CV axle problem?
#1
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CV axle problem?
Has anyone experienced this?
NA axle replaced w/Turbo axle new OE part in 2007 and has about 2500 track only miles now. Vent hole spewing grease all over the wheel. No funny noises or obvious abnormalities, no excessive play, or binding on ispection of axle, or bearing. Axle boots look new no leaks. Drivers side only. I have never seen this. I am told this is not unusual??? Could this be a problem with cv joint heating up too much? Advice? Ignore and just clean off.... Of course this will stop when there is no more grease left in the joint! Should I take off boot and repack cv joint now?
Thanks
NA axle replaced w/Turbo axle new OE part in 2007 and has about 2500 track only miles now. Vent hole spewing grease all over the wheel. No funny noises or obvious abnormalities, no excessive play, or binding on ispection of axle, or bearing. Axle boots look new no leaks. Drivers side only. I have never seen this. I am told this is not unusual??? Could this be a problem with cv joint heating up too much? Advice? Ignore and just clean off.... Of course this will stop when there is no more grease left in the joint! Should I take off boot and repack cv joint now?
Thanks
Last edited by mbb993; 06-30-2009 at 11:34 PM.
#3
Nordschleife Master
The grease used in the replacement axles is not durable for track usage. What you see is not uncommon on any car that is tracked heavily. What you are seeing is the grease exceeding its rated temperature and once you do this, your CV joint will show wear on the races if you were to take it apart. I usually buy a new axle, take it apart, replace the grease with racing grease from Krytox or Neo and reassemble the axle. I've had good success with that method and joint longevity.
#4
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Geoffrey beat me to it. The stock grease can last as little as 4 hours of track use before it fails and you end up ruining your CV. I now have new axles rebuilt and the grease replaced before use and always carry a spare set. If your car is lowered substantially and the axle geometry gets off, it gets exponentially worse dye to the additional heat generated.
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The grease used in the replacement axles is not durable for track usage. What you see is not uncommon on any car that is tracked heavily. What you are seeing is the grease exceeding its rated temperature and once you do this, your CV joint will show wear on the races if you were to take it apart. I usually buy a new axle, take it apart, replace the grease with racing grease from Krytox or Neo and reassemble the axle. I've had good success with that method and joint longevity.
Geoffrey beat me to it. The stock grease can last as little as 4 hours of track use before it fails and you end up ruining your CV. I now have new axles rebuilt and the grease replaced before use and always carry a spare set. If your car is lowered substantially and the axle geometry gets off, it gets exponentially worse dye to the additional heat generated.
Thanks for the help guys. Time for me to get to work!
#6
Race Car
The grease used in the replacement axles is not durable for track usage. What you see is not uncommon on any car that is tracked heavily. What you are seeing is the grease exceeding its rated temperature and once you do this, your CV joint will show wear on the races if you were to take it apart. I usually buy a new axle, take it apart, replace the grease with racing grease from Krytox or Neo and reassemble the axle. I've had good success with that method and joint longevity.
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Geoffrey beat me to it. The stock grease can last as little as 4 hours of track use before it fails and you end up ruining your CV. I now have new axles rebuilt and the grease replaced before use and always carry a spare set. If your car is lowered substantially and the axle geometry gets off, it gets exponentially worse dye to the additional heat generated.
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These are interesting comments. I don't race but I do track my 4S and have never had any issues with CV grease (I can't seem to keep inner CV bolts in the joint on the drivers side). I use the standard issue German CV grease that I get with replacement boots.
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Geoffrey beat me to it. The stock grease can last as little as 4 hours of track use before it fails and you end up ruining your CV. I now have new axles rebuilt and the grease replaced before use and always carry a spare set. If your car is lowered substantially and the axle geometry gets off, it gets exponentially worse dye to the additional heat generated.
__________________
These are interesting comments. I don't race but I do track my 4S and have never had any issues with CV grease (I can't seem to keep inner CV bolts in the joint on the drivers side). I use the standard issue German CV grease that I get with replacement boots.
#7
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Have you ever taken the CV apart and looked for how the grease has held up? In my case, after 5 hours there was no 'grease' left, just some dried, cracked crud. My car is lowered and has a less than optimum axle angle (not 90 degrees) and this likely leads to more than normal heating/wear. We have tried to address this without compromising the roll center/geometry and it has helped. My axles are now lubricated with Krytox to get the most life out of them. You should try Neo first if you have this problem though, it's cheaper and a lot less toxic.
No offense, but a 4-hour enduro or 30-minute sprint race race is likely a bit harder on the car than a 30 minute-DE. While we might not see issues in a DE where the car might not be pushed as hard, it is an issue when racing. The other 964's and cars using the same axles in my race class have similar problems.
No offense, but a 4-hour enduro or 30-minute sprint race race is likely a bit harder on the car than a 30 minute-DE. While we might not see issues in a DE where the car might not be pushed as hard, it is an issue when racing. The other 964's and cars using the same axles in my race class have similar problems.
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#8
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Have you ever taken the CV apart and looked for how the grease has held up? In my case, after 5 hours there was no 'grease' left, just some dried, cracked crud. My car is lowered and has a less than optimum axle angle (not 90 degrees) and this likely leads to more than normal heating/wear. We have tried to address this without compromising the roll center/geometry and it has helped. My axles are now lubricated with Krytox to get the most life out of them. You should try Neo first if you have this problem though, it's cheaper and a lot less toxic.
No offense, but a 4-hour enduro or 30-minute sprint race race is likely a bit harder on the car than a 30 minute-DE. While we might not see issues in a DE where the car might not be pushed as hard, it is an issue when racing. The other 964's and cars using the same axles in my race class have similar problems.
No offense, but a 4-hour enduro or 30-minute sprint race race is likely a bit harder on the car than a 30 minute-DE. While we might not see issues in a DE where the car might not be pushed as hard, it is an issue when racing. The other 964's and cars using the same axles in my race class have similar problems.
If this is the case it's possible that one would be unaware of this problem since there is no way for the broken down grease to be expelled unless the rubber boot were compromised.
Last edited by mbb993; 07-02-2009 at 07:57 AM.
#9
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#12
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Can't comment on a true venting, but my axles are hollow.
Tom, I'll agree on the enduro......but you've never seen me drive a DE I'm no back marker I would think with the heat of the south, and the pounding the car gets, if the grease was to completely break down, it would in that amount of time and under those conditions. I'm running RS height +/- (FWIW)
Having worked for a CV rebuilder many years ago, we saw axles come in all the time with "liquid" for grease. Occasionally we saw "chunks" but thats usually due to water infiltrating the boot and remaining there, which solidified the grease.
Tom, I'll agree on the enduro......but you've never seen me drive a DE I'm no back marker I would think with the heat of the south, and the pounding the car gets, if the grease was to completely break down, it would in that amount of time and under those conditions. I'm running RS height +/- (FWIW)
Having worked for a CV rebuilder many years ago, we saw axles come in all the time with "liquid" for grease. Occasionally we saw "chunks" but thats usually due to water infiltrating the boot and remaining there, which solidified the grease.