leak at the crank shaft - light weight pulley

[greenleg88]

On a 97 Legacy L...

 

the car once had a leak at the crank shaft...

i had paid someone to fix it...

and now i intend on putting a light weight pulley on the car to reduce strain...

 

my friend had suggested against it... as it is an old car and if there was work on the crank shaft.. i might not want to mess with it..

 

 

any advice would be appreciated...

[idosubaru]

completely unrelated and benign - get the pulley. just make sure you get a decent one that's made properly, balanced, etc.

 

seals leak with age, time, mileage, poor maintenance, etc. it's VERY common for seals to leak, particularly at 100,000+ or 10 years. i'd say it's more normal to have at least one leaky seal than it is to not have any...THAT would be strange.

[johnceggleston]

and, that pulley has to come off every time the timing belt is changed, so it was designed to be removed and replaced every 100k miles at the very least.

 

just make sure it is re-torqued properly, 125 ft. lbs i think.

if the bolt works lose, it can in fact ruin your crankshaft.

[bheinen74]

total waste of money to put a different pulley on. You will in fact throw off the factory balance from front to rear of the crank. It weighs what it does as to keep the weight balance from the rear flywheel/torque converter balanced with the front of the crank. Its the same principal as a spinning toy top, or a bicycle wheel. You don't want to remove weight/mass from one side and not the other. If you remove weight/mass from one end only, it throws it off, like a spinning top that wobbles. that wobble is hard on bearings, etc. YOU ARE ADDING STRAIN.

.

 

now, if you replace the flywheel/torque converter with lightweight to counter balance, then go ahead, otherwise you are just wasitng money.

[Reveeen]

i intend on putting a light weight pulley on the car to reduce strain...

 

Strain of what?

[bheinen74]

i intend on putting a light weight pulley on the car to reduce strain...

 

Strain of what?

 

go do this test. Go get a bicycle with a nicely balanced front wheel. Now, glue a bunch of lead weights to the left side of the tire, rim, all around the tire. Now try to ride the bike.

 

That is the same principal as when you lighten the one side of the crankshaft. enough said done

[idosubaru]

You will in fact throw off the factory balance from front to rear of the crank. It weighs what it does as to keep the weight balance from the rear flywheel/torque converter balanced with the front of the crank. Its the same principal as a spinning toy top, or a bicycle wheel. You don't want to remove weight/mass from one side and not the other. If you remove weight/mass from one end only, it throws it off, like a spinning top that wobbles. that wobble is hard on bearings, etc. YOU ARE ADDING STRAIN.

.

 

now, if you replace the flywheel/torque converter with lightweight to counter balance, then go ahead, otherwise you are just wasitng money.

um, i don't think he's bolting a tin can to his crank. that's very inaccurate and muddies up the waters. there's no real-world significance behind making minor changes to rotating components.

 

this shouldn't need to turn into an argument or oppinionated free-for-all. in the real world (not internet boards or sitting at a desk typing) this is done all the time, flywheels, harmonic balancers, crank pulleys, ligthweight pistons, light weight rods, cranks are reground when engines are rebuilt.....all of it is find so long as each piece is individually balanced and assembled corrrectly.

 

not too mention the pulley is loaded with accessory belt loads that can vary as well. minor, yes, but so is what you're talking about.

[idosubaru]

Go get a bicycle with a nicely balanced front wheel. Now, glue a bunch of lead weights to the left side of the tire, rim, all around the tire. Now try to ride the bike.

 

That is the same principal as when you lighten the one side of the crankshaft. enough said done

it's not the same. an intentionally unbalanced wheel does not replicate a system of balanced components.

 

the crank doesn't need to have the same weight on each end, which is what you are referring too. i would point you in the right direction or explain how moment of intertia works but that's not really the point - it's obvious you have an axe to grind about this. highly opinionated commentary is only going to hurt a new person that doesn't know any better.

[Reveeen]

go do this test.

 

You don't have to convince me, my "test" is at 325,000 miles, still going strong, without the so-called "aid" of a lightweight pulley.

 

there's no real-world significance behind making minor changes to rotating components.

 

None whatsoever, in fact, it may make matters worse, instead of "better". With a Curb Weight- sedans: 2885-3160. Wagons: 2905-3250 maybe leaving the spare tire at home might "improve things" more than ANY bogus pulley.

[idosubaru]

None whatsoever, in fact, it may make matters worse, instead of "better". With a Curb Weight- sedans: 2885-3160. Wagons: 2905-3250 maybe leaving the spare tire at home might "improve things" more than ANY bogus pulley.

rotating weight and vehicle weight are two completely different things. they are not related nor comparable. i'm sure there's plenty of reading on the internet about moment of inertia and rotating systems to explain this to you in some relevant way.

 

the amount of weight in the rotating system does affect engine performance, period. the weight in the vehicle affects it to a much lesser degree.

 

don't hear what i'm not saying though, i've made no claims whether the OP should get one, or whether i think they're worth it or not. i'll let him make that decision, hopefully on factual, credible information.

[Reveeen]

the amount of weight in the rotating system does affect engine performance, period.

 

Before you can come to the conclusion of the possible good/bad effects of messing with the rotating weight you have to consider the ENTIRE vehicle, rather than shooting in the dark and hoping that you are making a "good" decision, assuming:

1) the vehicle is not stripped out, or otherwise lightened.

2) the vehicle has an automatic transmission

3) there are no other engine mods affecting the power curve making it different from "stock"

 

There is little point (other than to dissipate some wealth) to changing a perfectly good engine pulley. In fact, there are situations that it would be beneficial to increase the rotating weight, rather than decrease it.

[Gloyale]

 

There is little point (other than to dissipate some wealth) to changing a perfectly good engine pulley. In fact, there are situations that it would be beneficial to increase the rotating weight, rather than decrease it.

 

The lighter, smaller diameter aftermarket pulleys have 3 big advantages.

 

1. If you are running high RPMS on a regular basis, you're alternator bearings are taking a high load. Smaller pulley, slightly slows the speed the alt rotates relative to engine RPMs.

 

2. Lightening the pulley is like lightening hte flywheel, or removing the clutch fan on older cars. You reduce the amount of power needed to accelerate the rotating parts= slight power gain.

 

3. Subaru Crank pulleys suck. They have that damn rubber bushing in them that likes to unglue and let the outer part slip around the center, or they just grenade entirely. A solid billet aluminum pulley cannot do this. It's the biggest reason to go aftermarket in my mind.

[idosubaru]

A solid billet aluminum pulley cannot do this. It's the biggest reason to go aftermarket in my mind.

that would be my opinion as well. that's a failure prone part (as encountered by anyone with more than anecdotal subaru experience). why not have a more reliable part, particularly for something that will strand you and cause severe engine damage on interference engines.

 

i'm not really trying to argue either way, i'd be up for an honest discussion and open forum about the possible negative consequences. but this isn't really about experience or real world applications, more like arm chair engineering. not trying to flame or start a war, but the demeanor and lack of discussion bare that out and it doesn't help the OP.

[frag]

What is the function of the rubber part in the pulley and why do you think this is not at all essential, to the point it could be replaced with a solid metal one?

Just want to know and probably others.

Thanks.

[Gloyale]

What is the function of the rubber part in the pulley and why do you think this is not at all essential, to the point it could be replaced with a solid metal one?

Just want to know and probably others.

Thanks.

 

It's there to make the motor vibrate less. Or rather to isolate those vibrations.

 

Just like the rubber in the motor mounts, it is meant to isolate the driver from the noise and vibration of the engine. Solid motor mounts would be more effiecient at transfering power and would never get sloppy, but they make the car shake.

 

The old standard GLs had a solid pulley. The MPFI ones got a 2 piece with the rubber. I've interchanged them and noticed almost no difference except not having to worry about it breaking.

[idosubaru]

What is the function of the rubber part in the pulley and why do you think this is not at all essential, to the point it could be replaced with a solid metal one?

oh come on...you're kidding right? you're just asking to stir the pot!?!?!??

 

the rubber is a dampening agent hence the term "harmonic dampener". it's meant to mitigate vibrations.

 

beyond that it's all opinion. the facts are that reports of engine issues due to solid pulleys is nearly nonexistent - i've never heard of any nor do i have any friends having problems with them. actually...a common fix for the broken stock pulley is to weld it back together. i don't recommend that but tons of people do it with no ill effects. and i'm sure it's not lined up perfectly or balanced at all....still no issues.

 

now...engine damage due to stock pulleys is well documented, happens regularly.

 

take your pick....arm chair intellectualism or real world experience.

[frag]

oh come on...you're kidding right? you're just asking to stir the pot!?!?!??

 

 

Well, if the truth lies at the bottom of the pot, why not stir it a little .

I was asking cause my car is at the end of its thirteenth year and this thread got me a little anxious about that pulley maybe about to play tricks on me.

[keltik]

Personally have seen 2 pulleys go bad and then had to personally tow those cars home.

 

I shall be fitting an aftermarket pulley to the turbo. as it rarely sees the low side of 4000rpm. I cant see the car gaining any testable performance from a new pulley, and this car IS stripped out.

 

Finally i wont have to worry about the dam thing breaking.

[idosubaru]

Well, if the truth lies at the bottom of the pot, why not stir it a little .

there's no "truth" to be had though. intelligent discussion is good, but if it's not your style please don't regurgitate t he arm chair antics that this kind of stuff will blow your engine up.

 

in a testing environment this would look something like this: a solid pulley will average 978,000 miles before causing failure that occurs on average at 980,000 miles on a stock pulley. it might be "true" but it's like saying driving with your CD case in the car adds weight and extra load to the engine, so you're shortening engine life. it's true from a technical, argumentative, stand point, but it's not realistic.

 

but the significant fact is that the stock two piece pulleys often fail during the actual real world mileages that owners keep and use their vehicles. do a search here...you'll see people with failed pulleys. it's not 'common', but it happens. i've seen it as well.

 

the "unicorn" is an engine failing because of a one piece pulley.

 

the solution to both problems if it bothers you...is buying a new pulley from Subaru (which will still be a two piece), but a good option for another 100,000 miles.

[uniberp]

NO one yet mentioned the probable fact that, if an aluminum pulley comes loose, wouldn't it do less damage to the crank than the OEM iron heavyweight? I use an Agency power now after the original slipped up.

 

there's no "truth" to be had though. intelligent discussion is good, but if it's not your style please don't regurgitate t he arm chair antics that this kind of stuff will blow your engine up.

 

in a testing environment this would look something like this: a solid pulley will average 978,000 miles before causing failure that occurs on average at 980,000 miles on a stock pulley. it might be "true" but it's like saying driving with your CD case in the car adds weight and extra load to the engine, so you're shortening engine life. it's true from a technical, argumentative, stand point, but it's not realistic.

 

but the significant fact is that the stock two piece pulleys often fail during the actual real world mileages that owners keep and use their vehicles. do a search here...you'll see people with failed pulleys. it's not 'common', but it happens. i've seen it as well.

 

the "unicorn" is an engine failing because of a one piece pulley.

 

the solution to both problems if it bothers you...is buying a new pulley from Subaru (which will still be a two piece), but a good option for another 100,000 miles.

[frag]

there's no "truth" to be had though. intelligent discussion is good, but if it's not your style please don't regurgitate t he arm chair antics that this kind of stuff will blow your engine up.

 

in a testing environment this would look something like this: a solid pulley will average 978,000 miles before causing failure that occurs on average at 980,000 miles on a stock pulley. it might be "true" but it's like saying driving with your CD case in the car adds weight and extra load to the engine, so you're shortening engine life. it's true from a technical, argumentative, stand point, but it's not realistic.

 

but the significant fact is that the stock two piece pulleys often fail during the actual real world mileages that owners keep and use their vehicles. do a search here...you'll see people with failed pulleys. it's not 'common', but it happens. i've seen it as well.

 

the "unicorn" is an engine failing because of a one piece pulley.

 

the solution to both problems if it bothers you...is buying a new pulley from Subaru (which will still be a two piece), but a good option for another 100,000 miles.

 

Hey, Grossgary, you're making all sorts of assumptions here. I only asked a question and replied to one of your sentence in a humorous way.

Nowhere did I wrote or even imply " that this kind of stuff will blow your engine off". You're also implying that maybe "intelligent discussion" is not my style. I find that insulting and uncalled for. You should reread the thread. Maybe you're confusing me with another poster.

Like I wrote in my last post, i'm only anxious to know if my well used (old) pulley should be replaced as preventive maintenance and if so with same or something else.

Cool down man!

[idosubaru]

Hey, Grossgary, you're making all sorts of assumptions here. I only asked a question and replied to one of your sentence in a humorous way.

Nowhere did I wrote or even imply " that this kind of stuff will blow your engine off".

AH! sorry, that wasn't referring to you at all. that reply was a general response to the entire thread...the misconceptions, lack of discussion and inaccurate analogies. i was partly joking too - about the "truth", since it's hard to determine even in a lab, much less in this thread.

[frag]

That's all right. I had'nt taken you first response seriously about «stirring the pot», that's why I answered like I did.

Case closed.

Have a good day.

[OB99W]

Engines with horizontally opposed cylinders minimize harmonic vibrations. Having fewer cylinders also helps, because the crankshaft can be shorter, lessening the tendency to twist. Proper counterbalancing of the crank also minimizes certain vibrations. So the H4 doesn't inherently require a lot of damping.

 

However, the opposing cylinders obviously aren't connected to the exact same place on the crank, so that balancing is imperfect, and torsional pulses exist under any circumstance. That's why crank pulley damping is useful, whether it's tuned for "harmonics" or not.

 

I'm not going to take sides on the issue of whether a solid, lightweight crank pulley could be detrimental, but here are some links for those interested in a bit more on the topic:

 

http://en.wikipedia.org/wiki/Torsional_vibration

http://www.fluidampr.com/TORSIONAL.html

http://www.fluidampr.com/FACTS.htm