Crankshaft Pulley Shaking

[Roamer]

I am new to this forum however, I am not new to Subaru ownership. I have owned over the past 10 years of driving 6 Subarus for either myself or my family. Currently on my 1997 SUbaru Outback wagon I am experiencing a shaking crankshaft pulley. Last week I was driving and all the warning lights on the dash lit up, my belt had fallen off so I drove to the nearest mechanic and he installed a new belt. Now a couple of days later I was just checking my tranny oil and noticed that the crankshaft pulley shakes ALOT. To the point that when the care is idling it feels rough. But when I reved up the engine I noticed that the shaking lessens or goes away. Now I am not a mechanic by any means so excuse me for my ignorance, but can anyone direct me on what the issue could be here?

 

I took it to my local mechanic whom I do trust but I doubt his ability to work on subarus, but this has never been an issue before because aside from regular maintenance I never needed a "Subaru know it all Mechanic". He told me that I need a new pulley, of course this seems to be the obvious answer but I am perplexed on why my pulley would shake to begin with? I did have this mechanic change my timing belt 5 months ago so I am assuming that he had to take this pulley off to get to the timing belt.

 

So my question is could he have wrecklessly done something wrong in reinstalling the pulley? It just makes no sense to me how a pulley can need replacement or would start shaking out of the blue? I am contemplating taking it into a Subaru dealership however this car has over 165K miles on it and I do not want to be bothered with a huge bill. But any suggestions from you professional folks would be appreciated. For instance if I buy the pulley can I just have my mechanic install it? Is there some special Subaru knowledge or trick that he needs to know before installing it?

[svxpert]

<<So my question is could he have wrecklessly done something wrong in reinstalling the pulley?>>

 

 

yeah, he didn;t torque it down properly and it worked itself loose. i've seen this alot of times. mostly because people don't have the proper tools for the job. you better have this looked at soon before it digs into your crankshaft, thwn your really screwed!

[frag]

I think the proper torque is aroud 120 ft-lbs and due to an error in one edition of the FSM, a lot of people undertorque the crank pulley bolt.

Before retorquing to proper values, you should inspect the crank shaft, key and key way to see if it has not been damaged. If damaged, other people here who had the same experience will give you more advice.

****For the time being dont drive the car with the pulley wobbling.

[Lawsonmh15]

That sucks man. As you may have read, I have recently fallen victim to the Crank Pulley demons. It's more than likely not that the mechanic torqued it down improperly... Well possible, but not likely.

 

You said you took it to a mechanic when all your warning lights came on, i.e. battery and brake. You're pulley's busted more than likely. There is a disc on the front of the pulley that the bolt snugs against. All that holds that disc there is glue. Once the glue dies, you no longer have a solid mechanical bond, so each time you have an abrupt change in RPM you will be able to duplicate the loss of belts, the need for a new pulley, and a possible re-keying of your crank shaft.

 

STOP DRIVING IT. Tow it to a shop and have them take care of it. Don't risk screwing up your crankshaft.