BLADE WASHERS - Thick / Thin / Fact / Fiction / Rhyme / Reason

[Jeff-C175 7,202]

I'm a hopeless pedant. I want to know WHY there are different arrangements of thick vs. thin washers above or below the blade.

 

Maybe nobody else cares.

Maybe nobody knows.

Maybe somebody knows but they won't tell because it's 'tribal' knowledge.

 

But...

 

1980 hard copy part manual I have:

36" SD uses either a thin on top and thick on the bottom, but 'alternate construction' shows thick / thick.

42" uses thick / thick.

48" uses thick / thick.

 

89 42" RD IPL is confusing...  I believe this IPL also covers other models but it doesn't tell you WHICH washer goes with WHICH model

 

 

  the xxx257 is the .030 THIN washer on the BOTTOM,  I don't know if the xxx015 is thick or thin. (can anyone tell me?)  I think that the 015 washer is THICK.  YES?  IS IT?

 

the xxx258 is the THICK washer, on TOP.

 

So they're saying that SOME use thin on the BOTTOM... and some use THIN.

 

91-92 42" RD uses thin / thick

 

95-98 42" RD uses thin / thick

 

Then, there's the SPINDLE CHART that shows that MOST of the spindles use THIN on top and THICK on the bottom...

 

but this one shows the reverse for the 48" deck.

That Z chart is the most confusing to me.  This one is the small hex, UNkeyed metric bearing spindle assembly.  WHY is the washer order reversed between the 42" and 48" deck?

 

This one shows THICK top and bottom with the noted exceptions that use the xxx015 washer which I don't know if it's thick or thin.

It appears from web searching that the xxx015 is the THICK washer and also part number 3526-28 superceded number.  Is this correct?

 

Two thick

 

I'm sure if I looked hard enough I could find more inconsistencies. 

 

It appears to me that the OLDER, KEYED, with LARGE HEX spindles used THICK on TOP and BOTTOM.  Is this the 'rule' ?

 

What's the bottom line?  Does anyone know the reasoning behind the thick / thin blade washers?

 

I would like to know WHY they kept changing their minds.

 

What happens if one uses the WRONG (according to the documentation) washer setup?  Would it even make a bit of difference? What would be the consequences?

 

 

 

Edited July 5, 2022 by Jeff-C175

[EB-80/8inPA 1,653]

7 minutes ago, Jeff-C175 said:

I would like to know WHY they kept changing their minds.

 

 

 

 

 

Drafting errors?

[Jeff-C175 7,202]

1 minute ago, EB-80/8inPA said:

Drafting errors?

 

I thought that, but dismissed it... early on they used the thick washers on top and bottom, and the spindles had the large hex with the keyed shaft.

 

They started spec'ing the thin washer when they went to the small hex spindle.

 

This can't be a drafting error...

 

 

[kpinnc 12,082]

I have a feeling that many of these washers were added during "beta" testing, and became permanent additions afterward on production runs. 

 

Wheel Horse was notorious for using a multitude of parts across different products. I'm guessing to save money- the castings for spindles were bought by the thousands, so minimal adjustments had to come afterwards. Blade height and pulley height as well is probably a result of the same issue. 

[SylvanLakeWH 25,596]

One of the blade design engineers had an uncle in the nearby washer manufacturing plant that had the WH account… or,

 

The parts brochure was outsourced to China and well…

 

[Jeff-C175 7,202]

I'm 99% certain that the 920015 is a thick washer.  I believe this is a photo of the actual part, and the superceded number.

 

 

 

[Horse Newbie 7,072]

@Jeff-C175, the things you mention here have had me scratching my head as well.

I questioned why the thin washers were even necessary, especially when used on top.

It seems to me that the thick washer would hold the blade just fine against the spindle shaft bottom. The only thing I can come up with is maybe the thin washers are used to maybe facilitate “ slipping “ of the blade if you hit a hard stationary object with a blade, and it would keep from bending a spindle shaft.

If that is the case, I guess the manufacturers who use the 5 or 6 (whatever it is) point holes in their blade applications are not concerned with bending spindle shafts.

I’m thinking just do thin on top, and thick on the bottom because the thick washer would have more tightening power, and don’t sweat it… but that’s just me….

anybody else concur ?

Edited July 6, 2022 by Horse Newbie

[Handy Don 12,234]

9 minutes ago, Horse Newbie said:

thin on top, and thick on the bottom

That's what's spec'd for the 42RD I just went through. Seems practical to me, but I rarely have a good sense of the washer positioning mysteries.

[Jeff-C175 7,202]

1 minute ago, Horse Newbie said:

anybody else concur ?

 

I do, that theory is very plausible.

 

It still doesn't really explain the "Z" diagram that shows them reversed between the 42 and the 48.  That's a puzzle still.

 

 

[Horse Newbie 7,072]

4 minutes ago, Jeff-C175 said:

 

I do, that theory is very plausible.

 

It still doesn't really explain the "Z" diagram that shows them reversed between the 42 and the 48.  That's a puzzle still.

 

 

Exactly… puzzling… could keep me awake. That’s how I am ! 

[Jeff-C175 7,202]

2 minutes ago, Handy Don said:

42RD I just went through

 

That's what got me thinking about it here.  The one I just finished only had a single thick washer and I was out of stock on the thin ones so had to buy some.

 

FYI, they are .030 thick.  They can be had from McMaster Carr as 'shim washers' for about a buck each.

[Wheelhorse#1 1,667]

Jeff.Great question.I rebuilt a few spindles a wile back on a RD that called for thin washers on the bottom before the mounting nut.It was paper thin.I too questioned why it was even needed?

Maybe someone at the factory had a sense of humor ?

 

I care .

I definitely don't know why.

And Not part of some secrete club who pretends not to know.

[c-series don 8,719]

I have often thought about this too. I was thinking that maybe the thin washers were for height of  cut adjustment in case one of the spindles got tweaked? Just guessing? 

[Jeff-C175 7,202]

2 minutes ago, c-series don said:

height of  cut

 

30 thou is a fairly minute amount of adjustment though, but you might be on to the reason they are reversed on the 48!  The blade tips on the 48 come VERY close to the rear apron.  A thick washer on TOP would go a long way to clearing that interference.

[Horse Newbie 7,072]

17 minutes ago, c-series don said:

I have often thought about this too. I was thinking that maybe the thin washers were for height of  cut adjustment in case one of the spindles got tweaked? Just guessing? 

 

9 minutes ago, Jeff-C175 said:

 

30 thou is a fairly minute amount of adjustment though, but you might be on to the reason they are reversed on the 48!  The blade tips on the 48 come VERY close to the rear apron.  A thick washer on TOP would go a long way to clearing that interference.

Now here’s my thoughts on these 2 comments…

I think/ know you would NOT be able to see a 30 thou difference in a blade of grass and the blade right beside it.

and…

if you needed to space down the blade with a thick washer on a deck because a designer made a boo boo, and wanted to find the cheapest fix, then I guess they could “ just put a thick washer on top, then it will clear”, but if that’s the case, why not use say a 1/4” spacer ?… but then the blade nut would not screw on far enough.

Oops, now we have to design a longer spindle shaft… nope, just use a thick washer…

[Jeff-C175 7,202]

So, to sum up the thread so far, the washers below AND above the blade may function as a clutch of sorts to alleviate spindle damage in the event one hits something big and immovable.

 

The reason the thick washer goes on TOP on the 48" decks may be for clearance issues between the blade and the rear apron.

 

Sounds good to me!  At least these are plausible explanations!