removing bush hog blades

[gerard]

Well after many tries on my own including a propane torch (don't have acetylene) and a three foot cheater bar there was no way I could break the bolts for my 5 foot bushog which I purchased new two years ago. Had a service truck doing some work on my neighbors tractor finally get them off for me with a torch, and a bigger cheater bar. Turned out the putz's at bushog torqued the nuts down so much when tightening them they stripped the threads!!! Had to buy two new bolt setups for $16. My question (after being allowed to vent a little!!) is when I put on the new ones and using some anti seize on the threads, does tightening as much as I can with a three foot bar tighten them down enough? My air impact is only 1/2inch and good for about 375lbs torque so that's my only option.

 

[MikePA]

What does the Owner's Manual indicate the torque requirements are?

 

[gerard]

If my memory serves it indicates 975 ft lbs which doesn't seem achievable with my air wrench. Was just wondering how long ie how much leverage are people using to tighten the blades? Using a 3 foot pipe over my 3/4 inch socket drive was about the max I think the wrench can take (The shaft was flexing and if I use a longer pipe I was concerned about rounding off the nut as my large sockets are the "made in china" variety and not made of the best steel.

 

[Stonewall]

Bummer about the over torque-ing the original nuts. On my old Massey RC, the bolts have holes in them to accomodate a large cotter pin which actually keeps the bolt on. The nut has slots cut in one side to accomadate the cotter pins. I replace CPs every other blade removal so they don't fatigue too much and fail. This set up has worked for 30 years. I can't say the same for the mower deck!

 

[gerard]

Sounds like a much better system - wish bushog had gone that way!! They DO have pretty substantial lock washers on them so hopefully that should hold things on...........

 

[ScottAR]

Our bush hog has "squish nuts" (I'm not really sure of the name of these things) on the blade bolts. The bolt/pins are press fit so I don't really worry about losing one. I use a 3ft pipe wrench on a 1960's bushog socket and tap it a couple times with a 15lb hammer. Probably not really accurate but it works.

 

[normde2001]

I can't imagine anything requiring 975 pounds of torque. I would just crank it down with the impact wrench, give it another shot with the breaker bar, then maul a thread with a hammer and center punch, and it ain't goin' nowhere. The thread will repair itself the next time you loosen it.

 

[OverlyRun]

Instructions for my five foot Land Pride says to apply 450 lb of torque; my torque wrench stops at about 375. So when I put new blades on this weekend I used used the pipe on my 3/4 socket with as much shoulder as it took to get the factory installed blades off. This is about as scientific as I could get. .

The cotter pin sounds like an easy thing to design in, not sure why Land Pride and others haven't. The pan comes with one on the nut that holds it to gear box. Manual describes the "lock nut" for the blades but it seems like an ordinary nut to me. I'll be checking tightness periodically at least for a while. At three hours they haven't budged but I imagine that it would make a racket (and a lot worse) if one came off.

(Access hole for the nuts on the Land Pride works really well to hold the socket and nut while lossening/tightening. Made this a really simply task...finding blocks to put under deck while I crawled under took more time. Now if I just had longer arms I could hold the blade and bolt up underneath while I put the washer and nut on above. A lot longer arms....)
Chas

 

[Chillimau]

A torque multiplier will do the trick. I have a Land Pride and it needs 600 ft/lbs. Proto makes a nice one, 6212, output is 1200lbs with 200lbs input, 6:1 ratio so 100 lbs on the torque wrench = 600 on the nut. Only problem is one of these tools is $1,200 to 1,400 new. ebay is a good place to look. Nice ones will still bring $250 to $500 tho.

 

[ScottAR]

I think what I'm calling squish nuts are the lock nuts you describe. They look like a regular nut, but they seem to deflect a little when tightening. This squish keeps them tight.