As can be seen in the following photos, once the plastic shield is removed to expose the nut, the lock nut is deeply recessed into the top mount and it’s virtually impossible to get a spanner on this nut and hold the shock absorber piston arm still at the same time given how tight the lock nut is.
The main problem is that Mazda put this lock nut on extremely tight and you can’t stop the shock absorber ram from spinning whilst you get a socket on the nut.
A ring spanner is also difficult to fit into the recess in the mount. If you were to hold the ram with mole grips low down, the ram would be scored and the 1st time the shock was compressed, the seal would be damaged and the shock absorber destroyed.
Luckily, there is an old trick to get this nut off without causing any damage. The strut can be stripped either on or off the car but it's easier to work on it off the car.
BEFORE YOU DO ANYTHING ELSE, GET SOME PROPER SPRING COMPRESSORS AND TAKE THE TENSION OFF THE SPRING
you need to grip the ram to stop it spinning whilst undoing the nut...
under no circumstances should you grip the ram here...
if you do, you will destroy the strut...
here's the trick...
Get a large flat blade screwdriver and prise the rubber dust shield and bump stop down the ram to expose the top part of the ram.
This top part can be gripped securely with a pair of mole grips as any damage this high up will not pass through the seal and damage it
Once the mole grips have a solid grip on the ram, undo the lock nut with an impact gun.
The nut will come off easily with this setup and the mount, spring seat, spring and rubber dust shield can then be removed...
then refurbed...
and put back together.... again, grip the top of the ram and use the impact gun to tighten the nut...
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