Mortimer Schnerd wrote:
....
loosening the two end caps that actually hold the blades on: forget it.
I couldn't budge any of them.

Looking in the owner's manual says they're supposed to be torqued to 42
ft-lbs. Well, even using a piece of pipe as a cheat, I got nowhere. Are
these things reversed threaded? Is there a trick I don't know? I was
using a 1/2" socket wrench with a 15mm socket. Maybe I need to move up
to a bigger wrench?
....

Remember hitting anything?

It's possible you've stretched the bolts which has the effect of locking
them in there like the blazes. Managed that w/ the outside blade on the
72" deck last year; took about a 4-ft cheater and initially bent a 1/2"
small pry bar had used as the lock through the drive sprocket to hold
it. Had to get a stouter stop...

Heat/cool can help on this; heat alone only makes this problem worse
because it's a mechanical distortion problem and swelling the bolt by
heating it only tightens it even further. When it cools after a heat
cycle it may help some.

If it is this problem, the only real solution is bigger wrench. As
somebody else said, go to a six-point socket to minimize the likelihood
of rounding them over 'cause if you do, you're toast.

_IF_ (the proverbial big if) you have a good-size knick in the knives,
that'd be a clue--I didn't recall hitting anything I thought was
significant enough to have caused the problem but w/ that larger mower,
sometimes you don't realize what you've gone over in heavy brush. In
that case, you might consider taking it to the JD dealer simply to put
the onus on them if twist one off. They're hardened, but I was really
beginning to wonder before this one came out finally. It was amazing it
could have stretched and distorted the threads so much while in
place--never seen it to such a degree before in 60-something years.

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