New blades make intermitten noise

[justplain bill]

Just put some new Gator Blades on my Troybilt Bronco. Old ones were fine, just needed sharpening. The new blades make a metal to metal noise. Put the mower on my mower lift and couldn't find anywhere that they were hitting. Mower had been cleaned and scraped of all old grass build up. Took new blades off and still could find no metal missing from under the deck or from the new blades. This is after mowing my whole yard, which about three quarter an acre. Put my old blades back on after sharpening and no noise. Can anyone help me solve this mystery?

 

[keakar]

some decks use fixed blade positions and some dont, put the blades on in opposite angles with one east to west and the other north to south and that should fix it if its the blades hitting

but it has to show a bare metal spot or "something" where its contacting on metal. also be sure any metal filler plates under the deck (if you have them) are secured and not moving around to be able to hit the blades.

also check close if the spindles are loose or possibly have a cracked ear on one, if you are hearing metallic sound then pull the deck and flip it over on some saw horses and turn it by hand until you can see the problem

 

[justplain bill]

Metal filler plates???

 

[keakar]

Metal filler plates???

these things https://www.ebay.com/itm/Husqvarna-...rand=Husqvarna&_trksid=p2047675.c100005.m1851

i find they are often loose and/or bent and they can hit the blades

 

[StarTech]

Or it could simply either the spindle bearings are worn or the blades are tad too long. Had a Murray years ago that would tag the blade every once a while ground a little off the offending tips and the problem was resolved.

 

[tom3]

Do the blades fit tight on the mounting bolt or fit in a star shaped spline of sorts. Maybe one didn't get exactly right and being off balance cause some noise in the spindles or belt tensioners. Odd problem for sure.

 

[justplain bill]

I will check all of the above advice. Still have the mower on the lift. Appreciate the help.

 

[bertsmobile1]

If a blade is hitting something then the end of the tips will have polish marks where they are hitting
Otherwise the only polished spots should be the cutting edge and the bend in the flute.

 

[justplain bill]

By George, you are right. There are a couple of places on each tip where the paint is missing, (worn off) that is probably where it is rubbing. Now I just need to come up with a solution. Thank you so much.

 

[bertsmobile1]

Try to rock the blades see-saw style
Any movement what so ever = new spindle bearing time
or even worse, new spindle housing time if the housing is cracked around one of the mounting bolts
or deck welding time, if it is a older deck and the deck is cracking around the spindle housings.

If none of those the take the blades off and very lightly grind back the area where the blade is kissing.
Do both blades and be frugal if you take too much off you will kill the blade overlap sp will end up mowhawking .
Make sure they are both balanced before you refit them