crankshaft bearing problem
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On The Tree
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crankshaft bearing HELP!!! Well i took my car to GM crappywrench to fix what i thought was a clutch problem, but come to find out they said my crankshaft bearing is very worn out and somehow the crankshaft is like ruined and I need a new crankshaft or everything is going to break very soon.
When i push the clutch all the way to the floor you can hear this grinding sort of shattering ticking noise and the guy at GM told me that i am hearing something going wrong with the crankshaft? Can someone help explain this to me better?
I am so confused....What are the causes of a worn out crankshaft bearing and why would i need a whole new crankshaft? He said if i keep driving my car its gonna break and destroy the engine. Do i need a second opinion? lol What are my options? I didnt think stuff like this went wrong on a engine that only has 102,000 miles? Sorry this is kind of long.
BEN
When i push the clutch all the way to the floor you can hear this grinding sort of shattering ticking noise and the guy at GM told me that i am hearing something going wrong with the crankshaft? Can someone help explain this to me better?
I am so confused....What are the causes of a worn out crankshaft bearing and why would i need a whole new crankshaft? He said if i keep driving my car its gonna break and destroy the engine. Do i need a second opinion? lol What are my options? I didnt think stuff like this went wrong on a engine that only has 102,000 miles? Sorry this is kind of long.
BEN
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Did they actually pull the oil pan, unbolt the crank and visually inspect the bearings/journals? My guess is no?
A spun bearing usually sounds like a LOUD knocking noise, constant regardless of clutch engagement -- actually sounds wooden like someone knocking on a door. NOT a good noise.
If you only hear a noise when depressing the clutch pedal, that would lead me to believe it's associated with the transmission/clutch -- not the motor. Pressing the clutch in disengages the clutch by pulling on the throw-out bearing. Perhaps you've got something torn up along those lines (clutch disc/pressure plate/throwout bearing/clutch fork). Could you describe the noise a little more? Stock clutch?
IOW, yes, I'd get a second opinion...
A spun bearing usually sounds like a LOUD knocking noise, constant regardless of clutch engagement -- actually sounds wooden like someone knocking on a door. NOT a good noise.
If you only hear a noise when depressing the clutch pedal, that would lead me to believe it's associated with the transmission/clutch -- not the motor. Pressing the clutch in disengages the clutch by pulling on the throw-out bearing. Perhaps you've got something torn up along those lines (clutch disc/pressure plate/throwout bearing/clutch fork). Could you describe the noise a little more? Stock clutch?
IOW, yes, I'd get a second opinion...
Pushing the clutch certainly doesn't engage/disengage the engine bearings! Bad engine bearings would be noticeable all the time, not when the clutch is depressed. I would venture to say it is something to do with your your clutch or pressure plate (hence the noise when the clutch pedal is depressed). Find someone that knows what they are doing!
Thread Starter
On The Tree
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I am thinking maybe he doesnt know what he is doing either because they open at like 8 am or sumthing and he called me at 10 am and told me i needed a new crankshaft, theres no way they inspected that in 2 hours. The clutch is stock and it is still under warrenty...maybe they dont want to waste their own money on a new one and are trying to take me for a ride because i am only 21 and i look more like 17 so maybe they thought they could rip me off? Maybe i should go talk to someone higher up on command over there at old GM crappywrench.
BEN
BEN
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i dont think he pulled the pan, because i've done those before and it takes longer than 2 hours. after you pull the pan you have to pull the main caps and check the bearings and then check the crank. look under the car and see if you can tell if the oil pan was taken off. i think they are tryin to take your money
My wife's old Mazda had a pilot bearing (it's inside the crank) sieze up, and it made a squealing sound when the clutch pedal was pushed in. One of the rollers had frozen, and the pilot bearing didn't spin any more. The snout of the trans rides on the pilot bearing, and the pilot bearing is press fit in to the crank. FWIW, the pilot bearing is a $14 item and can easily be replaced without doing anything to the crank.
If, perhaps, your pilot bearing was in really bad shape and/or fell apart, I could see how the snout of the trans could maybe start to warble the crank a little.... maybe. It would make screeching and/or grinding noises, yes.
No matter what, I'd go over there and take a look at this "bad part" before authorizing ANY work. Their response sounds pretty vague.
If, perhaps, your pilot bearing was in really bad shape and/or fell apart, I could see how the snout of the trans could maybe start to warble the crank a little.... maybe. It would make screeching and/or grinding noises, yes.
No matter what, I'd go over there and take a look at this "bad part" before authorizing ANY work. Their response sounds pretty vague.
Last edited by Camaroholic; Feb 18, 2005 at 01:04 PM.
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On The Tree
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Ok i went to GM.....Please read Well I talked to the mechanic at GM today about my clutch/crankshaft noise and what he said was the crankshaft bearing is so worn out that the cranshaft is moving back and forth about .40 inches and so its like barely touching the clutch pressure plate and so when i press the clutch hard to the floor it makes a grinding noise.
They told me that just replacing the bearing wont help because the crankshaft is old and is probably worn too...
They said the car is drivable for a while but probably not all that long.
Why cant i just replace the bearing? How does the crankshaft get ruined in the process? Should i check the oil to see if there is flakes in it? If the crankshaft is moving back and forth how long can i expect the car to go, can anything else go wrong? Is it time for a 383 rebuild?
Thanks for all your help.
BEN
They told me that just replacing the bearing wont help because the crankshaft is old and is probably worn too...
They said the car is drivable for a while but probably not all that long.
Why cant i just replace the bearing? How does the crankshaft get ruined in the process? Should i check the oil to see if there is flakes in it? If the crankshaft is moving back and forth how long can i expect the car to go, can anything else go wrong? Is it time for a 383 rebuild?
Thanks for all your help. BEN
Is he talking about the pilot bearing? If the entire crank is moving 0.4 inches back and forth, the engine is hosed!! If it is just the pilot bearing, you should be able to replace it and put a new clutch in it.
Crank walk, although rare on SBC's, can occur. This usually happens with high loads placed horizontally (front to back along crankshaft centerline) against the rotating assembly such as a pressure plate with high clamping pressures etc.. You don't need to pull the pan to find this, it's called measuring the thrust play (or endplay). All you need to do is place a prybar between the flywheel and the block and measure how much it moves back and forth (front to back of the engine). And yes, if you do in fact have excessive crank endplay, you will have clutch engagement problems and probably will hear strange noises if it's really that bad....
What happens is that the thrust bearing wears into the crank. Once that happens you really just need a new crank and a rebuild.
Sorry man, but you can always get a second opinion....
Mike
What happens is that the thrust bearing wears into the crank. Once that happens you really just need a new crank and a rebuild.
Sorry man, but you can always get a second opinion....
Mike
Originally Posted by Mikey 97Z M6
Crank walk, although rare on SBC's, can occur. This usually happens with high loads placed horizontally (front to back along crankshaft centerline) against the rotating assembly such as a pressure plate with high clamping pressures etc.. You don't need to pull the pan to find this, it's called measuring the thrust play (or endplay). All you need to do is place a prybar between the flywheel and the block and measure how much it moves back and forth (front to back of the engine). And yes, if you do in fact have excessive crank endplay, you will have clutch engagement problems and probably will hear strange noises if it's really that bad....
What happens is that the thrust bearing wears into the crank. Once that happens you really just need a new crank and a rebuild.
Sorry man, but you can always get a second opinion....
Mike
What happens is that the thrust bearing wears into the crank. Once that happens you really just need a new crank and a rebuild.
Sorry man, but you can always get a second opinion....
Mike
Joined: May 2004
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From: Halfway back on the Highway to Hell...again!
crank endplay moving .400 is almost impossible. The rods won't allow it to move that much. If it is, you've got serious problems. Think about this... .400 is almost a 1/2 inch. .040 possibly. Also, crank endplay will not affect clamping force. The entire clutch assy it connected to the flywheel, connected to the crank. There is no way .040 will affect engagement of the tranny.
If your crank has more than .015 of end play...time for a rebuild...if that's the case. My opinion of most GM techs is not of high character. They can take that piece of paper and shove it. Some others though, are wizards and geniuses. take it to a good tranny shop to have them diagnose it. they know more than GM techs when it comes to clutches. A GOOD tranny shop.
If your crank has more than .015 of end play...time for a rebuild...if that's the case. My opinion of most GM techs is not of high character. They can take that piece of paper and shove it. Some others though, are wizards and geniuses. take it to a good tranny shop to have them diagnose it. they know more than GM techs when it comes to clutches. A GOOD tranny shop.
sappers right. the clutch and flywheel are connected directly to the crankshaft. if the crankshaft moves the clutch/flywheel move with it.
im my experience i have found that some of the oldest and sometimes crummiest places will know the most and do the best work with transmissions. experience counts for a lot. sure a chain may have been around a long time, but the employees havent been i bet.
im my experience i have found that some of the oldest and sometimes crummiest places will know the most and do the best work with transmissions. experience counts for a lot. sure a chain may have been around a long time, but the employees havent been i bet.
Originally Posted by SAPPER
Also, crank endplay will not affect clamping force. The entire clutch assy it connected to the flywheel, connected to the crank.
Either way, if you have excessive crank endplay, you're looking at a rebuild.
Mike
