Leakage Evident on Rear Axle
12-06-2001, 01:41 AM
#1
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Thread Starter
Leakage Evident on Rear Axle
Okay, as I am about to investigate a problem that has come up lately, I wonder if anyone out there has experienced the same??
Recently I have noticed a black grease type substance that seems to be coming out of the axle/hub on the left rear of my 964. It splatters all over the inside of the wheel and runs down the five "spokes", running outward on the wheel, of course.
The only thing I could imagine is that when I upgraded to four piston calipers in the rear, I did NOT reduce the brake bias pressure to the rear and attended two DE events. Both events yielded evidence that the rear brakes were getting VERY hot, also, the ABS was kicking in quite a bit. I do remember wiping some of that black grease off at one of the events...dismissing it as anti-seize compound that I have used on the threads.
It has become apparent that this is not anti-seize compound.
Since changing out the brake bias valve to a lower rating, 45 bar to 33 bar, I have not experienced the ABS kicking in too often, nor are the rear brakes wearing prematurely/getting too hot...so, that problem fixed.
Is is possible that I "cooked" the bearing seal in the rear?? This would allow grease from the bearing to leak out?? Otherwise, I'm lost!
Recently I have noticed a black grease type substance that seems to be coming out of the axle/hub on the left rear of my 964. It splatters all over the inside of the wheel and runs down the five "spokes", running outward on the wheel, of course.
The only thing I could imagine is that when I upgraded to four piston calipers in the rear, I did NOT reduce the brake bias pressure to the rear and attended two DE events. Both events yielded evidence that the rear brakes were getting VERY hot, also, the ABS was kicking in quite a bit. I do remember wiping some of that black grease off at one of the events...dismissing it as anti-seize compound that I have used on the threads.
It has become apparent that this is not anti-seize compound.
Since changing out the brake bias valve to a lower rating, 45 bar to 33 bar, I have not experienced the ABS kicking in too often, nor are the rear brakes wearing prematurely/getting too hot...so, that problem fixed.
Is is possible that I "cooked" the bearing seal in the rear?? This would allow grease from the bearing to leak out?? Otherwise, I'm lost!
12-06-2001, 02:41 AM
#2
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Jeff;
It most likely is your constant velocity joint boot, it's cracked or has a small hole in it. When your car is in motion the centrifical force flings it outward.
It most likely is your constant velocity joint boot, it's cracked or has a small hole in it. When your car is in motion the centrifical force flings it outward.
12-06-2001, 06:57 AM
#3
Race Car
Thread Starter
Kevin, I would agree with you...but the leakage isn't anywhere near that far inboard.
When I have my wheel off, there is a black grease like substance that looks like it's emminating from the center of the hub, between the lugs.
When I have my wheel off, there is a black grease like substance that looks like it's emminating from the center of the hub, between the lugs.
12-06-2001, 07:03 AM
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Dear Jeff,
You have considered (in your first post) that this may be wheel bearing grease. If the brakes are getting hot, this will heat the hub and original grease maybe melting and flowing out. Not an unknown problem. Maybe the wqheel bearing has been over packed and the excess is being blown out because it is now more fluid. I believe this is a wheel bearing related problem,
Ciao,
Adrian
911C4
You have considered (in your first post) that this may be wheel bearing grease. If the brakes are getting hot, this will heat the hub and original grease maybe melting and flowing out. Not an unknown problem. Maybe the wqheel bearing has been over packed and the excess is being blown out because it is now more fluid. I believe this is a wheel bearing related problem,
Ciao,
Adrian
911C4
12-06-2001, 10:43 AM
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Having replaced two left rear wheel bearings this year (one in May and one in November), I had the same symptons, Jeff. Except on the first one I didn't do anything about it and it let loose on track at 90+mph which caused about $1400 worth of damage (not body). This second time I noticed the bearing loose as I was prepping the car for a race. Looked inside and saw that grease coming out. Now my mechanic is trying to figure out why the second bearing went up. I had only about 12 track days on it. The original bearing got over 150 days on it before it let loose.
12-07-2001, 12:14 AM
#6
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Thread Starter
Excellent! That is the answer I was looking for, thanks Manny and Adrian...that was the only thing I could guess it was.
Has anybody had experience with replacing these themselves?? I have a friend that has an older 911S and I know it was a bitch replacing his...wondering if the 964 is that difficult.
Has anybody had experience with replacing these themselves?? I have a friend that has an older 911S and I know it was a bitch replacing his...wondering if the 964 is that difficult.
