MOABmiata

My 94 has some pulley wobble. I've taken everything apart, and there is no wear on the crank/key/keyway. I don't know how to tell if my dampener in my main pulley is bad. I put everything back together and torqued them to spec and still have wobble.

The only wear I saw on the pulley boss was where it contacts the crank, on the opposite side of the keyway there was a slight ridge. How tight should the pulley boss fit to the crank? I can take mine off and put it on with ease. Should the pulley boss have no slop on the crank when its not tightened down? Considering everything on the inside looks okay (nothing obviously chewed up like on the SNCs), is the wobble still something I should be worried about? I'm guessing it is.

shuiend

iTrader: (24)

How tight was your crank pulley bolt when you first removed it to check everything? I had an issue where mine loosened enough over the course of 25k miles that the slot in the crank pulley boss widened just enough to cause the front pulley to wobble. I replaced that part with another used one and the wobble went away.

MOABmiata

It was pretty tight. Not tight enough to be a bitch to get off, but as tight or likely tighter than the 122ft/lbs. Definitely not loose. It was also really dirty on the in the threads when I took it off. Could the crank pulley bolt be out of spec enough to cause a wobble? I cleaned it up when I put it back together.

dieselmiata

iTrader: (3)

If you are sure the keyways are in good shape, the rubber inside the balancer is likely shot. This happened to me last year on my 1.8. The only solution is to get a new harmonic balancer.

Pen2_the_penguin

iTrader: (4)

I know, seems like a dumb question but; when tightened down, and with no belts, can you wiggle it by hand or lightly by a breaker bar?

shuiend

iTrader: (24)

It is common practice to replace the crank pulley bolt and the key when doing a timing belt. So I would just buy new ones, which you can pick up rather cheaply from Finish Line Performance.

It is the keyway on both the crank pulley boss that you want to make sure is perfectly straight. If you put in the key and can move it around any start to seriously look and see if it is perfectly straight.

MOABmiata

First off, thanks guys. You've been infinitely more help than m.net already.

Is there any way to check the quality of the rubber with it off the car? To be honest, I can't even tell where the rubber is.

No. The pulley boss has some wiggle to it when the bolt isn't tight, but once its tightened up there is no slop.

I don't have any problems with replacing the bolt really, so I'll look into that. I can try to see if the key is straight. Until now though I hadn't taken the timing sprocket off (don't want to deal with timing). I don't see any obvious wear and doesn't wiggle in the crank keyway, so I assumed it was fine.

Pen2_the_penguin

iTrader: (4)

+1 to just a bad harmonic balancer

dieselmiata

iTrader: (3)

There's no real way to check except for process of elimination. If the boss sits flat with no slop when the bolt is tight, and the keyways are in good shape, than the only thing left is the rubber. The balancer is actually 2 pieces held together by a rubber dampener. Over time it hardens and warps a bit, allowing the outer ring to wobble a bit.

When I get home i'll check my box o' parts. I think I may have an extra one for a 1.8l.

poobs

iTrader: (1)

Likely

Preluding

iTrader: (10)

I found the same thing on my car last fall, everything was tight and crank wasn't worn but it still wobbled. Being the lazy guy I am, I ignored after that.

On the way back from an 8hr trip, the vibration ended up getting the best of the water pump pulley and that snapped off. Tow truck home.

Got a good shape used pulley off of here and installed it (and replaced broken WP Pulley), no more shake.

MOABmiata

The general consensus is I'm in the market for a new pulley then. Thats okay, my only issue is that I need to drive the car back to college in a couple days (400 miles each way). I doubt I could get a new pulley in time, but I could replace it next time I'm at home. Considering the car has had this issue since I bought it, and put 12,000 miles on since with little visable wear, am I crazy for attempting to put another 1000 miles or so on it before I fix it?

Pen2_the_penguin

iTrader: (4)

might as well get a nice harmonic balancer as a replacement while you are there.

MOABmiata

No doubt, I will be on the lookout for one, but college apartment life plus street parking makes working on cars difficult.

dieselmiata

iTrader: (3)

Maybe, maybe not. It could last another 10,000 miles, it could give out next time you start the car. One thing for certain is that it won't get any better. A wobbly pulley is really bad for the crankshaft keyway and could cause some serious problems if it decides to break free. Replacing a balancer is a lot cheaper and less time consuming than a crankshaft. Rosenthal mazda can have the new one to you in a day if you wanted to pay for the shipping. Maybe a local dealership has one? It's worth a shot.

Leafy

iTrader: (1)

Your college doesnt have a motorsports/sae/ricer club that has its own garage?

MOABmiata

It does, but I doubt they want any old biology major utilizing their facilities. I'm looking into replacing it while I'm at college. Either way, if I decide to drive it I know its my own choice and I may need to pay the consequences.

One more question. My car is supercharged (I neglected to mention that so as not to feel the wrath of MT.net) and when I put just the supercharger pulley on the pulley boss without the balancer I still see some wobble. Any thoughts on why this would be?