Grading Blade Removal problems 914 MMM

MikePA · Apr 19, 2003

Broke down & Bought an impact wrench... 
Air or electric? What kind? If air, what kind of compressor do you have?

hazmat · Apr 20, 2003

Air Cambell Hausfeld model PL250298AV $75 at walmart. 425 ft-pounds of torque.

I have a craftsman compressor "6 HP" 30 gallon vertical

Don't worry about matching the air requirements on an impact wrench since it is used intermitantly & the compressor will keep up. A sander or a paint gun is another story...

Bird · Apr 20, 2003

I haven't seen one of those impacts; looks like an IR231 clone, and rated the same on power; ought to be a pretty good one. Does it have a grease fitting in the middle of the rear end? Should look like a dimple with a tiny ball bearing in the middle; not a grease fitting like your tractor has.

hazmat · Apr 20, 2003

No grease fitting on the rear end. It has a setscrew on the side just above the trigger you remove to oil the impact mechanism.

I did take your advice & purchase one with >400 ft-lbs. The Ingersolls are around $200 for that power. My dad has a 225 ft-lb craftsman. I've been able to loosten nuts with an 18" breaker bar that that thing wouldn't budge.

So far the wrench has removed the 4 snow tires on the wifes car. Just in time, they are now forcasting snow on Wednesday /forums/images/graemlins/crazy.gif. Also removed 4 tractor tires, so I can demo the turfs. Hasn't skipped a beat yet. I figure I'll only use it a few times a year, so I didn't need to buy the "industrial" strength brand. I might have been sleeping on the couch if I paid $200 to loosten 1 nut. /forums/images/graemlins/tongue.gif

Spencer · Apr 21, 2003

( So far the wrench has removed the 4 snow tires on the wifes car. )

hazmat, you probably have already heard this but in case you or someone else reading this hasn't, then here goes. It's fine to loosen lugnuts with an impact wrench when changing automotive tires but it is best to tighten them by hand. Impact wrenches can warp some rims if the lug nuts are tightened too much, or so I have read.

Anonymous Poster · Apr 21, 2003

Just a quick question... did the bolts come off clockwise or counter clockwise? I need to take mine off... for the first time.

hazmat · Apr 21, 2003

CCW. They are the normal "righty tighty, lefty loosey". They even state that they are right hand threads in the manual. Nice and reassuring. I can remember trying to take a pedal off a bicycle, I kept cranking on it with everything I had, just to find out it was a left hand thread. /forums/images/graemlins/crazy.gif

hazmat · Apr 21, 2003

Spence, yup I know. Notice my choice of words "remove" the wheels. Always appreciate a reminder, you read right, you can warp rims, especially aluminum ones. Someday I'll get a nice ratcheting torque wrench to use, the bar type I have, is a little cumbersome.

cdcole · Jun 20, 2003

I had the same issue today. Don't matter if you put a wrench on the nut - it will simply unscrew. Please tell me why the impact wrench worked when I know for a fact if you hold the nut on top of the spindle - if the blade bolt is tighter than the nut - the spindle will spin out of the nut (with the bolt holding the blade still tight in the spindle). Opinion - need one to be left handed threads. Finally today - I said screw it - sharpened that one while still on the mower. Pain in the xxx. /forums/images/graemlins/frown.gif

Please - someone give me some detail on the above.

thx

hazmat · Jun 23, 2003

Please tell me why the impact wrench worked when I know for a fact if you hold the nut on top of the spindle - if the blade bolt is tighter than the nut - the spindle will spin out of the nut (with the bolt holding the blade still tight in the spindle) 

The physics behind why the impact wrench works is complicated - I'm a mechanical engineer & I have trouble getting a handle on it.

In the steady state - IE you are pushing with all your might with a breaker bar on the blade side & trying to counteract it with a wrench on the spindle side, if the blade side is tighter than the spindle you WILL loosten the spindle before the blade. This is why new holland wants you to use the spanner wrench - it holds the spindle shaft - not the nut.

The impact wrench gives very short bursts of force (called impacts in the phsyics world as well). It is now a dynamic (moving) problem. Each impact starts to turn the blade side of the spindle assembly, but the duration is so short that it doesn't get to affect the spindle side.

The physics behind it is that the spindle assembly has some finite stiffness. Ie it is a very stiff spring. You can rotate one side slightly while the other side is still stationary. If both the blade side and spindle side start at 12 O'clock, you may have to rotate the blade side to 11 O'clock before the spindle side moves. The impact of the impact wrench is so short that it never gets to 11 O'clock.

Clear as mud eh? Print this out & tell your wife that you need an impact wrench so you can further your knowledge of physics. /forums/images/graemlins/tongue.gif