Front wheel bearing?
#16
Chronic Tool Dropper
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the problem with luck i guess, is that it can sway you to push it! I did this at the track when i had a realy noisy one many years ago.. that bearing never had an issue. so, im trying it again. the race didnt look bad, so off we went. heck, whats the worst that can happen... ill have to buy the bearings again?? i dont think they were too expensive and i didnt have access to a press.
I generally admire the way you have managed to use your driving skills to work around shortcomings on your 928. What irritates me is that you seem to purposely put up extra hurtles for yourself and the car. I have a client that shortchanges maintenance in a power plant with a goal of reducing maintenance expenses. It's almost a game to him to see how much cutting he can get away with, like a business-school exercise almost. Major catastrophes are becoming more common after a couple years of this, with multi-million dollar repair bills and many more millions lost to missed generation opportunities and the need to supply replacement power for a contract. Yet he still operates his business this way.
For less than an hour of effort, and the costs of four bearings and a couple seals, you are playing the same game. Not "Do it like you mean it and never worry." Rather "I'll just half-fast this simple yet critical job, and then watch to see how long it goes before it gives up. This is fun!" For just the tiniest amount of extra effort, you can do the whole job right.
Never check or change the engine oil. Let's see how long it goes before it gives up. This is fun!
#19
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Mark, see my post #8 on damage to the spindle. It's what happens when you ride on noisy bearings. Your car is fitted with stock exhaust, right? So it will be easy to hear a failing bearing grumble a little.
I generally admire the way you have managed to use your driving skills to work around shortcomings on your 928. What irritates me is that you seem to purposely put up extra hurtles for yourself and the car. I have a client that shortchanges maintenance in a power plant with a goal of reducing maintenance expenses. It's almost a game to him to see how much cutting he can get away with, like a business-school exercise almost. Major catastrophes are becoming more common after a couple years of this, with multi-million dollar repair bills and many more millions lost to missed generation opportunities and the need to supply replacement power for a contract. Yet he still operates his business this way.
For less than an hour of effort, and the costs of four bearings and a couple seals, you are playing the same game. Not "Do it like you mean it and never worry." Rather "I'll just half-fast this simple yet critical job, and then watch to see how long it goes before it gives up. This is fun!" For just the tiniest amount of extra effort, you can do the whole job right.
Never check or change the engine oil. Let's see how long it goes before it gives up. This is fun!
I generally admire the way you have managed to use your driving skills to work around shortcomings on your 928. What irritates me is that you seem to purposely put up extra hurtles for yourself and the car. I have a client that shortchanges maintenance in a power plant with a goal of reducing maintenance expenses. It's almost a game to him to see how much cutting he can get away with, like a business-school exercise almost. Major catastrophes are becoming more common after a couple years of this, with multi-million dollar repair bills and many more millions lost to missed generation opportunities and the need to supply replacement power for a contract. Yet he still operates his business this way.
For less than an hour of effort, and the costs of four bearings and a couple seals, you are playing the same game. Not "Do it like you mean it and never worry." Rather "I'll just half-fast this simple yet critical job, and then watch to see how long it goes before it gives up. This is fun!" For just the tiniest amount of extra effort, you can do the whole job right.
Never check or change the engine oil. Let's see how long it goes before it gives up. This is fun!
here are the pics... the inside bearing is crunchy and the outside bearing feels fine..... even in the new races the inner bearing feels bad.. i didint see any damage or scoring on the innner bearing hub race, so thats why i just put new bearings back in. again.. ive done it before with no issues ,and they had to be changed and i didnt think i could do it without the press.
As far as cutting corners, i dont do it too often, with out calculating the risks. (i.e. used tires, etc) in this case, the wheel bearing could fail sooner, but like i say, its a cheap set of parts.
Here is the picture of the old bearing and the new races. this thing howled on right turns.... loud! but , no visible wear
I dont think there is a chance of spindle wear at this point, as physically everything was lined up pretty well and nothing was over the edge digging into the spindle which had sharp machined corners at the bearing mounting surface.
#20
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the bearing rollers look fine. the failure in this bearing seems to be in the bearing structure ... there wouldnt be much, if any race wear.
here is magnified picture of the bearing roller.usually, this material is the toughest of the system, as well as the race, but the structure is usually weaker and the axial support structure can wear and be damaged to cause wear and vibration. that same bearing,if not worn, will not unusually wear the old races if the old races are in good shape.. i suspect that they are and this entire decision is a cheap bet. had it have been a rear bearing.. no way would i have chanced it.
here is magnified picture of the bearing roller.usually, this material is the toughest of the system, as well as the race, but the structure is usually weaker and the axial support structure can wear and be damaged to cause wear and vibration. that same bearing,if not worn, will not unusually wear the old races if the old races are in good shape.. i suspect that they are and this entire decision is a cheap bet. had it have been a rear bearing.. no way would i have chanced it.
#21
Chronic Tool Dropper
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Your close-in picture shows discoloration due to overheating, and galling due to vibration. They are way far gone. Hope you could see the micro ground finish on the new rollers for comparison.
If you want a taste of what the cups in the car look like, pull the cage and rollers off the inner race. Wear on the bearing surface there will be very similar to what's in the cup. If it isn't still bright silver with the micro-grind finish, it's toast.
Humor me some: Disassemble the hub you just worked on and replace the cups. Clean the spindle thoroughly, and share pictures of the area where the inner race sits against the shoulder both top and bottom. Grab pics of the bearing cups in the hub, clean, before you bake them to remove the cups, so we can see the color and the finish on the bearing surfaces.
When installed correctly, lubricated and adjusted correctly, there is no metal-to-metal contact in these tapered bearings at all. So no polishing, galling, heat-related discoloration, pitting or other damage. If you see any of that, it's time to figure out why and do something to keep it from happening to the new bearings you will install.
If you want a taste of what the cups in the car look like, pull the cage and rollers off the inner race. Wear on the bearing surface there will be very similar to what's in the cup. If it isn't still bright silver with the micro-grind finish, it's toast.
Humor me some: Disassemble the hub you just worked on and replace the cups. Clean the spindle thoroughly, and share pictures of the area where the inner race sits against the shoulder both top and bottom. Grab pics of the bearing cups in the hub, clean, before you bake them to remove the cups, so we can see the color and the finish on the bearing surfaces.
When installed correctly, lubricated and adjusted correctly, there is no metal-to-metal contact in these tapered bearings at all. So no polishing, galling, heat-related discoloration, pitting or other damage. If you see any of that, it's time to figure out why and do something to keep it from happening to the new bearings you will install.
#22
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New bearings, new seals ... cheap no brainer routine service replacement. Why even contemplate less?
#23
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+928 .... I'll bet there's some wear and ridges on the spindles, that you'll only see once you have the spindle cleaned with solvent, but which allow enough movement to make it impossible to get rid of all play.
New bearings, new seals ... cheap no brainer routine service replacement. Why even contemplate less?
New bearings, new seals ... cheap no brainer routine service replacement. Why even contemplate less?
again, the spindles get no wear and there is nothing even close that touches them... i sized it all up and rotated the stuff on the car. nothing was close to the spiindle and the bearing inner diameter has NO signe of movement
Last edited by mark kibort; 10-14-2015 at 01:48 PM.
#24
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Your close-in picture shows discoloration due to overheating, and galling due to vibration. They are way far gone. Hope you could see the micro ground finish on the new rollers for comparison.
If you want a taste of what the cups in the car look like, pull the cage and rollers off the inner race. Wear on the bearing surface there will be very similar to what's in the cup. If it isn't still bright silver with the micro-grind finish, it's toast.
Humor me some: Disassemble the hub you just worked on and replace the cups. Clean the spindle thoroughly, and share pictures of the area where the inner race sits against the shoulder both top and bottom. Grab pics of the bearing cups in the hub, clean, before you bake them to remove the cups, so we can see the color and the finish on the bearing surfaces.
When installed correctly, lubricated and adjusted correctly, there is no metal-to-metal contact in these tapered bearings at all. So no polishing, galling, heat-related discoloration, pitting or other damage. If you see any of that, it's time to figure out why and do something to keep it from happening to the new bearings you will install.
If you want a taste of what the cups in the car look like, pull the cage and rollers off the inner race. Wear on the bearing surface there will be very similar to what's in the cup. If it isn't still bright silver with the micro-grind finish, it's toast.
Humor me some: Disassemble the hub you just worked on and replace the cups. Clean the spindle thoroughly, and share pictures of the area where the inner race sits against the shoulder both top and bottom. Grab pics of the bearing cups in the hub, clean, before you bake them to remove the cups, so we can see the color and the finish on the bearing surfaces.
When installed correctly, lubricated and adjusted correctly, there is no metal-to-metal contact in these tapered bearings at all. So no polishing, galling, heat-related discoloration, pitting or other damage. If you see any of that, it's time to figure out why and do something to keep it from happening to the new bearings you will install.
#25
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wear on the spindle???? no way... why in the heck would you suspect that??? the bearinig has to move out of the races to touch the spindle edges all the forces are kept in the bearing cage. nothing goes near the spindle or rides on the spindle. its not a wear surface , its only a position surface.when the bearing inner diameter meets the spindle, it stops. the bearing between the spindle and the hub, moves with the hub. the only wear is going to be on the inner race , the edges of the cage under high g loading, and the outer race that i left in place because it looked perfect..... as did the outer race in the hub.
again, the spindles get no wear and there is nothing even close that touches them... i sized it all up and rotated the stuff on the car. nothing was close to the spiindle and the bearing inner diameter has NO signe of movement
again, the spindles get no wear and there is nothing even close that touches them... i sized it all up and rotated the stuff on the car. nothing was close to the spiindle and the bearing inner diameter has NO signe of movement
It's common wear that I've seen on many spindles, where the inner diameter of the bearing moves on the spindle, when adjustment of the bearing slackens off with wear, and leaves a wear ridge on the spindle underside. When that wear is present, you can adjust the bearing up correctly, and there's still rock of the hub.
Edit: You obviously don't read or seriously consider what others post in response to your query (such as post #8), and just rattle on regardless, because you consider yourself infallible. It makes me wonder why you ask for advice, when all you do is contradict with your own view of 'The World According To Kibort', and do what you were going to do in the first place anyway.
BTW ... you could have spared me the capitalization and multiple question marks ... I'd already concluded that you believe you are the repository of all 928 knowledge and driving skills.
Carry on ... I'm confident you will.
Last edited by Dave928S; 10-15-2015 at 06:12 AM. Reason: .... and ... I could say more
#26
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Because I've seen it, felt it, and measured it!!
It's common wear that I've seen on many spindles, where the inner diameter of the bearing moves on the spindle, when adjustment of the bearing slackens off with wear, and leaves a wear ridge on the spindle underside. When that wear is present, you can adjust the bearing up correctly, and there's still rock of the hub.
It's common wear that I've seen on many spindles, where the inner diameter of the bearing moves on the spindle, when adjustment of the bearing slackens off with wear, and leaves a wear ridge on the spindle underside. When that wear is present, you can adjust the bearing up correctly, and there's still rock of the hub.
This boy is unteachable.
Put him on "ignore" and move on.
#28
Chronic Tool Dropper
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I took them apart and this is what i saw. i was expecting the outer edges (holed side of the rollers) to have some unusual wear, but it wasnt that bad. the grinding feeling and howlinig noise was due to good old fashion wear on the inner bearing race.. the bearings look actually good. the race is toast! but odly enough, the race in the car's hub looks perfect. very shiney and new looking. maybe because there is more force because the speed is moving slower on the inner race . (just a guess) . maybe becaue the race material on the hub portion is harder than the part on the inner bearing? whatever the case, the race in the car looked very nice and no wear seen... nothing like what this pic shows on the bearing. more than likely, the bearing inner sees more force PSI vs the outer because of the circumference being quite a bit larger on the outer race that fits in the hub. the chamfered edges of the "hole" side, that sees the forces on high g loading didnt look disturbed.
On the spindle: The bearing you show had severe vibration associated with failure, evidenced by the galling. The sound you heard was that vibration, transmitted through the cup to the spindle. Do you think you would have heard just the bearing if it wasn't transmitting the vibration through the spindle? With race exhaust, earplugs and your helmet on?
The inner bearing cup is a barely interference fit on the spindle. In most installations, there's a thin film of graese that ends up there, but the fit is metal-to-metal. Look at the fit and finish of a new spindle, and find that it's very precise. Once you have bearing vibration as you experienced, you'll find that the vibration causes wear on the spindle at the bottom where the load is passed from cup to spindle. The area looks polished, and in severe cases can be worn from the bearing cone actually spinning on the spindle. The spindle needs to support the cone in perfect alignment, so if you can slide a new cone onto a clean spindle and have an even fit (by feel), with absolutely no rocking available, you might be OK. But you need to make a visual check of the bottom loaded surfaces of the spindle where the bearing rides. If it's visibly polished, the spindle needs to be replaced since it will no longer reliably support the bearing.
Mark, we don't pull this stuff out of our butts just to needle you. There's a weath of knowledge and experience behind all these recommendations. Learn from it, take advantage of it. Consider that "the first stage is denial." Roll quickly through the denial stage, pull the wheels and hubs off again so you can progress to the discovery stage. Inspection will lead you to the analysis stage. You can postulate and speculate 'til the cows come home. Based on the many accumulated years of knowledge and experience guiding you here, we are telling you what you'll see and why. Do you think that cone and roller you disassembled is the first one I/we have seen like that? Why would we even suggest that inspection do you think? Others already know what's happened, and have dealt with the fringe benefits like the collateral damage to the spindle. And with drastically shortened bearing life that goes with leaving the damaged cup in there with the new rollers and cone.
Don't post back until you've taken the time to remove the hub again and inspect the spindle. Take pictures of the top and bottom areas where the inner bearing rides, and share the pictures. Dime to a donut, the bottom of the spindle will be worn.
While the hub is off, replace both bearings complete. If you've not driven on the new cones in the old cups, they may be OK to put back in. But bearings are cheap, no need to risk further problems for a few dollars.
Do the other side too.
#29
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Because I've seen it, felt it, and measured it!!
It's common wear that I've seen on many spindles, where the inner diameter of the bearing moves on the spindle, when adjustment of the bearing slackens off with wear, and leaves a wear ridge on the spindle underside. When that wear is present, you can adjust the bearing up correctly, and there's still rock of the hub.
Edit: You obviously don't read or seriously consider what others post in response to your query (such as post #8), and just rattle on regardless, because you consider yourself infallible. It makes me wonder why you ask for advice, when all you do is contradict with your own view of 'The World According To Kibort', and do what you were going to do in the first place anyway.
BTW ... you could have spared me the capitalization and multiple question marks ... I'd already concluded that you believe you are the repository of all 928 knowledge and driving skills.
Carry on ... I'm confident you will.
It's common wear that I've seen on many spindles, where the inner diameter of the bearing moves on the spindle, when adjustment of the bearing slackens off with wear, and leaves a wear ridge on the spindle underside. When that wear is present, you can adjust the bearing up correctly, and there's still rock of the hub.
Edit: You obviously don't read or seriously consider what others post in response to your query (such as post #8), and just rattle on regardless, because you consider yourself infallible. It makes me wonder why you ask for advice, when all you do is contradict with your own view of 'The World According To Kibort', and do what you were going to do in the first place anyway.
BTW ... you could have spared me the capitalization and multiple question marks ... I'd already concluded that you believe you are the repository of all 928 knowledge and driving skills.
Carry on ... I'm confident you will.
Now you are getting all worked up.... sorry i used the capitals.
EDIT.. I understand. why didnt you say that? (or maybe i ididnt understand your point.... ) .. usually.. . the bearing can onnly spin on the spindle if things are REALLY messed up. My bearing is not moving on the spindle there is no wear and its a tight , even fit. but i agree, if that kind of wear happened, sure you would never get the bearings to be tight, beause that gap of the bearing and spindle would always be there. no, thats not what has happened... i had some accelerated wear and the bearings are toast. however, the hub race looks nothing like the bearing race.... keep in mind, its seeing a lot more force than the outer race and thats why it probably fails first.
#30
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I understand what you are saying... but i also saw what i saw... didnt look as closely, because everything seemed to fit so well, especially when i put the new bearing on the spiindle. very tight no rocking. BUT , for this discussion and my own education, ill go out and pull it apart and take a look again. i dont want to be banging on the hub to get the old race out, that was my trade off thought when i used the old one. it looked very smooth, but the only risk if it is not damaged is the microfinish is gone that holds the grease film, correct?
Look, i understand the concern and appreciate the info... but i too have a lot of experience putting bearings back in and never having issues again, even leaving the old races in place. ive done that about 4-5 times on different chassis. however, its not to say that its right or it will last as long, but i didint have any more bearing noise and hub adjustability was still firm and stable.
BUT, i will remove the set up for the sake of the discussion and risk aversion to what might happen if i overlooked those races having some real bad scoring or if the spindle is worn on the bottom and will take some pics.
so, you are saying that i can pound those races out and press the new ones in without using a press. i know putting the new ones in by freezing the races, will make it go in easier (and heating the hubs in the BBQ )
I havent driven the car yet..... so ill pull it and see what we got.
Mk
And GUYS , I guess you can see that im taking this a little lighter than most of you. its not because im not listening,its because i dont see that much risk here. whats the worse that can happen.. ill start hearing noise again after 6 race weekends.....? and then illl replace the bearings the right way.. the only draw back is if that vibration and failure has caused the inner bearing to move on the spindle shaft and damage it .. It didnt move and the shaft looked good so Ill post pics.
Look, i understand the concern and appreciate the info... but i too have a lot of experience putting bearings back in and never having issues again, even leaving the old races in place. ive done that about 4-5 times on different chassis. however, its not to say that its right or it will last as long, but i didint have any more bearing noise and hub adjustability was still firm and stable.
BUT, i will remove the set up for the sake of the discussion and risk aversion to what might happen if i overlooked those races having some real bad scoring or if the spindle is worn on the bottom and will take some pics.
so, you are saying that i can pound those races out and press the new ones in without using a press. i know putting the new ones in by freezing the races, will make it go in easier (and heating the hubs in the BBQ )
I havent driven the car yet..... so ill pull it and see what we got.
Mk
And GUYS , I guess you can see that im taking this a little lighter than most of you. its not because im not listening,its because i dont see that much risk here. whats the worse that can happen.. ill start hearing noise again after 6 race weekends.....? and then illl replace the bearings the right way.. the only draw back is if that vibration and failure has caused the inner bearing to move on the spindle shaft and damage it .. It didnt move and the shaft looked good so Ill post pics.
Um, those rollers look like crap. They were overheated and they are pitted and worn. There's no magic to how these bearings work, with a thin film of lubrication needed between the loaded parts. There is no metal-to-metal contact, always a film of lubrication. When that film fails and you do have metal-to-metal contact, the metal pieces are quickly destroyed. Your bearing is a textbook case, with a galled inner race where heat actually caused the metal to move. Guess where that heat came from and where it went? The rollers transfer the heat and the molten metal bits to the other race too, the 'cup' that is in the hub. It is similarly blued from overheating, the micro-grind finish is destroyed so it will have trouble holding lubrication. The parts you put in, the cone and rollers, are doomed.
On the spindle: The bearing you show had severe vibration associated with failure, evidenced by the galling. The sound you heard was that vibration, transmitted through the cup to the spindle. Do you think you would have heard just the bearing if it wasn't transmitting the vibration through the spindle? With race exhaust, earplugs and your helmet on?
The inner bearing cup is a barely interference fit on the spindle. In most installations, there's a thin film of graese that ends up there, but the fit is metal-to-metal. Look at the fit and finish of a new spindle, and find that it's very precise. Once you have bearing vibration as you experienced, you'll find that the vibration causes wear on the spindle at the bottom where the load is passed from cup to spindle. The area looks polished, and in severe cases can be worn from the bearing cone actually spinning on the spindle. The spindle needs to support the cone in perfect alignment, so if you can slide a new cone onto a clean spindle and have an even fit (by feel), with absolutely no rocking available, you might be OK. But you need to make a visual check of the bottom loaded surfaces of the spindle where the bearing rides. If it's visibly polished, the spindle needs to be replaced since it will no longer reliably support the bearing.
Mark, we don't pull this stuff out of our butts just to needle you. There's a weath of knowledge and experience behind all these recommendations. Learn from it, take advantage of it. Consider that "the first stage is denial." Roll quickly through the denial stage, pull the wheels and hubs off again so you can progress to the discovery stage. Inspection will lead you to the analysis stage. You can postulate and speculate 'til the cows come home. Based on the many accumulated years of knowledge and experience guiding you here, we are telling you what you'll see and why. Do you think that cone and roller you disassembled is the first one I/we have seen like that? Why would we even suggest that inspection do you think? Others already know what's happened, and have dealt with the fringe benefits like the collateral damage to the spindle. And with drastically shortened bearing life that goes with leaving the damaged cup in there with the new rollers and cone.
Don't post back until you've taken the time to remove the hub again and inspect the spindle. Take pictures of the top and bottom areas where the inner bearing rides, and share the pictures. Dime to a donut, the bottom of the spindle will be worn.
While the hub is off, replace both bearings complete. If you've not driven on the new cones in the old cups, they may be OK to put back in. But bearings are cheap, no need to risk further problems for a few dollars.
Do the other side too.
On the spindle: The bearing you show had severe vibration associated with failure, evidenced by the galling. The sound you heard was that vibration, transmitted through the cup to the spindle. Do you think you would have heard just the bearing if it wasn't transmitting the vibration through the spindle? With race exhaust, earplugs and your helmet on?
The inner bearing cup is a barely interference fit on the spindle. In most installations, there's a thin film of graese that ends up there, but the fit is metal-to-metal. Look at the fit and finish of a new spindle, and find that it's very precise. Once you have bearing vibration as you experienced, you'll find that the vibration causes wear on the spindle at the bottom where the load is passed from cup to spindle. The area looks polished, and in severe cases can be worn from the bearing cone actually spinning on the spindle. The spindle needs to support the cone in perfect alignment, so if you can slide a new cone onto a clean spindle and have an even fit (by feel), with absolutely no rocking available, you might be OK. But you need to make a visual check of the bottom loaded surfaces of the spindle where the bearing rides. If it's visibly polished, the spindle needs to be replaced since it will no longer reliably support the bearing.
Mark, we don't pull this stuff out of our butts just to needle you. There's a weath of knowledge and experience behind all these recommendations. Learn from it, take advantage of it. Consider that "the first stage is denial." Roll quickly through the denial stage, pull the wheels and hubs off again so you can progress to the discovery stage. Inspection will lead you to the analysis stage. You can postulate and speculate 'til the cows come home. Based on the many accumulated years of knowledge and experience guiding you here, we are telling you what you'll see and why. Do you think that cone and roller you disassembled is the first one I/we have seen like that? Why would we even suggest that inspection do you think? Others already know what's happened, and have dealt with the fringe benefits like the collateral damage to the spindle. And with drastically shortened bearing life that goes with leaving the damaged cup in there with the new rollers and cone.
Don't post back until you've taken the time to remove the hub again and inspect the spindle. Take pictures of the top and bottom areas where the inner bearing rides, and share the pictures. Dime to a donut, the bottom of the spindle will be worn.
While the hub is off, replace both bearings complete. If you've not driven on the new cones in the old cups, they may be OK to put back in. But bearings are cheap, no need to risk further problems for a few dollars.
Do the other side too.