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MTD (Murray) 30" Rear Engine - Stubborn Blade Nut

#1

1

1saxman

Hey y'all, a newbie to this forum but not mowers. I was cleaning up/lubing my mower after its second season (light use) and planned on taking off the blade and sharpening/balancing like I do with my smaller mowers. I got out my breaker bar and a heavy-duty 15/16" socket, braced the blade and pulled - no go. Okay, did it again, but got myself in a better position and really yanked - no go. So, just wondering if these are maybe LH thread? That doesn't sound right because blade bolts are always threaded so they would tend to tighten with blade rotation rather than loosen, and I was pulling to loosen in the direction of blade rotation. Is there anything funny about these bolts before I put the jack handle on the breaker bar? I'm working on it on its wheels so I can't get my weight on it.


#2

I

ILENGINE

From your description this sounds like the MTD made Murray. The normal torque on the nut is 80-100 lb/ft, and with grass and other debris I have times that a 600 lb-ft impact won't remove it. And it is the normal right hand thread. I have a 4 foot long 3/4 drive breaker bar that I keep handle for those stubborn nuts.

Need to find a solid stop for the blade, and break out the cheater pipe.


#3

StarTech

StarTech

Or just get a very good impact a hold of it. Here I am using an Aircat 1150 with 1300 ft-lbs of reverse torque. BTW I also got a 1/2 breaker that I put a 5 ft cheater pipe and row boat off the bolts but I haven't used it since I got the Aircat.


#4

B

bertsmobile1

Not uncommon to be forced to cut the blade nut / bolt off because I can not remove it .
Like the other techs, I have a 1480 ft.lb 1/2" drive impact and the landlord has 2200 ft.lb 1" job ans still the angle grinder has to come out a 1/2 dozen time a year.
Nut are fine cause I can cook them red hot & remove while still hot but you can't do that with a bolt .
You might have to remove the blade every season to prevent this happening in future .


#5

1

1saxman

Thanks, gentlemen, I appreciate your input. I have a lift for it that I haven't assembled yet which will get the mower to an angle where I think I can brace the blade and get a foot on the bar. First, I'll soak it a few times in 'Sili-Kroil'.


#6

Hammermechanicman

Hammermechanicman

Harbor freight Earthquake 1/2" battery impact.
Satisfaction guaranteed!

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!
www.harborfreight.com www.harborfreight.com


#7

PTmowerMech

PTmowerMech

When I can't get the nuts off, I'll take the pulley off and the blade and spindle will drop out the bottom.
You may not have that option.
But with the blade and spindle out, and have more options.
Like taking it to a shop that has accessto heat, 1" impacts or other tools.


#8

1

1saxman

Hammermechanicman said:
Harbor freight Earthquake 1/2" battery impact.
Satisfaction guaranteed!

Harbor Freight Tools – Quality Tools at Discount Prices Since 1977

Harbor Freight buys their top quality tools from the same factories that supply our competitors. We cut out the middleman and pass the savings to you!
www.harborfreight.com www.harborfreight.com
Click to expand...

I've been meaning to get one of those anyway. I have air but the rechargeables are so convenient - and they can travel with you.


#9

1

1saxman

At least I found out it is a nut, which simplifies the problem. I'll hit it with Kroil and wait a day or so, then heat it with propane and do the Kroil again. Finally I'll heat it again when I'm set up to loosen it. Not red hot, and I think the blade will be enough of a heat sink to protect the bearings in the spindle. The purpose of the heat is to wick the Kroil all the way into the threads and maybe with a little expansion the nut will break loose enough for me to get that elusive first movement.


#10

1

1saxman

Got it this morning. Grass is growing like crazy with downpours lately so I had to do something. Had applied Kroil several days ago, wiped off the residue today and put the air-service 15/16 socket on the breaker bar. I had to raise the deck all the way (I run it only one notch down from the top) and still had to push it up to get that long socket on the nut. Solidly blocked the blade with a 2x4 in the discharge port, and put the heavy-duty jack handle upper half over the bar. Laying on the floor now, head to the front with a foot on the bar, and holding the front wheel to stop the mower, I laid some torque into it. I was sort of leery of breaking the tool and nothing was happening. Finally I said 'Break it' so I really gave it a maximum effort - POP! I thought I had cracked the socket but I had broken it loose! Went ahead and removed the blade and sharpened it. I don't normally use the bench grinder on a blade in good condition so I clamped it in the vise and used my favorite file - an 8" flat/round file from my Grandad's tools, probably 100 years old and still cuts the best I have seen. The rounded side is great for those curved cutting edges found on this and other blades.
Put it back on and used all the torque I could muster with just the breaker bar. I'm sure that will be good enough. I'd say I got about 95-100 lbs on it, comparing it to lug nuts with that same bar. I think it must have been on with at least 175.
Interestingly, the oil residue from the Kroil was on the flat flange of the nut as well as on the threads. That stuff really is 'The Oil That Creeps'. I don't know if I would have been able to break it loose without it.


#11

Mower King

Mower King

1saxman said:
Got it this morning. Grass is growing like crazy with downpours lately so I had to do something. Had applied Kroil several days ago, wiped off the residue today and put the air-service 15/16 socket on the breaker bar. I had to raise the deck all the way (I run it only one notch down from the top) and still had to push it up to get that long socket on the nut. Solidly blocked the blade with a 2x4 in the discharge port, and put the heavy-duty jack handle upper half over the bar. Laying on the floor now, head to the front with a foot on the bar, and holding the front wheel to stop the mower, I laid some torque into it. I was sort of leery of breaking the tool and nothing was happening. Finally I said 'Break it' so I really gave it a maximum effort - POP! I thought I had cracked the socket but I had broken it loose! Went ahead and removed the blade and sharpened it. I don't normally use the bench grinder on a blade in good condition so I clamped it in the vise and used my favorite file - an 8" flat/round file from my Grandad's tools, probably 100 years old and still cuts the best I have seen. The rounded side is great for those curved cutting edges found on this and other blades.
Put it back on and used all the torque I could muster with just the breaker bar. I'm sure that will be good enough. I'd say I got about 95-100 lbs on it, comparing it to lug nuts with that same bar. I think it must have been on with at least 175.
Interestingly, the oil residue from the Kroil was on the flat flange of the nut as well as on the threads. That stuff really is 'The Oil That Creeps'. I don't know if I would have been able to break it loose without it.
Click to expand...
I have not seen a blade nut or bolt that I couldn't get off ANY mower In my 17 yrs at the mow'in house with my Matco 1/2" air impact.....not because the Matco is crazy stout (which it is though) but, because all I did was disassemble cars & trucks for 25 yrs in an Auto Salvage.....I figured out how to get the toughest bolts out, there is a technic to the madness!


#12

B

bertsmobile1

FWIW
The service van has 8' length of 2x4 hollow steel tube, a 3/4" 6' breaker bar and a scissor jack
When faced with an impossible bar nut/bolt the tube goes over the blade & breaker bar goes on the nut / bolt then the jack is applied till it is just lifting the deck to stop the breaker bar falling off
Even with this sort of leverage it is often a legs on the breaker to get the fastener to shift.
Now you have it off, make sure you slip the blade off regularly to prevent it overtightening.


#13

Hammermechanicman

Hammermechanicman

When i was a kid my father had a bunch of odd looking really stout wrenches with big square ends. They were striking wrenches. He used them as a mechanic working for the CCC during the depression. You hit them with a sledge hammer to loosen big bolts. Used them a couple times with a BFH.


#14

Scrubcadet10

Scrubcadet10

My uncle used to work in diesel mechanics and large equipment, (Cat Dump trucks, dozers ,draglines etc)
He said there were times on some stubborn nuts and bolts he had to use the end of a boom crane on a thick cheater bar, and use hydraulic power to turn the pipe and leverage with that pipe and long crane arm them... He told me how they set them up exactly but I can't remember..


#15

1

1saxman

It won't be a big deal next time now that I know what to do. Part of my success was due to the breaker bar with long socket being just the right height so the weight of the deck held the socket vertical as I pushed the bar with my foot. This worked because I was doing it in the garage on the concrete floor.


#16

Mower King

Mower King

Scrubcadet10 said:
My uncle used to work in diesel mechanics and large equipment, (Cat Dump trucks, dozers ,draglines etc)
He said there were times on some stubborn nuts and bolts he had to use the end of a boom crane on a thick cheater bar, and use hydraulic power to turn the pipe and leverage with that pipe and long crane arm them... He told me how they set them up exactly but I can't remember..
Click to expand...
Right, but we're talking about a simple mower blade nut...or bolt here!


#17

StarTech

StarTech

I used to use those breaker bars with extension pipes. I even had one that pickup the whole body of a large ATV off the ground trying to break free and axle nut. Now that I got a 1300 ft-lb Air Cat impact I longer need to hurt myself trying to free nuts with thread deforming locks that are torqued to 300 fl-lbs. I have ran into anything that is intentionly torque over 300 fl-lbs yet. So far I only snapped a few extensions and not busted any sockets.


#18

Hammermechanicman

Hammermechanicman

StarTech said:
I used to use those breaker bars with extension pipes. I even had one that pickup the whole body of a large ATV off the ground trying to break free and axle nut. Now that I got a 1300 ft-lb Air Cat impact I longer need to hurt myself trying to free nuts with thread deforming locks that are torqued to 300 fl-lbs. I have ran into anything that is intentionly torque over 300 fl-lbs yet. So far I only snapped a few extensions and not busted any sockets.
Click to expand...
Air tools are your friend.
We need a show us your air tools thread.


#19

B

bertsmobile1

I used to deliver stuff to a local railway workshop.
One day all of the 24V ( long time ago ) impacts that I had been delivering were in a skip bin with reo welded over the top to prevent pilfering .
I asked the warehouse manager about it and apparently they had to go back to air as several railway linesmen had broken their wrists using these guns ( 1" drive ) and fu=inally, one had tossed an electrician off the top of the workshop carrige across 3 tracks and over the bridge wall so OH&S banned the battery tools and made them go back to air


#20

PTmowerMech

PTmowerMech

A couple of days ago, this guy needed someone to take off one nut/bolt from a 5th wheel hook up he was selling. I went all the way up to the 3/4" air impact and it still wouldn't budge. So I cut it off with the cutting wheel. After soaking it in something all night, the next day, I had the bolt on the vice with a breakover and it still wouldn't budge.


#21

StarTech

StarTech

PTmowerMech said:
A couple of days ago, this guy needed someone to take off one nut/bolt from a 5th wheel hook up he was selling. I went all the way up to the 3/4" air impact and it still wouldn't budge. So I cut it off with the cutting wheel. After soaking it in something all night, the next day, I had the bolt on the vice with a breakover and it still wouldn't budge.
Click to expand...
Here is some good questions about your setup. What size and length of the air lines plus also are you using hi flow couplers and adapters? When I first got my Air Cat it wouldn't even remove a nut tighten to only 50 ft-lbs. I installed a pressure gauge at the impact and found that the line pressure was dropping to less than 20 psi even when the standing pressure was 125 psi. At the time I had M style couplers and adapters installed in the line with one at the compressor so I move it out the way when I need access to it for repairs. Once I upgrade to V style high flow adapters and couplers the I regain nearly full pressure at the impact even on a 100 ft run of 3/8 air line.

So if your line pressure at the impact drops a lot even a 3/4 impact will not work at it best power if can't the pressure and CFM it needs.

The darn Campbell Hausfeld impact never worked right that I got from Wal-mart so I just gave it away.


#22

Scrubcadet10

Scrubcadet10

mower king said:
Right, but we're talking about a simple mower blade nut...or bolt here!
Click to expand...
Hey, a last resort is a last resort :ROFLMAO:


#23

Hammermechanicman

Hammermechanicman

1597161474184.jpg1597161474467.jpg
Like star says. Couplers make a huge difference. 150PSI doesn't hurt either. I backed it of from 175 because it was blowing seals out of tools.


#24

Mower King

Mower King

Everyone has all these BIG OLE 1/2 " 3/4" air impact stories.....your air impact is only as stout as the Air PSI you put through it!
Looks like HammerM has got some PSI.


#25

PTmowerMech

PTmowerMech

mower king said:
Everyone has all these BIG OLE 1/2 " 3/4" air impact stories.....your air impact is only as stout as the Air PSI you put through it!
Looks like HammerM has got some PSI.
Click to expand...


Considering his "hammer" name, I'd say he's cheating. lol


#26

Hammermechanicman

Hammermechanicman

I don't cheat. I just have a different interpetation of the rules. ??


#27

Scrubcadet10

Scrubcadet10

Hammermechanicman said:
I don't cheat. I just have a different interpetation of the rules. ??
Click to expand...
BullPaper??
?? ??


#28

Hammermechanicman

Hammermechanicman

Scrubcadet10 said:
BullPaper??
?? ??
Click to expand...
Don't have the poop emoji on the phone


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