legacycentral bbs

Hi guys,

I noticed the biggest pulley (don't know the name) on the bottom that is connected with the alternator is wobbly.

I cannot get a small enough socket + ratchet in there to tighten it.

thoughts? Is it safe? The wobble is noticeable when car is running, I would say about a 5mm off centric wobble.

Take another look at it. Determine whether its just the outer ring that's wobbling or if the inside ring is wobbling too. It's called a harmonic balancer and it's made up of two iron rings glued together with a rubber bushing. It's supposed to reduce vibrations through the vehicle. Over time the rubber breaks down and the outer ring comes loose and it can get dislodged a bit so it wobbles but the inside ring is not going to wobble because it's bolted directly to the crank shaft.

But, if you do not torque it properly (130 ft lbs) the bolt in the crank shaft can back out and then you have a different problem. That leads to stripped out keyway in the harmonic balancer which means your pulley is toast and your key is toast too. Either way if there's wobbling you need a new one most likely and buy a new woodruff key too. Replace it with a lightweight aluminum one piece pulley to avoid this problem in the future.

When I didn't torque mine down properly it came loose and stripped the pulley keyway and the belt came off like this:







Couple videos showing how bad it got. It was shaking the whole car!








Pics of damage to pulley:

Awesome pictures to show the issue. Thanks for the reply!

I think my harmonic balancer is ok - I should be more specific.

I was referring to the big pulley UNDER the AC condenser.





Re: Balancer

How much did you end up spending replacing the bolt, key and the pulley? I might be due for a chance in the near future.

Wait, are you talking about the idler behind the timing covers? They're all the same size. If that's wobbling you need to replace that immediately. It will eventually seize up on you and your belt with skip timing and that's never good.

I bought the pulley used for about $35 shipped for WRX harmonic OEM balancer. I bought the woodruff key for like $2 from subaru at 1stsubaruparts.com and the bolt was probably a couple bucks too. The bolt didn't need to be replaced but I replaced it anyways to have nice new clean threads and clean head.

From my understanding Subaru's DO NOT have harmonic balancers.

Yes they do. Don't you see the pictures above?

You don't want to let the crank pulley get loose with the idea of fixing it later. It is possible for them to go and fully destroy the keyway and/or strip the threads out, necessitating a new crankshaft. A new engine would be less work and possibly cheaper.

My memory is fading me, it was the BIG pulley that was wobbly (the middle one).

It does not look like the harmonic balancer as mentioned above...


RE: Crank Pulley, how does one replace that? And if so, are there any aftermarket pulley's?

http://www.grimmspeed.com/catalog/produ ... cts_id=230

$129 USD 93-11 Impreza Crank Pulley

another link with video on how to replace the pulley


http://www.toronto-subaru-club.com/foru ... lease.html

kimokalihi wrote:Wait, are you talking about the idler behind the timing covers? They're all the same size. If that's wobbling you need to replace that immediately. It will eventually seize up on you and your belt with skip timing and that's never good.

I bought the pulley used for about $35 shipped for WRX harmonic OEM balancer. I bought the woodruff key for like $2 from subaru at 1stsubaruparts.com and the bolt was probably a couple bucks too. The bolt didn't need to be replaced but I replaced it anyways to have nice new clean threads and clean head.

What year WRX would fit?

comets wrote:

What year WRX would fit?

They pretty much all fit as far as I know, I have never had one off a 08+ but I know up till then the key way is the same size and are interchangable. It isn't going to give you any advantage being off a WRX other than lower miles than a first gen Legacy. They are all pretty heavy, I think the newer ones are a bit lighter IIRC.

That pic you posted is a lightweight pulley. You need to take it off and check for damage to the key slot. Thencheck to see thats its nt warped. Then if ts ok slap it back on and torque to 130. Done deal.

I stole one of your pics that shows the engine.

It seems that you took off the crank pulley and that was wobbly - for me.


Was it a pain to install? Mind you my engine is still in the car.

Alright guys, I am a bit stumped.

Do I just need to retighten the pulley as is without removing anything?

Do I need to buy a used pulley?

Do I need a new bolt and key?

What would be the cost of the wobble?

RETIGHTEN! 120 ft./lbs. at least.

I would not retighten it. Reason being, you don't know if it stripped out the keyway or not. That's very important. Take it off and inspect it for any damage and check the woodruff key on your crankshaft. Any WRX pulley fits, any EJ series engine pulley fits as far as I know.

As it turns out,

I over tightened the tensioner, and re-tightened the bolt, all set and smooth!

Eek. hopefully everything is good. I did something similar (over-tightened the tensioner), and it turns out i warped the crank sprocket slightly. Hopefully it's good because you were using the stock pulley and not an aluminum one like I was.

The wobble came back,

I played with the tensioner, seems to have NO effect on the wobble at the moment.

I will tried torquing it down with a 22mm socket, however, the wheel keeps spinning, how does one tighten the crank pulley bolt?

I use a chain wrench on the pulley with a towel to protect the grooves. You can also get a tool that threads into the holes in the front of the pulley.

I noticed the holes, I will need to find something, perhaps a special tool for it?



PS: I noticed my pulley and belt rubbing against the timing belt cover, causing it to smoke a little, I tightened the covers up a little, but I don't think is a perm solution.


Assuming the pulley is at 140 lbs or torque already, under idle, the pulley wobbles a little, but acceleration, no wobble.

The OEM crank pulley does not act as a harmonic damper found on for example traditional V8 engine dampers. The elastomer portion of the pulley helps dampen some noise from the engine accessories (ie. alternator, PS pump, and A/C compressor) but in our experience, the increase in this noise is in-perceivable.

Here is a note directly from SOA:

"Thank you for your patience as I checked with our Technical Services Department regarding your message below. They advised that the crank pulley is a pulley and nothing else. It is not used as a harmonic damper/balancer. Thanks for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us again."

Best wishes, John J. Mergen

Customer Service Department Subaru of America, Inc."

It looks just like any other harmonic balancer ive seen from other manufacturers.

Honestly I'll call BS on SOA. The stock pulley is more than just a pulley. Normally pulleys do not have a rubber portion sandwiched between an inner and outer metal portion. Even if the pulley provides minor harmonic vibration absorption, it still has a purpose.

When the WRX was introduced in the states people started replacing the stock pulley with lightweight aluminum pullies. Tuners started seeing a loss of timing advance as RPMS and load increased. Sticking an oscilloscope on the crank sensors, they saw the output from the crank sensor become noisy. Going back to the stock pulley eliminated this issue.

Retaining the stock pulley is more of a concern for higher horsepower and rpm engines, vs. a stock engine.