Mower Deck Airflow

[JBavo686 0]

Bought a 312-8 used 18 yrs. ago with 37" deck. Last five years I have noticed a steady decline in mowing quality - more and more uneven. In the same timeframe I noticed the gradual erosion of the vanes on the underside of the mower, which I always assumed were there to control airflow. They are completely gone now. Speculating there is some correlation between the vane erosion and cut quality, I took the mower to the local (former) Wheelhorse dealer, who still repairs quite a few Wheelhorses. They had no idea about the vanes, and could only recommend new blades.

Is this a common problem, and is there some way to remedy it? If there is a description on the configuration of the vanes I would bring it to a local machine shop and get new vanes welded on, because otherwise the deck, and tractor, are in very good shape. I would hate to have to buy another tractor, particularly since they don't make Wheelhorses anymore.

Any help would be appreciated.

[Duff 206]

:USA: ! Glad to have you with us, and you've certainly come to the right place for all things Wheel Horse!

The "vanes" are indeed part of the airflow "tunnel" system that makes the 37" SD deck one of the best cutters WH made. If they've worn or broken off it will certainly affect the quality of cut, with or without new blades (although either needs to be sharp!). If you have access to someone with sheet metal fabbing skills, it's a pretty simple matter to build and attach some replacements (I assume the shell metal on your deck is still sound?).

When I get home tonight I'll snap some pictures for you of the vanes under my 37" SD deck (I've got it off for service) to give your local shop some idea of what they need to build. It should be a realteively small and easy job.

For Heaven's sake, don't even think about buying another tractor ....unless it's another Wheel Horse and you are building your herd like many of the rest of us!

Just an afterthought....are the rear wheels on the deck in good shape and is the lift/suspension assembly OK? If one or both of the rear wheels are shot it, too, will affect cut quality, as will a sloppy lift/suspension assy.

Duff :D

[JBavo686 0]

Duff -

Thanks for the prompt reply. Yes the deck seems to be very solid, should be no problem welding to it. I don't know about the suspension - I've been clipping the deck on the same way for 18 yrs. and haven't noticed a difference. But I'll check it now - anything in particular to look for? The right rear deck wheel seems to squeak a lot. Never took very much grease. But it spins.

Thanks for the help.

[rick 255]

I would like to see the vane configuration, too. My 37" deck has none, it had a small vestige left when I got it, but it "disappeared" during the remake job.

Deck seems to cut well, though.

[Duff 206]

OK, guys, here's my poor attempt at giving you pics of the baffles with some measurements:

Here's a view of the entire underside of the deck:

This is the width of the open side of the "V" of the baffle (16")

This is the distance from the rear of the deck shell to the point of the "V" (7")

Closer view:

The baffles hang about 2" from the deck shell into the blade area

This "mini baffle" hangs above the left hand (as the deck is hung on the tractor) or "inner" blade.

Better view of the "mini-baffle". Not sure of its purpose but since they built it, it must have some value!

Close-up view of the baffles

Hope this is of some help to you folks!

Oh - the deck lift mechanism. It has some "slop" by nature to aloow the deck to follow the contour of the ground but it shouldn't be excessively loose. Rear wheels should still show at least a little tread and not wobble on their axles.

Duff :D

[WH854 45]

:USA: Looks like a good job to me Duff. Good set of pictures and good description makes sense to me!

Chas

[rick 255]

Thanks, Duff. The "mini" baffle is the one that's gone on my deck.

[bo dawg 517]

Nice job Duff!

JBavo686

[wh500special 2,263]

Holy smokes, Duff. You eatin' off that thing?

That's a clean machine.

Regarding cut quality:

The 37" deck has a side-to-side adjustment for the rear gauge wheels that needs to be adjusted level to prevent grooving the turf. If you have a wheel that is hanging up, is drooping, or is misaligned perhaps that's contributing to the problem.

The 37" deck is the best cutting deck WH made in their pre-Toro days. Cut quality is somewhat subjective, and I'm not exactly sure what symptom you're having. Hopefully Duff's posts point you down the right pathway.

Steve

[Duff 206]

Holy smokes, Duff. You eatin' off that thing?

That's a clean machine.

Thanks for the kudos, Steve. I try to keep my equipment in good shape.

As a matter of interest, at the beginning and end of each season I wire brush the underside of the deck and brush on clean bar and chain oil. During the season I simply hose off the underside with a garden hose and pressure nozzle (but not a pressure washer, although I've got one) at the end of each mowing day. While I'm spraying the underside I run the deck at about half throttle so the blades help to accelerate the water spray and really wash the surfaces. I've had no problems with rusting whatsoever.

Those pictures were taken just after I'd wire brushed and applied fresh oil. I had just used the deck to "brush hog" a piece of land between mine and the neighbors that had grown up to finger-sized saplings and weeds. Flattened and mulched everything beautifully (Gator Blades are THE BEST!). I figured the coarse material I was hogging might have stripped off some of my oil coating. Normal grass mowing doesn't seem to bother it.

Duff :D

[rickv1957 74]

Great job there Duff! Rick

[rickv1957 74]

JBavo686 Rick

[JBavo686 0]

Duff et al -

Spent a little time investigating and found ....

First of all, the only vane I see in your pix that I don't have is the little 'mini baffle' on the left hand blade. I could have sworn there were more items that rusted off but hey that happened some time ago. And those are some interesting blades you have there - where'd you get them? What difference are those serrations supposed to make?

And - wh500special is right - that deck is scary clean. I thought maybe you did that just for pix, but its that clean all the time?!?

Being more specific about the uneveness of the cut, the left hand blade seems to cut much better than the right. The worst spot seems to be a narrow little ridge, couple inches wide, right about where the two blades almost meet. When I first bought the new blades, I noticed that 1) the new blades seemed wicked expensive 2) the new blades were somewhat longer than the old, and 3) that little ridge was reduced somewhat, but the rest of the problem was not.

So after cleaning the deck a little more, and putting one of the kids on the tractor so I could observe the deck in action, I noticed the grass being 'rolled down' right behind the leading edge of the deck where the grass dicharges. Its just as if there were an invisible roller mounted under and just behind that leading edge.

Thinking that maybe the 'roller' was due to the grass being bent by the leading edge of the deck, I raised the deck a notch (cleaned it again) and had my daughter go back over the already mown grass. The roller was still there, despite none of the grass being touched by the blades or the deck.

The roller is right where I'd expect the highest air velocity from the discharge. So I'm convinced that the stream of air there is 'rolling down' the grass so the blade doesn't hit it. Maybe that one mini-vane, despite being on the left instead of the right, disrupts that roller from forming. If you notice in your pix the right hand side has more of a discharge tunnel, which I think enhances the roller and would explain why the right is worse than the left.

Well, enough talk and observing. I'm going to clean the deck and then get that vane welded back on. After I try it out and clean it I'll report back.

Seriously, thanks for the help and motivation to run this thing down.

[rick 255]

I am curious about your mowing speed. I have the same deck on my first Wheel Horse, a 310-8. I am also missing the "mini vane". I mow in first or second gear in Hi range, with Wheel Horse blades, and get a very good quality of cut. My yard is mostly "native grasses" and weeds, so that maybe the difference.

[Duff 206]

First of all, the only vane I see in your pix that I don't have is the little 'mini baffle' on the left hand blade. I could have sworn there were more items that rusted off but hey that happened some time ago. And those are some interesting blades you have there - where'd you get them? What difference are those serrations supposed to make?

Sorry - I'm not sure of what purpose the little vane serves. Looking at my deck, it might help to divert the clippings into the outflow tunnel rather than allowing them to build up in the circulation of the left blade. Just a wild guess, though!

As to the blades, they are "Gator Blades", a commercial quality (but amazingly inexpensive) mulching blade with sizes to fit a wide variety of tractor makes. They're rapidly gaining favor among users. I have them on three different tractors and they out-cut anything I've ever owned. They also hold an edge amazingly well. The little serrations have something to do with the air flow they generate to repeatedly direct the clippings into the path of the cutting edge of the blade, thus reducing the clippings to a finer consistency. According to the manufacturer it's not necessary to sharpen the serrations, as they aren't part of the actual cutting process. I highly recommend them!

Duff :D

[JBavo686 0]

Rick -

I cut 95% of the time in Hi-2nd and the remaining 5% in Hi-1st. When I first started noticing the problem I did the entire yard in Hi-1st but no real difference. I typically set the deck on the second highest notch. Throttle just about maxed out.

I don't typically have the detachable wings mounted on the blades primarily because I don't use the grass catcher. Having them attached doesn't seem to help or hurt the quality of cut.

I have noticed that if I drop the deck down the effect is reduced, but my grass doesn't like being that short. What setting do you use?

Duff - I'm liking the look of those gator blades. Think they would have them at the local home improvement big box?

[Duff 206]

Duff - I'm liking the look of those gator blades. Think they would have them at the local home improvement big box?

Probably not, and my previous supplier isn't listing them any more as a Toro/Wheel Horse number. I'm doing some research and may have found the same critters for a Cub Cadet application. As soon as I have confirmation and a part number/supplier I'll post it here.

Cheers!

Duff :D

[rick 255]

JBavo686- thanks for the reply.....I cut at the same height setting, but use Hi-1st more than half of the time. My blades are not made for the wings, they have the standard

turned up rear corner. I have to say that this deck seems to shoot the clippings out with more velocity than my 42" deck does. I even have the deflector chute bolted on!

[Butch 194]

I like the folding wooden ruler!! I have one sitting on my desk next to me. I use it more than the half dozen tape measures I own!! It was also my dads favorite.

Butch

S. Jersey