Best fix for 90" mower

American Bulldog · Oct 17, 2010

I have not really started beating on the mower yet, and it is already letting me down. When a blade hits something that it can't go through, it swings back and hits the mounting bolt 90 degrees behind. After a few hits, the mounting bolt breaks. I know there have been threads about this, but on short searching I was not able to find them. Please help me with some advice. Change mounting bolts to Grade 8? Go with different blade?

There are three cutting heads on the 90" mower and the two outside heads both have broken one bolt.

frischtr · Oct 17, 2010

Try this thread: http://www.tractorbynet.com/forums/power-trac/139566-brush-cutter-backstops.html

American Bulldog · Oct 17, 2010

Perhaps we should ask Terry what to do. Maybe his advice would be to not use the mower at all, and then the bolts won't break, lol. At least he can't say that this is the first he has heard of it.......

I only have about 4 hours of mowing on this thing. One word, UNACCEPTABLE.

woodlandfarms · Oct 17, 2010

Eyup.. Welcome to the PT large mower conundrum.

Read that link, lots of useful info.

But two things I have found. First remove all the "stop bolts". They are NOT stop bolts, just bolts to put new blades on when you break yours off.

Put in hex bolts that are inset (They look like a plug with a hex key end). This way the threads stay nice and clean and you don't break off the stop bolts.

Second, carry a hammer. This isn.t just a bad PT design, it is a problem that happens on a variety of brush hogs.

Getting those bolts out is a bugger. I take a 4" angle grinder and cut a gash on the bolt, then use a flat head screwdriver and unscrew it (or a hammer and a punch).

And for sure do not have any stop bolts on the front (center) mower. It is direct drive and I can guarantee you it will break. Lots of torque.

Carl

MossRoad · Oct 18, 2010

And when you order yourself 2 new sets of replacement blades (because you WILL lose them sooner or later) do yourself a favor and order a dozen of the little spacers that go inside the hole in the blade that the mounting bolt slips into, because... even if you find the blades that you WILL toss, you will not find the little spacers.