914A throwing blades

RuT · Aug 2, 2004

Any ideas?

I have a 914A side discharge mower that keeps tossing the left side (away from chute) blade. It's done it twice this year. Either luck or symptom, it always does it when "spinning down" after I disengage the PTO. I hear this metallic chink noise and then the blades laying in the grass with all the related hardware.

Everything seems in order. I have to admit that I don't specifically torque it to a specified setting, but I did not have problems the previous 300 hours. Now, it's tossed it twice in the last 30 hours. Everything appears fine.

What do you all think?

PineRidge · Aug 2, 2004

If nothing is bent or damaged I would use a good grade of thread locker. It will keep the blade bolt tight and you can still get it out using a breaker bar when it comes time to sharpen the blade.

dass · Aug 2, 2004

My 914 had a flat washer AND a lock washer on each bolt. If yours has the same configuration, try a new lock washer. And make sure they are installed in the right order.

thcri · Aug 2, 2004

Follow the above instructions and also when shutting down instead of taking the PTO out first try slowing your tractor down gradually first. This may help you but I would sure make sure that you do have it tightened properly and make sure you have the right washers in there.

murph

hazmat · Aug 2, 2004

You might want to try & watch the spindle on the top side of the deck when you put it on. According to the manual you are supposed to use a spanner wrench to hold the spindle while you add or remove the blade.

I couldn't get one blade off - the spindle was spinning so I inquired at my dealer about the wrench. They said they've never sold one - just use an impact gun. So I did and it worked great. I also use the impact gun to put the blades on (As an engineer this makes me cringe a bit), but I set it at 1/2 power.

Someone suggested thread lock - I put anti-sieze on mine after having such trouble getting it off. Haven't lost one yet.

Boomerboy · Aug 3, 2004

RuT,

Incredible! After 307 hrs I, too, lost the left blade on my 914A side discharge mowing deck. Just as you described, the blade was lying on the ground, with all hardware, after I disengaged the PTO. This has never happen before. I remounted the blade as usual (just a socket wrench and as tight as I could make it). I am now at 335 hrs and have not lost a blade yet, but your loss after 30 hrs makes me wonder. I have never experienced it before. It is obvious why it happens at PTO disengagement (rotation and all) but what the underlying cause is I done know. The blades had about 50 hrs on them when this occurred.

So strange - must be a disturbance in the Force! /forums/images/graemlins/smirk.gif

kensfarm · Aug 4, 2004

I never lost a blade.. but I broke two belts the first summer I used mine. There is a lip that needs to be seated properly when bolting the blade back on.. I hand tighten then use a socket to finish.

PineRidge · Aug 4, 2004

I don't know if your tractor uses a PTO brake or not but when I disengage any PTO driven implement I first come down on the RPMs I then slowly disengage the PTO lever. That way my mower doesn't come to a screeching stop and I don't damage or wear out the PTO brake faster than necessary.

TC18guy · Aug 4, 2004

I lost a 914A blade at about 100 or so hours, bolted it back up and haven't had a problem with that since. Now if I could only keep the mounting pins from falling out I'd be real happy.

RuT · Aug 4, 2004

Boomerboy...must be something about the 300 hr mark and Ohio grass. /forums/images/graemlins/grin.gif Or, maybe it has something to do with just slipping the PTO out of gear at 600rpm speed instead of throttling down and then disengaging.

OH...and another thing...DON'T engage the clutch with the throttle at higher speed and the mid PTO on WHILE going up a hill. (did that make sense?) If you do...the belt tensioner spring will go from 5" to about 1' in a second. Must have been something to do with the torque of the engine and how it all kicked in. I needed to go to low range from 2 and put on the parking brake while heading up the hill. Made all the gear change and started back up and the damage was done.

FYI...my deck did not come with lock washers on each blade bolt. I have (starting on the top side) a lipped bushing, blade, flat washer and then the bolt head. I think I'll put some lock washers on next time I have them off (or they fall off) and go from there.