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2004 Forester XS (SOHC EJ251)

 

Is my crank pulley shot? If so, how/why?

 

Short story: I can hold the outer edge of the crank pulley in place, but the inner portion spins.

 

Long Story: Today I was trying to remove my crank pulley in order to replace my timing belt. I have a chain tool similar to this one that I use to hold the pulley in place. With the outer edge of the pulley held in place, I began loosening the bolt that holds the pulley to the crankshaft. This is where the problems start. The outer portion of the pulley stays still, while the inner portion turns with the bolt. Just to double check what was happening, I pulled the driver's side timing cover and confirmed that I can turn the crankshaft while the outer edge of the pulley is held perfectly still.

 

Longer Story: The other day My car suddenly started idling really rough while I was stopped at a light. It stalled itself out, but I got started and pulled to the side of the road. Running terribly and lacking in power BIG time. I popped the hood and saw that my A/C belt was shredded. The nut that holds the idler pulley to the bracket of the A/C belt tensioner was GONE. The belt forced the pulley into the timing cover, which cut a big hole in the cover and shredded the A/C belt. I suspect that the pulley also pushed on the timing belt and caused it to jump time which gave me the rough running and low power. I basically idled it the 2 blocks home and started to tear it down. That's when I discovered this odd behavior from the crank pulley.

 

Any advice?

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not uncommon but, usually older cars.

 

there are replacements available, OEM can be pricey - or get a lightweight pulley like Perrin makes.

 

 

2015_sti_perrin_crank_pulley-9_3.jpg

Edited by 1 Lucky Texan

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I was considering putting in a lightweight pulley anyways, but decided to save the money since the budget is a little tight at the moment. If my pulley is toasted though, I'll certainly replace with a Perrin, Grimmspeed, etc.

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when I shopped it, new OEM was more expensive.

They definitely are. I just found a lightly used Perrin model locally for $50. Can't beat that!

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you may need to get creative on removing your old one - using the 2 holes in the middle part. If they aren't threaded, thread them and put xtra long bolts in to put a bar between.

 

you can find posts, pics and maybe videos of home-made tools for that.

 

I'm just going to put a breaker bar on the bolt, brace it against the floor, and blip the starter.

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Yeah the rubber dampener section fails and lets the outer section of the pulley spin. Might be what caused the problem with the AC belt if the belt slipped off and got hung up on the idler pulley. Or vice verse, the damaged idler might have put stress on the crank pulley and caused it to fail. It's a common failure when the crank pulley gets old enough. Happens frequently enough that it's almost considered a maintenance item.

Edited by Fairtax4me

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I found a Perrin pulley locally for $50. With the heavy oversized tires on my car, a little less rotating weight will probably be helpful. I'm hoping it might help my throttle response and eliminate the need to slip the clutch so much on uphill starts.

 

If nothing else, it'll be pretty  :lol:

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They don't really do anything noticeable. Just look pretty and are cheaper than the OE. 

 

Lightweight flywheel make a difference but it's because of not only the weight reduction, but also where that weight is removed with respect to distance from axis of rotation. 

 

GD

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They don't really do anything noticeable. Just look pretty and are cheaper than the OE. 

 

Lightweight flywheel make a difference but it's because of not only the weight reduction, but also where that weight is removed with respect to distance from axis of rotation. 

 

GD

 

I expect little to no difference. Maybe I'll get some placebo effect! Who cares if it actually is better if it feels better?  :rolleyes:

 

No matter what, it will be in one piece, and that's better than what I've got now!

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I found a Perrin pulley locally for $50. With the heavy oversized tires on my car, a little less rotating weight will probably be helpful. I'm hoping it might help my throttle response and eliminate the need to slip the clutch so much on uphill starts.

 

If nothing else, it'll be pretty  :lol:

 

for big tires starting uphill you would want the heavier flywheel/dampner weight so that you can just pop the clutch out and not slip it.  with lighter flywheel you are more likely to stall and need to slip clutch.

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for big tires starting uphill you would want the heavier flywheel/dampner weight so that you can just pop the clutch out and not slip it.  with lighter flywheel you are more likely to stall and need to slip clutch.

 

That makes perfect sense. Now I feel silly.

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I expect little to no difference. Maybe I'll get some placebo effect! Who cares if it actually is better

I consider them an upgrade since they can’t fail, removes an uneccessary SPF (single point of failure).

 

Ive done tons of Laplace transform calculations vibration analysis, blah blah blah so I’m not asking about “theory” or the obvious “why” - but why do people get away with running without them all the time? Do any manufacturers use single piece pulleys?

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Are you saying the inner rubber ring on the harmonic balancer dry rotted separating the inner core from the outter ring? If so that is common. Happened to me. Got a new one off eBay. 10 years latter no issue

Edited by msmithmmx

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Are you saying the inner rubber ring on the harmonic balancer dry rotted separating the inner core from the outter ring? If so that is common. Happened to me. Got a new one off eBay. 10 years latter no issue

 

It seems that that is what happened. It is all still in one piece, so I think I caught it early. It looks like it is intact. but I can hold the outer ring in place and turn the inner core inside of it.

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Get a new pulley of eBay. Do you think your timing belt jumped? If so that is a bigger issue.

 

he's already got another pulley to fit it. 

 

It seems that that is what happened. It is all still in one piece, so I think I caught it early. It looks like it is intact. but I can hold the outer ring in place and turn the inner core inside of it.

 

tack weld it or set some self tapping sheet metal screws (i would just weld it, but i've seen that done before) between the two and you can keep it as a spare. 

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Get a new pulley of eBay. Do you think your timing belt jumped? If so that is a bigger issue.

 Definitely jumped time. The passenger side cam pulley was off by like 3 teeth. I lined it all back up and started the engine and all seems to be fine. I'd say it was a seriously close call!

 

New timing kit, timing covers, A/C tensioner, accessory belts, and crank pulley are going on this weekend.

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Timing kit went on no problem. All is well with the engine now. I do still need a new tensioner for the A/C belt, though.

 

Some interesting bad news is that my radiator is basically just being held in by force of habit. The mounting points for the bottom of the radiator are completely rotted off the rad support. I'll have to come up with a clever solution to keep it reasonably in place.

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