Mowing Finish mower disappointments

toolz_not_toyz · Apr 22, 2006

Finally used the 48" finish mower for the second time in its life (I got my PowerTrac in late November). The first time out I lost a blade. It just fell off. When I found it on the lawn it was just lying there in the grass with the bolt and washers all sitting pretty like it plopped out. I had to replace the bolt as it was stripped at the end.

So yesterday the same thing happened. The bolts that hold the blades on don't seem to penetrate very far (mine are 1" long, 3/8ths, Grade 5). Unfortunately, all I could find was the blade this time. The bolt, washers and even the reducing washer that fits in the blade are gone. Guess I'll have to phone PT next week to get some new ones.

I'm wondering if there's a bigger problem since the screw is not holding. Anyone know what the torque spec is supposed to be for the blade bolts? As soon as I tried really tightening it down (with a torque wrench set at 44lb/ft) the bolt just started to spin.

The other thing I have concluded is that this deck just doesn't do a great job on cutting grass. At least not on the fine stuff around here. The biggest problem is that I just can't lower the deck enough to get a short enough cut. I'm starting to get concerned that I may have been better off without the deck and should have used the $$$ for a lawn tractor instead. /forums/images/graemlins/mad.gif

J_J · Apr 22, 2006

How short are you trying to cut your grass. Most grass is cut around 3 in. The experts say to cut no more than a third on each cut. If it is 6 in high, first cut should be 4 in. As far as the bolts, check the depth of the threads, and if your have sufficient depth, get a longer bolt, grade 5. Did you or someone perhaps strip the threads on the bolt or the shaft? You might find those lost parts with a metal detector, or one of those 2 ft long magnets used in parking lots.

tracdoc · Apr 22, 2006

Sorry to learn of your problem. Before getting into specific grass types, it would be good to confirm that the mower blade is indeed secure on the spindle. If not, it will not spin at its designed feet/min and the result is a poor cut. It's sorta like some mowers with a shear pin--once the pin shears when you hit a rock, the blade spins freely, and won't cut the grass worth a tinker's da** until a new shear pin is installed. So that would be the 1st think I would check, and call PT regarding the torque. It may be partially stripped with the same end result---blade not tight enough on spindle.

That said, I have had exceptionaly good performance from my original 48" mower and also my current 60" unit. If your grass is very fine, like a Zoysia, or one if its sub-species such as velvet grass, you may need to us a different type of blade to achieve a good, clean cut, regardless of where the cutting height is set. You can check with PT on that, too. Perhaps a universal mulching blade, like a Gator or one of the high-lift designs which will make fine grasses stand up better to be cut, might be all that you need. Some varieties of Bermuda grass which are best cut at an inch or even less (which we had when we lived in CA) are best cut with a reel-type mower, and the PT finish mower, as good as it is, would not cut the mustard there.

I'm optimistic that once you get your blade secure to the spindle and get the right blade for your grass, you'll love the finish mower.

toolz_not_toyz · Apr 24, 2006

Thanks for the tips guys. I was wondering if maybe the blade wasn't spinning fast enough (because of the tightening issue).

JJ, "metal detector" is exactly the thought that ran through my mind as I was searching for that thing. Regarding the stripped threads, the mower's only been used twice. I did not check the blades prior to its first use (somehow assuming that PT would have assembled it correctly, heh). I think the bolts are just too short. They only penetrate by about 1/2" or less. Would a grade 8 bolt stop them from stripping?

Could be zoysia (or a hybrid) but I'm inclined to say fine fescue. It was hydroseeded last year so it's not even consistent. Meaning we have at least a couple of species growing right now in patches. But even the more dense areas weren't getting cut well. At one point I even started to thing that maybe the blades were spinning backwards since there wasn't much evident cutting going on.

It's so temperate here that our grass stays green right through winter. Ironically, it only loses its color when it goes dormant in the summer drought. People tend to cut their grass possibly down to 2". I'm happy if I could get to 3 but I will definitely need a blade that will produce better lift. Just getting to a point where the blades remain attached would be a great starting point. /forums/images/graemlins/shocked.gif

MossRoad · Apr 24, 2006

I think zoysia is planted in plugs, not seed, so I would be surprised if it was. It turns ugly brown in the winter here and feels like you are walking on a boot scraper broom. But it is tough stuff in summer, thick and dense. It spreads like the dickens, too. Some neighborhoods have banned it because of the spreading nature and the brown winter color.

funpilot · Apr 28, 2006

I have three acres of fescue. My first few attempts were pathetic and I finally posted here regarding my problems with my 60 inch deck. Turned out it was spinning backwards. Fixed that and it cuts as nice as my Simplicity except it does not pick up the grass....Just can't let it get too long.

BAGTIC · Apr 28, 2006

I have never had any problems with the 48" finish mower on my 425 even though I have used it to mow wild roses, blackberries, small junipers, and a lot of buckbrush.

Did have a problem with the rotortiller the other day. A tine fell off. When I put it back on I had seven others lose. Gotta check bolts for tightness all the time. Considering the pounding it takes in this hard rocky ground it is a wonder if took this long.

MossRoad · Apr 29, 2006

I have an old Simplicity from the 60's and is still gives a fantastic cut. The PT deck is very close in quality of cut. If it had the little rollers to make the grass nicely striped like the Simplicity, I couldn't tell the difference.

toolz_not_toyz · May 9, 2006

( I have three acres of fescue. My first few attempts were pathetic and I finally posted here regarding my problems with my 60 inch deck. Turned out it was spinning backwards. )

Funny you should mention that. I had thought about it but never checked. Then I came across another post in the archives that mentioned this as a possibility. So I will absolutely check to see if PT reversed the lines on the motor.

They did send me some new blade adapter inserts the other day (by UPS nonetheless and they sent them for--how cool is that?).

I'll have to put longer bolts in though. Hopefully something longer than 1" will hold better. I'm going to stick with Grade 5 though as I think the hub might be Grade 8.

funpilot · May 11, 2006

All I did was disconnect the hoses to the deck and cross them over. You can remove the hydraulic unit and turn it around but that was above my skill set.

toolz_not_toyz · May 18, 2006

Apparently there was a rogue assembler in the factory (he is no longer there) that made some mistakes. Hopefully, reversed motors is a problem of the past.

In other news, blades should be tightened to the hub to 60ft/lbs. The correct bolt is Grade 5, 3/8" x 1 1/4", 24 (fine thread), and you should always use a lock washer. The info is correct for at least the 48" finish mower but I imagine it is the same for the other decks.

toolz_not_toyz · May 18, 2006

Apparently there was a rogue assembler in the factory (he is no longer there) that made some mistakes. Hopefully, reversed motors is a problem of the past.

In other news, blades should be tightened to the hub to 60ft/lbs. The correct bolt is Grade 5, 3/8" x 1 1/4", 24 (fine thread), and you should always use a lock washer. The info is correct for at least the 48" finish mower but I imagine it is the same for the other decks.

funpilot · May 18, 2006

So, was your spinning backwards as well?

funpilot · May 18, 2006

So, was your spinning backwards as well?

stray · May 18, 2006

Hay guys I have really been putting this thing to use this year. It cuts moving in one direction better than the other. If I have it swung to that side I end up backing up some to smooth the cut. This thing is a real weed eating saver. With some practice you can do well down over the pond fills and around things.

stray · May 18, 2006

Hay guys I have really been putting this thing to use this year. It cuts moving in one direction better than the other. If I have it swung to that side I end up backing up some to smooth the cut. This thing is a real weed eating saver. With some practice you can do well down over the pond fills and around things.

toolz_not_toyz · May 19, 2006

( So, was your spinning backwards as well? )

Still haven't checked. But got an acknowledgement from the factory that there were some (ahem) assembly problems. I really do need to cut the grass around here but have been so busy working on several other projects...

toolz_not_toyz · May 19, 2006

( So, was your spinning backwards as well? )

Still haven't checked. But got an acknowledgement from the factory that there were some (ahem) assembly problems. I really do need to cut the grass around here but have been so busy working on several other projects...

toolz_not_toyz · May 20, 2006

Well, it just goes on and on. The hydraulic motor on the mower was connected backwards. Switched the hoses and wow, it sure cuts better when the sharp part of the blade hits the grass! /forums/images/graemlins/shocked.gif

Before I started cutting I reattached the problem blade (the one that's been falling off) with a new blade adapter, new washer, new lock washer, and a new bolt (1 1/4" this time, which I had already purchased but Terry confirmed it was the correct length--the original was only 1" and didn't penetrate very far into the hub). Then I checked the bolts on the other blades; they were also 1" bolts, and they were loose, so I replace them. It helps to have an impact wrench to do this work.

One thing I found about tightening those blades down is that you get into a problem with the hubs spinning as you go tighter. You can't really torque those bolts down unless you can get the hubs to stop spinning. On my old JD lawn tractor the blades has two little nubbies on them so that once the blade retaining bolt was tight, the blade couldn't spin; it was also easy to jam a black of wood between a blade and the deck to get them to stop spinning while you're trying to loosen or tighten them. Can't do that with the PT.

So then I was mowing and thought this is working great! And then one of the mower deck wheels fell off. /forums/images/graemlins/mad.gif Of course, the nut was long gone. Luckily I had spares (1/2", coarse thread) in the garage thanks to my ongoing automobile work...... To be honest this one was probably my fault since I had lowered the deck a few weeks ago when the cut was unsatisfactory.

So (yup, there's more) I'm mowing along and have to move to a different section so I turn the PTO off and raise the deck. Drive to the other place, lower deck, turn PTO on .... NOT ... PTO has stopped working. /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif !!!!!!!

Probably a dead solenoid I suspect. Of course, this being Saturday there is no way this is getting fixed soon.

toolz_not_toyz · May 20, 2006

Well, it just goes on and on. The hydraulic motor on the mower was connected backwards. Switched the hoses and wow, it sure cuts better when the sharp part of the blade hits the grass! /forums/images/graemlins/shocked.gif

Before I started cutting I reattached the problem blade (the one that's been falling off) with a new blade adapter, new washer, new lock washer, and a new bolt (1 1/4" this time, which I had already purchased but Terry confirmed it was the correct length--the original was only 1" and didn't penetrate very far into the hub). Then I checked the bolts on the other blades; they were also 1" bolts, and they were loose, so I replace them. It helps to have an impact wrench to do this work.

One thing I found about tightening those blades down is that you get into a problem with the hubs spinning as you go tighter. You can't really torque those bolts down unless you can get the hubs to stop spinning. On my old JD lawn tractor the blades has two little nubbies on them so that once the blade retaining bolt was tight, the blade couldn't spin; it was also easy to jam a black of wood between a blade and the deck to get them to stop spinning while you're trying to loosen or tighten them. Can't do that with the PT.

So then I was mowing and thought this is working great! And then one of the mower deck wheels fell off. /forums/images/graemlins/mad.gif Of course, the nut was long gone. Luckily I had spares (1/2", coarse thread) in the garage thanks to my ongoing automobile work...... To be honest this one was probably my fault since I had lowered the deck a few weeks ago when the cut was unsatisfactory.

So (yup, there's more) I'm mowing along and have to move to a different section so I turn the PTO off and raise the deck. Drive to the other place, lower deck, turn PTO on .... NOT ... PTO has stopped working. /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif !!!!!!!

Probably a dead solenoid I suspect. Of course, this being Saturday there is no way this is getting fixed soon.