Uneven mowing

I have a 1995 craftsman 42" mower model # 917.256520 thats mowing uneven - one blad cuts higher then the other. It looks like the mower itslef is tilted. I havent put on blocks to get under it yet but my assumption is that there are bushings of some time that may have given out.

Is this a common problem? Anyone have other thoughts idea's?

 

There is a common problem with the green Craftsman 42" mowers.
If the deck or blade hits something like a rock or stump, the left portion of the deck, which the mandrel attaches to, will distort or bend down some, towards the 2-3 o'clock direction.

They even have a tool, DS-100, $150, that will help straighten it back.
If you know for sure the deck or blades have not struck some immovable object, it is probably something else.

You can tell by stretching a string across the two pulleys. If the inside of the left has a space between it and string, the deck is distorted.

I devised a method where I can get it even in 5-10 minutes, costing nothing.
hth

 

There's nothing under there that will wear out and effect the height of the blades more than 1/16 of an inch.

You can park it on level surface and simply check the ground clearance of each side of the deck.

Or see the nut right in the center of the photograph?
There is one on each side. If you see the same amount of thread under each one - your deck is level.



It could also be that the aluminum castings (mandrel housing) that hold every thing from the pulleys to the blade - is cracked were it joins to the underside of the deck. Or as Glen suggests maybe just bent. If that's the case you'll see a blade pully that's out of plane and pulling a dip in the belt as you view it from the side.

 

tire pressure differences can also affect cutting level.

 

Exactly, equal tire pressures should be first to do, I usually make sure each tire has 10 psi.
thanks,

 

Thanks GlenM - I dont have the green 42" but I did hit a root from a maple tree that must have grown over the winter/spring that stoped me dead in my tracks. And it is the left side (as you sit on the mower) that is hanging lower. I'd be interested to hear this method you devised...

I will also check the nut mickblock suggested. I took a quick look last night and didnt notice anything but I wasnt looking for anything specific and only had a few minutes so I will look again.

Thanks for the suggestions!

 

917.256520 is not recognized by searspartsdirect.com, one of them last 6 digits is incorrect.
Do you have an owner's manual for this unit? you can get it off the sears site.

I'd like to see IPL of unit before i give instructions on how to straighten deck, if you can doublecheck mod. no. (altho it's probably the one I'm thinking of, even tho it isn't green)

I'm used to the green ones like posted previously by mickblock.
thanks,

 

I was never able to find anything on the sears website (maybe because its over 10 yrs old?) but I did find schematics/user manual here: http://www.outdoordistributors.com/p...PARTS-LIST.pdf

I checked the bolts mickblock suggested and they look like they are level so it looks like you may be on to something.

 

Well, it looks like the green Craftsman's...
Anyway, this is what I do to straighten the deck up.

It's best to remove the deck.
You have to make absolute sure the blades are straight.

Remove the plastic mandrel guard from left side, has 3 screws.

Loop and hook a small log chain around mandrel under the pulley, loop is just big enough to extend a coupla inches outside deck on left side.

Now, I have real heavy 5' pry bar that is 1 inch sq at bottom part.
Make sure blades are tip to tip on deck underside.
Put bar inside chain loop, outside of deck, where you are pulling mandrel back toward the 7:30-8:30 o'clock position.
pull chain up to be touching bottom of pullley and pull on pry bar. using end of deck for leverage.
You can see mandrel and deck coming up.
check blade tips for evenness.
to get the tips close to even I have to have someone stand on the right side of deck to hold it down.
don't be bashful on pulling back on the pry bar, just check several times the blade tips.

Anyway, that's how I do it, just did one last week.
hth