Preventative maintenance
Thread Starter
Racer
Joined: Aug 2008
Posts: 493
Likes: 2
Preventative maintenance
So, everybody is saying I should replace my pilot bearing while my trans is out....its good practice they say.
The thing I am wondering is...what is the average lifespan of a pilot bearing? How many miles before failure?
The reason I ask is, a long time ago, when I was a student (a poor student mind you) and I was getting my ME degree, we briefly discussed failure. The thing I remembered is that the average part (that isn't manufactured magnificently), will have a fair number of failures during start up, with the majority of the remaining failures at the end of the life of the part (worn out). The start up failures due to defects, poor tolerance, ect.
So my question is, if you car has say 20k, you've clearly made it past the initial failure stage, and if the expected life is around 80k or so...why risk changing the part? You could just replace your good part with a defective part. Why go through the hassle of yanking it out (some people report having a hell of a time yanking these out). Why risk damaging the new one banging it in with a socket like we all do?
This goes for any part that isn't known to fail early...why bother???
Just something thats been running through my head today......
The thing I am wondering is...what is the average lifespan of a pilot bearing? How many miles before failure?
The reason I ask is, a long time ago, when I was a student (a poor student mind you) and I was getting my ME degree, we briefly discussed failure. The thing I remembered is that the average part (that isn't manufactured magnificently), will have a fair number of failures during start up, with the majority of the remaining failures at the end of the life of the part (worn out). The start up failures due to defects, poor tolerance, ect.
So my question is, if you car has say 20k, you've clearly made it past the initial failure stage, and if the expected life is around 80k or so...why risk changing the part? You could just replace your good part with a defective part. Why go through the hassle of yanking it out (some people report having a hell of a time yanking these out). Why risk damaging the new one banging it in with a socket like we all do?
This goes for any part that isn't known to fail early...why bother???
Just something thats been running through my head today......
Burning Brakes
Joined: Mar 2010
Posts: 1,189
Likes: 4
From: Freeport, FL
You sound as bad as me; placing too much thought into it.
Buy a quality pilot bearing and have a qualified tech install it.
You really don't want to go through the expense, time, and effort to replace the clutch and not include a vital, yet cheap, part such as the pilot bearing do you?
But, I do understand your concern. Just buy a quality bearing or bushing and you'll be just fine.
Buy a quality pilot bearing and have a qualified tech install it.
You really don't want to go through the expense, time, and effort to replace the clutch and not include a vital, yet cheap, part such as the pilot bearing do you?
But, I do understand your concern. Just buy a quality bearing or bushing and you'll be just fine.
Drifting
Joined: Feb 2007
Posts: 1,793
Likes: 7
From: Santa Maria Ca.
If you really want to be sure it won't fail,or get damaged while installing it,or when reinstalling the drivetrain,get a Kevlar/Composite pilot bushing.
I had a stock pilot bearing fail on startup (possibly my fault,not sure) so when I had to do the whole clutch job basically over again,I went with Kevlar,which is also very tolerant of a chewed up propshaft(which is what you'll have when the grenaded stock pilot bearing tears it up)
http://www.ramclutches.com/
about halfway down the page
Something to think about,mine's been in for about 8k miles,and it's working just fine...
I had a stock pilot bearing fail on startup (possibly my fault,not sure) so when I had to do the whole clutch job basically over again,I went with Kevlar,which is also very tolerant of a chewed up propshaft(which is what you'll have when the grenaded stock pilot bearing tears it up)
http://www.ramclutches.com/
about halfway down the page
Something to think about,mine's been in for about 8k miles,and it's working just fine...
Le Mans Master
Joined: Sep 2007
Posts: 7,604
Likes: 8
From: Belleville Il
Well,,you can't really put a mile value on it as would depend quite a bit on how the car is driven,,which goes for the whole clutch assembly!!That brings up the question as to what happened to the transmission?? i has an old Volvo 760 turbo 5 speed the was still going strong at about 270K when a tree fell on it!!Lots of highway miles,,not a lot of shifting. I will admit,, I'd be thinking more about the throw out bearing than the pilot bearing!! HOW MANY MILES on the original would be a major consideration. IF everything is aligned properly and running smoothly,,don't see a pilot as a high wear item IMO,,but that is just me! If you have miles on it,,go ahead and throw a new one in!!My sister had a car that went through several,,but found it to have a trans/pilot shaft misalignment problem!!
Thread Starter
Racer
Joined: Aug 2008
Posts: 493
Likes: 2
haha, yeah, I just hate the practice of replacing perfectly good parts. So on a side note, it seams like a lot of guys damage their pilot bearings when they reinstall the input shaft....how is this happening? Shouldn't the dowls on the bellhousing ensure alignment?
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
The pilot bearing... leave it. I see no reason in removing that sucker. Some guys have difficulty removing it and can cause more harm than good. In my practice I have always suggested replacing the slave cylinder and install a remote bleeder while I have a C5/C6 drive-line removed.
Whats the transmission out for?
Whats the transmission out for?
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Good old advice !
You sound as bad as me; placing too much thought into it.
Buy a quality pilot bearing and have a qualified tech install it.
You really don't want to go through the expense, time, and effort to replace the clutch and not include a vital, yet cheap, part such as the pilot bearing do you?
But, I do understand your concern. Just buy a quality bearing or bushing and you'll be just fine.
Buy a quality pilot bearing and have a qualified tech install it.
You really don't want to go through the expense, time, and effort to replace the clutch and not include a vital, yet cheap, part such as the pilot bearing do you?
But, I do understand your concern. Just buy a quality bearing or bushing and you'll be just fine.
I see both of your points, but in this case it's like going through all the trouble of installing a new kitchen with marbled counter top and a brand new disposal unit, but you go and re-use the old 6 inche loop drain pipe ? the thing costs like $ 5.99 and your going to re-use it in a $20K brand new kitchen.I'm 60 years old and have done my fair share of transmission swaps and I never would not stop at the local gear and clutch shop for a $5 brass pilot bearing before I put everything back together. If you've gone this far, how would you feel 2000 miles from here to find out trouble with your car and it's a dried up and shot pilot bearing ? This is really a no-brainer. Just put in a new bearing and consider it cheap insurance. Good luck and enjoy your newly repaired corvette.
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
I see both of your points, but in this case it's like going through all the trouble of installing a new kitchen with marbled counter top and a brand new disposal unit, but you go and re-use the old 6 inche loop drain pipe ? the thing costs like $ 5.99 and your going to re-use it in a $20K brand new kitchen.I'm 60 years old and have done my fair share of transmission swaps and I never would not stop at the local gear and clutch shop for a $5 brass pilot bearing before I put everything back together. If you've gone this far, how would you feel 2000 miles from here to find out trouble with your car and it's a dried up and shot pilot bearing ? This is really a no-brainer. Just put in a new bearing and consider it cheap insurance. Good luck and enjoy your newly repaired corvette.
As a Corvette Tech, this saying is very true in many aspects. For a 20k mile car, that pilot bearing has no reason to come out. The wear on the bearing matches the wear on the drive shaft. If it were me I'd feel perfectly fine about leaving it in there.
If I were to pull the drive-line out of a 20k mile car for a transmission failure and call the customer suggesting to replace the clutch, they'd laugh at me. And that's the clutch! A wear item! The pilot bearing should last much longer than a clutch.
I would offer the opportunity to replace it, but I wouldn't say you'd need to or should. Just my $.02.
Pro
Joined: Aug 2010
Posts: 545
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From: Calgary Alberta
A good mechanic should be able to tell you if the bearing is reusable. If they are dry, lube has leaked they will spin for a long time with a finger flick. If the lube is good and the bearing does not have excessive play it will spin maybe a turn or so with the same finger flick. That said if I take a motor apart, electric is where my experience is, I will always throw a fresh bearing in. If you consider the labour and materials involved with replacing just the bearing it's a tough decision.
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For the cheap price, I'd go ahead and change it.
Thread Starter
Racer
Joined: Aug 2008
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A good mechanic should be able to tell you if the bearing is reusable. If they are dry, lube has leaked they will spin for a long time with a finger flick. If the lube is good and the bearing does not have excessive play it will spin maybe a turn or so with the same finger flick. That said if I take a motor apart, electric is where my experience is, I will always throw a fresh bearing in. If you consider the labour and materials involved with replacing just the bearing it's a tough decision.
Drifting
Joined: Feb 2007
Posts: 1,793
Likes: 7
From: Santa Maria Ca.
That means the grease is all gone and it'll grenade about 5k miles after you put it back together.
But maybe not,whatever-it's just a quick 12 hour job to change it,so you might as well wait till it really needs it before you do it....
But maybe not,whatever-it's just a quick 12 hour job to change it,so you might as well wait till it really needs it before you do it....
Last edited by Carcass; Oct 16, 2010 at 01:28 AM.
Burning Brakes
Joined: Mar 2010
Posts: 1,186
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From: North Topsail Beach NC
I'm presently going through the same thing with the "other" hobby, my 30 foot boat. When, about a month ago, it abruptly became time to replace the engine, it made sense to do replace a bunch of other stuff that I wouldn't have ordinarily replaced until it failed, just because the engine was out and it made things much more easily accessible.
I feel the same way about not wanting to replace items that are still good, but know that at least with a 10 year old boat there are things that will ultimately go wrong and given my luck, they will fail immediately after the new engine is bolted in.
I feel the same way about not wanting to replace items that are still good, but know that at least with a 10 year old boat there are things that will ultimately go wrong and given my luck, they will fail immediately after the new engine is bolted in.
Thread Starter
Racer
Joined: Aug 2008
Posts: 493
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can you just throw some bearing grease on him....
Resident moron
Joined: Jun 2003
Posts: 4,746
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From: Assachusetts
I was in the same dilemma when I toasted my clutch and my 3rd gear synchro at about 25k miles. I replaced the pilot bearing when I pulled the drivetrain. That was 7 years ago and it's been fine ever since.
Cheap maintenance, IMO.
Dope
Cheap maintenance, IMO.
Dope
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