42" deck - left blade not cutting

[79lilred]

Have a Scotts (Deere Sabre) S1642. The left blade cuts so badly you would think I have the blade on upside down (yep, been there done that before!). Yard looks like a 2-bit haircut when I'm done if I don't go over it for a second pass.
Have sharpened blades and even installed brand new blades. Love the mower otherwise.
Any ideas?
thanks!
-steve

 

[uglyboywith11fingers]

I'm not familiar with that particular deck, but is it possible that you've got the drive belt routed incorrectly such that the left blade is rotating backwards ???
see this link for a diagram showing correct belt routing.
https://groundscare.custhelp.com/ci...2LzEvdGltZS8xMzMyODk2MzMxL3NpZC9vR1JlemFVaw==

Pete

 

[79lilred]

thanks for the reply, Pete!
As well as checking to see if the blade was installed correctly, I did verify it was turning in the right direction also.
Can the quill assy or the belt itself be the problem? I installed new quill assemblies some years ago - 1 came with grease fitting, 1 did not - I installed grease fitting on that one and keep them full of grease.

 

[uglyboywith11fingers]

sounds like the 2 quill assemblys might be different ???
is it possible you've got different cutting height on the 2 blades as a result ?
or perhaps the pulley is sized for a wider belt ?
I can't see the belt itself being the problem, unless it's slipping on the left, and again, that should not happen if the belt routing is correct.

Pete

 

[forgeblast]

I have this problem sometimes, throw a level across the pullys sometimes you hit something and knock it off level, or check where the bolts are going through they might be rusted out. I just bought a new 42c deck my other one was finally dead.
Oh Check and see if the back hangers are cracked and pulling away from the deck thats something that also happened to mine.

 

[joecdeere]

pulley loose on quill? Those pulleys were bad to "spin out" the center

 

[79lilred]

sounds like the 2 quill assemblys might be different ???
Pete

I got both from Deere dealer at different times. I bought this mower new @ Home Depot 10+ years ago. I've replced the quill assemblies a few times - the newer ones come with grease fitting.

I have this problem sometimes, throw a level across the pullys sometimes you hit something and knock it off level, or check where the bolts are going through they might be rusted out. I just bought a new 42c deck my other one was finally dead.
Oh Check and see if the back hangers are cracked and pulling away from the deck thats something that also happened to mine.

Will check each of these - thanks for the suggestions!

pulley loose on quill? Those pulleys were bad to "spin out" the center

without engine running, I can engage the blades belt and turn both blades by reaching under the deck, grabbing one blade and pulling on it, so I think the pulleys are still firmly attached to the shaft. BUT, will take another look as I haven't tried to fix this problem in over a year.

I'm now recalling talking to a Deere parts counter guy years ago when I replaced the 1st quill assy and him telling me that a bad quill assembly will cause 1 blade to spin slower. I replaced that quill assy becasue it was worn out and the bearings shot and just happened to ask him about the uneven cut. I'm now wondering if the quill assembly could be bad even though I keep it full of grease. ...... but wouldn't that wear the belt out or cause it to smoke? Just doesn't make sense that the only symptom of a bad quill assy is the blade not cutting well .........

Really appreciate everyone chiming and helping the newbie out!

-steve

 

[ToadHill]

I'd start by taking the blades off and checking that the positioner, be it a pin, or something else is properly engaging the blade.

I've had situations where the quill spins the blade "ok" at slow speeds but when hgh speed torque is applied the blade slips and will only spin at about 1/4 speed.

 

[cooper99]

Check the spring that puts tension on the deck belt and see how tight it is. I bet that is your problem.

I experienced a similar problem on my GT275 (3 blade 48" deck) last year after about 14 years/~1400 hours. I wish I had a picture to clarify what I'm talking about, but I'll try my best to explain. There would be a burning smell (burning belt) when I was mowing thick grass; it eventually got worse and the right blade wasn't cutting the grass when under load/torque.

I picked up a new deck belt at the dealer, assuming the current belt was just stretched after a couple seasons of use. After replacing the belt, I still had the same problem.

In the process of removing the deck, I noticed the deck belt tensioner spring had almost no tension in it. I remember several years prior, it had been a lot tighter and harder to pull to release. It had no visual signs of wear/stretch, so I didn't want to replace it. However, I needed to find a way to get it pulled tighter.

I'm not sure about the 42" deck, but on the 48" deck there is a metal hook that is welded to the deck where one end of the spring anchors to. There was a small ~1/4" square hole in the deck roughly 1 inch away from the hook. I used a small nut/bolt/washer I had laying around to act as a new anchor for the spring. With the spring having an extra 1-1.5" of stretch, the tension was a lot better and the blades have been working fine ever since.

 

[Yellowfever440]

I think home deploy starting selling these mowers around 2004-2005, just an FYI, I just replaced a spindle/quill assembly on one that was new from a home depot right when they starting selling them. The left spindle was completely out and the right was prettty tight but turned really hard