Rumbling noise: LSD?
08-23-2010, 12:50 PM
#16
Nordschleife Master
Whomever is giving out that advice needs to have their wrenches taken away...
09-07-2010, 07:33 PM
#17
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I took my mechanic for a ride in the car: of course it did not make that sound on that day, but we could hear a humming sound at idle, that he identified as coming likely from the hydraulic fluid pump. I asked him to check the fluid level: he had to add half a quart! Unless there is a leak, the guy (not my usual mechanic) who did the annual maintenance last year did not bother to check the hydraulic fluid; rascal!
Since then, I have not heard that noise again. It's weird that it was making that noise on left turns, but not on right turns. Anyway, for now at least I consider the cause of the noise identified, and the problem fixed. The annual maintenance is due next month, and I will have both the tranny and the LSD fluids replaced. And in future, I'll check myself the hydraulic fluid level.
Thanks to all the guys who posted with their suggestions!
Since then, I have not heard that noise again. It's weird that it was making that noise on left turns, but not on right turns. Anyway, for now at least I consider the cause of the noise identified, and the problem fixed. The annual maintenance is due next month, and I will have both the tranny and the LSD fluids replaced. And in future, I'll check myself the hydraulic fluid level.
Thanks to all the guys who posted with their suggestions!
09-11-2010, 05:48 PM
#18
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I hope he remembered to pump the clutch accumulator down before he filled it, otherwise it will be overfilled and make a big mess. (Don't ask how I know!)
09-12-2010, 11:39 PM
#20
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I had the same "exact" symptoms. I'm fairly certain it's your clutch accumulator and/or slave master. Have you ever experienced issues with a stiff clutch? Without getting these checked and filling the reservoir in the rear engine compartment, it may end up overflowing and leaking in your trunk area up front.
09-14-2010, 01:53 PM
#21
Nordschleife Master
https://rennlist.com/forums/997-gt2-...sd-buster.html
Hell, when you use ridiculously long service intervals on your oil changes and wear out your gearbox prematurely, it's good for my business. Go right ahead and neglect your car if you wish...
09-14-2010, 11:30 PM
#22
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911/Q45: thank you for your input, as I don't think that he pumped the accumulator down!
NCP, you might just have hit right on it! I bought the car with 30 k miles on it, and from day one, the clutch has always been very heavy, but I assumed that this was just the way it is, as I had never driven a 911 before buying this one. Prior to buying the car, we had a look at it, and there was oil under the carpet in the front boot, like oil had been sprayed.
We did ask about it, and the seller said that he had placed a quart of motor oil there, that had leaked. We did not believe it, as it was not consistent with a spray, but no one could find the cause of it; the car always worked fine, and I have not had any trouble with it, other than the infamous fogging after a lay-up.
The car is back in the workshop as the bushing of the angular joint ball cup of the shift linkage disintegrated, resulting in a non-operating gear shift (happened when driving out of my garage: God does seem to protect the innocents); so in addition to replacing the angular joint, changing the tranny and LSD fluids, and having the annual maintenance done, I am going to ask the mechanic to check the clutch accumulator and the "slave master" [do you mean the clutch master cylinder - 993.423.171.50.M33- or (heavens-forbid) the slave cylinder 993.116.237.52.M100?]. By the way, would that oil spray be consistent with the clutch accumulator, or with the other part, or could it be either (or both?)?
Many thanks for your input, as I think you have helped me solve that oil spray riddle that has been haunting me ever since I bought the car.
NCP, you might just have hit right on it! I bought the car with 30 k miles on it, and from day one, the clutch has always been very heavy, but I assumed that this was just the way it is, as I had never driven a 911 before buying this one. Prior to buying the car, we had a look at it, and there was oil under the carpet in the front boot, like oil had been sprayed.
We did ask about it, and the seller said that he had placed a quart of motor oil there, that had leaked. We did not believe it, as it was not consistent with a spray, but no one could find the cause of it; the car always worked fine, and I have not had any trouble with it, other than the infamous fogging after a lay-up.
The car is back in the workshop as the bushing of the angular joint ball cup of the shift linkage disintegrated, resulting in a non-operating gear shift (happened when driving out of my garage: God does seem to protect the innocents); so in addition to replacing the angular joint, changing the tranny and LSD fluids, and having the annual maintenance done, I am going to ask the mechanic to check the clutch accumulator and the "slave master" [do you mean the clutch master cylinder - 993.423.171.50.M33- or (heavens-forbid) the slave cylinder 993.116.237.52.M100?]. By the way, would that oil spray be consistent with the clutch accumulator, or with the other part, or could it be either (or both?)?
Many thanks for your input, as I think you have helped me solve that oil spray riddle that has been haunting me ever since I bought the car.
Last edited by 993Biturbo430; 09-15-2010 at 07:13 AM.
09-15-2010, 04:21 AM
#23
Rennlist Member
Biturbo 430, got your email. To the contrary, if it's a stock clutch, it should actually be on the light side. Based on your explanation, I'm certain its your accumulator and likely the slave cylinder. If the slave is not a problem now, it will become an issue once you replace the accumulator, as the new accumulator seems to place a lot of increased pressure on the old slave which quickly goes bad soon after. So standard protocol is to replace both regardless of whether you think its one or the other. It isn't cheap or easy to get in there, but whatever you do, don't do one without doing the other. I made the mistake of not listening to the advice of those much wiser than me when my accumulator went bad and replaced only the accumulator on my wrenches advice. A year later, I was back in there replacing the slave. Hope that helps.
