"thejustache" (thejustache)
01/22/2018 at 13:55 • Filed to: None
1
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"thejustache" (thejustache)
01/22/2018 at 13:55 • Filed to: None | 1
| 6 |
I love my Subaru (so much so that I signed up for their Subaru Ambassador program several months ago on a whim and recently found out I got in. Free swag incoming!). Like any good relationship though there are sometimes things that come up along the way and require some time and effort to make right. I suppose also when you’re running about 65 pound-feet of torque over stock on a car with almost 150k miles things can happen. This was a new one for me though and taught me a few things!
Basically - The OEM two piece crank pulley separated and the outer piece ate right through the plastic timing belt cover before I caught it. I should have known something was up when it threw the belt to the AC compressor a few weeks ago, but since it was low single digit temperatures for basically that entire time I didn’t bother to dig deeper and kept driving it. I finally investigated when I noticed it getting loud outside the car on startup... Inside you still couldn’t hear it, but my exhaust is pretty loud as well so that didn’t help.
Once I looked at it this weekend it was immediately obvious the remaining belt was only half on the pulley, and I saw plastic shavings everywhere. I pulled the belt and the outer half of the crank pulley just came off with it. I didn’t even know it was a 2 piece, but the forums now tell me they are and I’m not even close to the first person this has happened to. Doh!
Now I’ve got a new timing belt cover and a Grimmspeed lightweight 1 piece pulley coming my way. I’m really hoping the timing belt didn’t get nicked in the process, because if it did it’s going to need to be replaced. We’re closing on a house in 2 weeks and I don’t need to give my wife any reasons to hate my car! My surface assessment is the belt was narrowly spared and I just need to replace the cover and the pulley, but we’ll see once I pull the cover.
Anyone else run a one piece pulley? I know there has been some debate about problems caused by removing the rubber dampening layer, but given that the rubber is what caused mine to fail I don’t think I want to go back to OEM! We’ll see, and I’m optimistic the light weight model might slightly improve things for rev matching shifts.
crowmolly
> thejustache
01/22/2018 at 14:04 |
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Does it also function as a harmonic damper? If so I’d just make sure that functionality is retained in the replacement part.
jimz
> crowmolly
01/22/2018 at 14:17 |
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yeah, this. that rubber-mass system is usually meant to damp harmonic vibrations in the crankshaft, which helps prevent crankshaft fracture.
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crowmolly
> jimz
01/22/2018 at 14:22 |
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I looked it up and found this:
Important:
Based on our analysis, 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.
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thejustache
> crowmolly
01/22/2018 at 14:29 |
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Well that is the concern. I’ve seen a statement from Subaru that their EJ engines don’t have a harmonic dampener. I’d guess then that the rubber layer was just for sound? I’ve also seen people saying that the OEM crank pulley is indeed the dampener. There are plenty of people on the forums running the one piece pulleys with no issues over time, and then some others saying they did cause problems. It’s a little unclear, but I do generally trust parts by Grimmspeed so hoping for the best. I’ll probably pick my mechanic’s brain before leaving it on there long term, but the 1 piece was $125 with prime shipping on Amazon and the OEM was well over $150 from the dealer and would have taken a couple days just to get in stock. I just need to get my car back driving again!
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jimz
> crowmolly
01/22/2018 at 14:32 |
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it might not actually need one; IIRC it depends on the particular engine.
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crowmolly
> thejustache
01/22/2018 at 14:33 |
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I checked on Grimmspeeds website and they address the issue. If Subie says no dampener then I’d take Grimmspeed at their word.