping, I'm just trying to understand how slipping would cause it to only miss grass on one side of the blade.

 

[leonz]

If that happens and the belt is routed correctly and the compression washers are no longer cupped the V belt is stretched too.
A bad set of bearings will also cause this as the V belt will whistle past the pulley and do as you have seen as well.
If you can purchase a kevlar reinforced V belt it will be much more resistant to shock loading from mowing.
If your mower had 2 blades with 4 cutting edges on each spindle/arbor it would be less noticeable.

You have to keep in mind that only ONE cutting edge is working any time the mower is mowing as it advances. and if it is not
spinning as fast it will simply push the grass blades over.

 

[sixdogs]

I do recall those cupped washers on my Woods mower. I recall changing them frequently. Maybe once or twice a year and not sure why I did it. Might be worth looking onto.

Blades don't either 100% slip or 100% not slip but rather slip a little here and there. I could see that look from slipping blades maybe from incorrect torque on the nut or those washers. The problem has to be something simple.

 

[sixdogs]

Any updates?

 

[tagslg]

Thanks for checking in, sixdogs. My schedule hasn’t let me get after this as much as I was hoping but this past weekend I did get new cupped washers on there, blue Loctite on the bolts, and sharpened the blades. Still need to get a torque wrench to be sure, but I’m using a two-foot pipe for added leverage to get those bolts on pretty dang tight – they need to be 175ft. lbs.

The belt seemed a little loose to me but I didn’t have time to pull it. As a temporary fix, I strung a large zip tie through the tensioner spring and tightened it down which seemed to add a decent amount of tension. The belt may still be looser than it should be; not really sure what I’m looking for as far as belt tension goes.

In any event, this did not solve the problem.

Guess the next step is to replace the belt and replace the spring to rule out any belt tension issues? And when I have the belt off I can make sure all the spindles seem to be in good order as well. Any recommendations on an aftermarket belt that won't fall apart?

 

[Halftrack]

I was wondering if you had resolved the issues with your deck. If not, I have additional input.

 

[chim]

You're cutting too much off, plus mashing tall grass down makes it hard for the deck to deal with.

 

[pmsmechanic]

OP a while back (page 2?) you mentioned that one of the drive pulleys was smaller that the others. If you are using the stock length belt it could be that the drive belt is a little too long for the smaller pulley and the belt tensioner is not capable of keeping the belt tight enough. I'm reasonably sure that all of the spindle pulleys should be the same diameter. It wouldn't hurt to check up on this in a parts book.