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Replacing the mandrel on a Craftsman 42-inch deck lawnmower

TomK's Avatar

Join Date: May 2006
Posts: 7

08-17-08, 09:39 AM   #1  
Replacing the mandrel on a Craftsman 42-inch deck lawnmower

I have a Craftsman 42-inch deck lawnmower, and need to replace the mandrel and central shaft on one side. I bought two, and so am actually going to replace both...

To get the old ones off the deck, I need to remove their pulleys. To remove the pulleys, I need to remove the top nuts on the mandrel.

And here my troubles begin...

Because when I put my ratchet on the top nut and turn it, the whole central shaft turns. I have nothing to brace against! If I try and put a ratchet on the blade-attachment nut on the bottom, well, it just loosens first.

How do I get this top nut off? I can't find anything to brace against to halt the central core's turning. My father-in-law and I are puzzling over this, and utterly stymied.

Thanks in advance,
- Tom

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rogerflies's Avatar

Join Date: Jun 2008
Posts: 150

08-17-08, 12:51 PM   #2  
Can you put the blade back on, and use it to stop the mandrel from turning?

GlenM's Avatar

Join Date: Nov 2007
Posts: 432

08-17-08, 06:59 PM   #3  
An air impact tool getsum off real quick.

mattnoell's Avatar

Join Date: Aug 2008
Posts: 1

08-26-08, 05:17 PM   #4  
removing top mandrel shaft bolt

leave the blade attached.
use a tie down strap around the pulley to something stationary on the deck, the kind with the ratcheting action.
once you get some really good tension on the top bolt then you can back it up with the blade bolt.
if you have a rusted bolt and nut you can use a mapp gas torch, propane doesn't seem to get hot enough, heat the bolt and nut up pretty good and then spray water on it from a spray bottle.
this will break the rust bonds better than any chemical. It's called thermal shock.
good luck and may the lord be on your side.

matthew noell
Whitewright and Daingerfield Texas
[email protected]

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