you tell me

tbro · Postby **tbro** » Sat Feb 28, 2015 6:34 pm

Whats wrong with this picture and why?????

or this

OK now this one

so?????

hks_kansei · Postby **hks_kansei** » Sat Feb 28, 2015 6:50 pm

I don't really get what you're asking?

they're both pulleys, both keyways look fine (as much as you can tell from the pictures anyway).

One looks like it's been dragged along concrete, or been cleaned up by someone a little heavy handed with the wire brush.

project.r.racing · Postby **project.r.racing** » Sat Feb 28, 2015 6:54 pm

a couple of small holes missing?

tbro · Postby **tbro** » Sat Feb 28, 2015 8:05 pm

Have a GOOD look at the first picture and you will notice fretting on the mating surface.
Now combine that with sh*t in the keyway and then tell me how that is all suppose to seat properly when put back together,
and that IS how it was put back together by a Mazda Specialist. The car had done 250ks since the belt was replaced and was making a "funny noise",
so I strip it down after seeing the harmonic balancer wobbling.

The second lot was off Scooter (after 15000 kms and 3 motors) after being stripped down after a slight rise in temperature (237 degrees) apparently these motors are a bit suss to heat!!!!

As Ryan knows doing the job on a 323 isn't hard but I would rather drink lots of beers than do this again, so off to the computer and the owner has ordered new bolt,
key and gear,which will be here next week.

So tell me , what causes loose crank pulleys after strip down , poor preperation resulting in the gear being held away from the crank face which starts fretting and then stuff comes loose. You have to clean everything properly and that includes all mating surfaces otherwise you will get bit in the arse and it will probably cost you a crank job. Replace key and the bolt at a mininium and tension it to specs, not AS tight as ya can.
Loose harmonic balancers has been an industry concern since Adam was a boy and every manufacture found fretting was the cause so take heed and do it properly.

Ok, end of lesson.

Caffeine · Postby **Caffeine** » Sat Feb 28, 2015 9:21 pm

Dealer did worse to mine during the 100000km service. My pulley had so much slop in it it has actually touched the cam cover.

I'm currently trying to source a replacement pulley boss. Cheapest for new is about $100US plus shipping (i.e. close to $200 AUD landed)

ralt · Postby **ralt** » Sun Mar 01, 2015 12:28 am

Hi.
Good of TBRO to bring this up. If you have a woobly pulley and decide to do the loctite fix it is important to buy a new key and trial fit it in the pulley as the key is made of tool steel and the pulley is a softer metal. If it is not a tight fit buy a new pulley. The problems you can have if the above not done is the pulley even if not correctly tightened will move in the direction of rotation when power is applied and will move back when you slow the motor eventually as the belts used on alternators etc pull the pulley back. The result is a worn keyway and you are back to square one.
Quite often as crankshafts are heat treated it puts strength on the surface of the metal but is brittle and because of this movement any high spot on the crank nose will get red hot and as the heat treating is only thin and brittle it will give way and you may find your crank may have a pit in it. It will not compromise the crankshaft.