Woods Finish Mower Issue

[tagslg]

Good afternoon,

I have a Woods RM550 finish mower that has started mowing poorly (see attached pictures). I know the grass is pretty long in the pictures, but I used to be able to mow this height of grass at a pretty fast speed and it wouldn't miss a blade.

All the wheels are set at the same height (4" cut I believe), the blades are OEM part number 18881 and installed correctly, the belt is OEM, I'm mowing at 540 PTO and traveling at a reasonable speed. It was looking like the grass was getting pressed down by the tires and not getting sucked up so I tried OEM 34615KT high suction blades and then some aftermarket super suction blades and that didn't help; might have been worse actually.

It mows poorly even on shorter grass and only does better if I move at a complete crawl. But again, this thing used to tackle tall grass at a good speed and not miss anything. The mower runs smooth, it's not bogging down, spindles seem fine, doesn't have any obvious damage to the baffles, etc. I've had two different tractor repair guys look at it and they couldn't find anything wrong with it.

Any ideas on what could be causing this?

 

[RjCorazza]

That's pretty dramatic. You've tried different blades, so in my mind that leaves something is going on with the right spindle height or rotation.
Can you post some photos of the underside, and take some blade height measurements?

 

[Runner]

Looks like you are mowing extremely tall grass, like more than 10" down to 4". I'm amazed it's doing that well. How does it do on shorter grass?

Kind of looks like it might be a belt tension issue that is letting the right spindle slip or something.

Have you made any changes to rig before it started missing the grass?

 

[tagslg]

Thank you for the replies. Here are some pictures under the mower; I'll get some blade height measurements and deck height measurements and report back later.

Runner, it does okay on shorter grass but still misses if I move at a normal speed; the only time it cuts decent is if I go really really slow. Looks like it might be the forward swipe of the right blade not cutting. Not sure about belt tension or how I would check or adjust that but the belt seems to be in good shape; if it was slipping would the belt be wearing out? I do not have extensive experience working on this type of equipment.

This has been going on a couple seasons now; been trying different things over time and nothing has helped. I didn't change anything on the mower before this started - in the fall it was cutting fine, in the spring it started doing this. However, the first cut I did that spring was way too late and grass was about knee high and this is my only attachment so I had to mow with the 3pt adjusted so the front wheels were up a little bit. But I'm just mowing an all grass field and I didn't hit anything so I'm not sure what that could have messed up.

 

[Smokeydog]

Front of the mower deck should be 1/2” lower than the back. Back wheels tread usually wear faster.

On my woods rd7200 the taper lock that holds the pulley sheave to the spindle shafts has two 1/4”x20tpi bolts that can shear if the blades hit something hard. Causes the blade not to cut as much. Also wearing out the taper.

Belt tension spring does wear out but usually breaks.

 

[tagslg]

Thanks, Smokey, I'll have to look into the manual to see if I can locate the bolts you're referencing and see if I can figure out if they're broken.

All the wheels are set at the same height and I measured the lowest part of the deck edge on all corners: Front Right is 3.5", Front Left is 3.25"; Back Right is 3.25", Back Left is 2.75". (right being the discharge side) On pavement, the right rear tire is just slightly off the ground.

Not sure I did this correctly but I measured the blades with them positioned front to back using the Oregon blade height measuring tool on a reasonably flat driveway; measured near the tip of the cutting edge:
Right Blade: 3 3/8" and 3 5/8"
Middle Blade: 3" and 3 1/8"
Left Blade: 3 1/2" and 3 1/4"

Does any of this look far enough off to be causing the issue I'm having?

 

[careyo63]

I use a RD1060 Frontier 2001. It's made by woods! Your Blades look to be in good shape. I'm thinking the drive belt may not be very tight. High grass and side discharge. I use High lift blades also. ASC AGRI supply Co.. They seem to last longer. Those look to be straight blades and new. I had belts break and wear and that's what my guess is. My Belt tension Is spring loaded and the belt stretch maybe the problem. Thinking I would pull the cover and have a look.

 

[oldnslo]

A poor man’s way of checking for belt slip is to pull the safety covers and then paint a line on all three spindle pulleys referencing a fixed location. Run the mower not cutting anything for a few minutes and shut if off. Check marks on spindle pulleys to see if they are all close to being on same phase. If yes go cut some grass and check again, maybe leave cover off to see if it looks like one of them is slowing. Shut mower off and check pulley position again.

Not 100% fool proof but might provide additional info on cause.

 

[duffer]

Definitely something going on with right side. I agree with oldnslo, test to see if your right pulley is rotating at a slower speed than the left. I'm reaching here, but could the spindle shaft be broken inside the housing? Or maybe the key that fixates the pulley on the shaft is disintegrated or stripped? Can you rotate the blade and hold the pulley in place?

I think someone earlier suggested checking your belt tension. Might be something that easy.

 

[Tinhack]

I'd be leaning toward belt slip. Perhaps caused by worn pulleys. I had to replace the pulleys on my old Woods ZTR mower. It was old when I bought it then used it for another 10 years. I'd probably still be using it (15 years later) if the left trans didn't eat itself. The pic is after I rebuilt the engine and splashed some paint on it.