Issues with taking blades off

[chadd]

I recently purchased a mz magnum 54 and put on mulch blades. When taking off the other blades the spindle and belt started spinning even though I had the blades blocked. I had to use an impact wrench to get them off. Now I'm having the same issue putting them on. I can't get them tight at all due to the spindle and belt spinning. Has anyone else has this happen? Any help is appreciated, thank you.

 

[StarTech]

If you read the owners manual you will find the following but of course it probably got put in File 13.

 

[chadd]

Ok, thanks. I took them off and put them on before with just blocking them and the spindle didn't turn. Thanks again.

 

[StarTech]

Yes normally I just can do the blocking here too but I had two Gravely ZTRs here where the outer blades could be torque without holding the spindle pulley side but the center spindles had to be held at the pulley to torque to 130 ft/lbs. At first I thought I had stripped out the threads.