Blade bolts to tight

[KER]

What does this have to do with my post ?

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wrench.

s

 

[lbrac]

Air pressure makes all the difference. And if you have a variable force impact make sure it's set on high. Also:

Please confirm MW article on Penetrating Oil - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

Some thoughts on penetrants for disassembly.
And when you reassemble, a dab of NeverSeize on the threads works wonders for the next disassembly. Some may say its dangerous but the majority of the clamping friction force is in the bolt head face and blade contact area....that and there is a lock washer involved, too.

I've found Kroil penetrant to be better than most for rusted bolts/nuts that have become one with the threads. It might take a while for the Kroil to seep into the threads. As a last resort, short of cutting the bolt off, a torch or heat gun judicially applied to the end of the blade shaft where the bolt enters, and on the bolt head might help, but be careful not to heat other areas that could catch fire. The heat could cause the bolt to lengthen slightly and the inside diameter of the shaft to expand enough to help removal. Applying penetrant while the bolt is warm can also improve penetration. A cycle of tightening slightly, just a few hits with the impact wrench, followed by aggressive loosening can sometimes help break corrosion. Anti-seize is also a good recommendation to reduce corrosion.

You probably already are aware of the bolt thread direction for your mower, but I once had a finishing mower used on a tractor that had left-hand threaded bolts for the blades. Only one bolt sheared off before I realized the threads were left-hand.

 

[STEVES]

View attachment 60031

Pretty well set for eztractors some are from the 1930's

I used to use those till I found these, they don't dig down & expand tightening against hole.

 

[BTBO]

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wrench.

If and when you remove the bolts, re-install them using an anti seize compound on the threads. Guaranteed to never have trouble removing them again. Keep in mind that when the threads are lubed that the torque value will be less. I replaced the standard bolts with grade 8.

 

[rustycat]

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wrench.

You will probably have to put some heat to fitting. When you do get it apart put antiseaze on the threads.

 

[Tommy Mckeown]

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wrench.

I'm guessing you tried turning in the other direction. I've seen a lot of left hand thread bolts on mower blades.

 

[slydog]

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wre

I have a mz42 great mower but the blade bolts are really difficult to remove for sharpening even with impact wrench.

I've had a Turf Tiger since 2006. Never had a problem using 1/2" drive Ingersol air pressure 90 - 110 psi. Neighbor brought his over for grease and sharpening, and spindle/blade nuts were same problem you're having. I have a Scag manuf blade lock I applied and used a long 1/2" breaker bar with a pipe to extend the handle. Nothing is ever not removable. You can apply too much torque to the nuts if your not familiar with an impact gun. Try using a torque wrench tightening to the manuf specified torque, then remove with a regular bar and socket. Many owners over tighten their blade bolts without realizing it. The nuts will never loosen at specified torque.

 

[Hammermechanicman]

We got into the problems with the planet by "getting with it " and buying way too much that we did not need just to be "on trend" or fashionable .
Having just gone through my third flood in 3 months I have no intention of adding to the problem by tossing away perfectly good air tools in favour of highly polluting battery tools.
I need a compressor to inflate tyres , run the plenishing hammer, the air chisel & spray booth so using it to power the impact is the RIGHT thing to do by humanity and it does not hurt my waller either
Being set up for air I will remain with air & corded power tools as I have more of them than I actually need , many of which I got cheap because people were tossing out perfectly good corded 1/2" , 5/8 " & SD drills in order to be "with it "
If setting up from scratch I may have gone battery but having been in recycling and done chemistry I really do not want to be part of destroying the little of the planet we have left .
Battery tools are convienent & like all lazy things substantially worse for the planet , they are not clean , green & environmentally good they are filthy but they shift the pollution & environmental degration elsewhere so of course as it is not in our backyard it doesn't exist, till of course it does and we end up with a flood every month , tornados where there has never been any recoded before cyclones that exceed all known ones by orders of magnitude , show falls & / or hail so heavy that it caves in roofs .

Call me the environmentally unfriendly guy but i like my air and battery tools. After seeing how much large corporations waste and put in landfills i don't feel too bad.

 

[Hammermechanicman]

I've had a Turf Tiger since 2006. Never had a problem using 1/2" drive Ingersol air pressure 90 - 110 psi. Neighbor brought his over for grease and sharpening, and spindle/blade nuts were same problem you're having. I have a Scag manuf blade lock I applied and used a long 1/2" breaker bar with a pipe to extend the handle. Nothing is ever not removable. You can apply too much torque to the nuts if your not familiar with an impact gun. Try using a torque wrench tightening to the manuf specified torque, then remove with a regular bar and socket. Many owners over tighten their blade bolts with realizing it. The nuts will never loosen at specified torque.

Zip em down till the threads strip and then back off a quarter turn. Works every time.

 

[slydog]

The impacts are for installing spark plugs, not blades.

I use the impact also for carb studs. head bolts, and valve cover bolts. I'd use it for rod bearings, but I can't find one small enough to fit in the crank case.