Welcome back Patrick !
...and congratulations with your new blower.
IF IT AIN'T BLOWN IT SUCKS !
.. Had a go at it but it will take a better press than I have here in the garage to split the body!!!
P L E A S E D O N O T DO T H A T !!!!!!...if it's build the same way as my AISIN 300
and I'm pretty sure it is.
Please see this ( and scroll down ):
CLICK ...where you'll find pics of the failed 'rebuild' of my (first) blower.
First problem: you will inevitably damage the bearing during dis-assembly
and they have the most wacky of wacky dimensions and they are NOT available.
As you can see ; that problem can be worked around.
BUT
The problem, to witch I never found a solution is that there is NO WAY
you can hold the rotors in ABSOLUTELY correct position during assembly.
I thought I could, using the method shown, but it never was perfect and it
needs to be bloody PERFECT.
The smallest of smallest of the smallest out-of-true will cause them to interfere with each other.
Now IF you have them in the correct position there is no way to
avoid that the position of one of the cogwheels ( is that the phrase ?) WILL move.
As you press it in with the nut it moves because of the 'angle' of the cogs in the cogwheel.
It's a VERY strange set-up.
BOTH wheels are pressed on ( you'll need a LOT of heat . It's EXTREMELY tight )
AND one (!) has a nut.
As you tighten up the nut the wheel clings to the lobe-shaft
and as the cogs are 'angled' ...the wheel turns ( in relation to the other wheel )
and drives the shaft with it...ever so slightly....
and the set-up gets out of wack.
The blower that I rebuild for my Honda didn't have that problem cause
the cogs are straight.
I really wish I could explain it better.
If need be, send me a PM with your phone-number and I'd be happy to give you a call
and maybe explain it better.
[ EDIT: just re-checked you pics. Appears that maybe your 500 isn't build the
same way as mine, so maybe you don't have the same problem (?) ]