Differental Additive
Le Mans Master
Joined: Feb 2014
Posts: 5,463
Likes: 1,138
From: Chino CA
Just responding to your statement that made it seem like there are a lot of different opinions and variations of this repair when there is a definitive answer that has been proven to take care of the problem. I was just trying to make sure the OP knew that this is an easy fix if done properly. His dealer is wrong. No additives to buy or add if the proper fluid is used. I would be worried about a Service Advisor or Tech that did not know this by now.
Last edited by HBsurfer; Nov 21, 2014 at 06:02 PM.
Burning Brakes
Joined: Jun 2013
Posts: 867
Likes: 26
From: SW Ohio
Hope this isn't a dumb question or one that has been tossed about in other threads ad naseum, but for a car that isn't a daily driver but has 5K-6K a year put on the odo between Apr and Dec, is there ANY BENEFIT gained by occasionally--say 1x or 2x per year--doing the figure 8s to evenly distribute the fluid to the clutch packs WITHOUT doing a fluid change? Obviously it won't hurt anything, but will it keep the differential clutches from doing the dreaded clunking as the car ages?
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
Hope this isn't a dumb question or one that has been tossed about in other threads ad naseum, but for a car that isn't a daily driver but has 5K-6K a year put on the odo between Apr and Dec, is there ANY BENEFIT gained by occasionally--say 1x or 2x per year--doing the figure 8s to evenly distribute the fluid to the clutch packs WITHOUT doing a fluid change? Obviously it won't hurt anything, but will it keep the differential clutches from doing the dreaded clunking as the car ages?
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Hope this isn't a dumb question or one that has been tossed about in other threads ad naseum, but for a car that isn't a daily driver but has 5K-6K a year put on the odo between Apr and Dec, is there ANY BENEFIT gained by occasionally--say 1x or 2x per year--doing the figure 8s to evenly distribute the fluid to the clutch packs WITHOUT doing a fluid change? Obviously it won't hurt anything, but will it keep the differential clutches from doing the dreaded clunking as the car ages?
You can still do the figure 8's and have some fun if you want anyway.
Le Mans Master
Joined: Feb 2007
Posts: 8,514
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From: Currently somewhere in IL,IN,KY,TN,MO,AR,MS,AL, or FL
The only reason the figure 8 technique exists, is when a car that had the old 2-part fluid drained and the newer all-in-one fluid installed, that the service tech did the procedure prior to giving the car back to the customer. That assured the fluid was fully integrated and had resolved the chatter issue, so the customer would have immediate satisfaction rather than having to drive several miles first. Your standard everyday driving continues to move the fluid in the correct method.
You can still do the figure 8's and have some fun if you want anyway.
You can still do the figure 8's and have some fun if you want anyway.
The figure 8's are to force the old fluid out and new fluid into the packs. Once there is new fluid inside the packs there is no need to keep mixing. The old additive would break down inside the packs so doing figure 8's MIGHT help for a short time if that was all you had in there but the new fluid with included additive doesn't seem to break down.OP, you need to find a dealer who knows something about C6 maintenance. It's been at LEAST 4 years since additive was added. I'm wondering if GM even still sells the additive or if they have to find it on the back of a dusty shelf somewhere. In any case, your dealer is at least ignorant if not stupid.
Melting Slicks
Joined: Apr 2012
Posts: 2,566
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St Jude Donor '14
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
The change happened mid 2008 model year. Mine was an 2007 August build and I needed to update the fluid. Others that had a 2008 built later already had the newer fluid from the factory.
So more like 6 years for the additive.
So more like 6 years for the additive.
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Thread Starter
Advanced
Joined: May 2014
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I'm not as confused as I was, but still in a little fog! More on the dealer who wanted to put additive in my differential. First I was told that my car didn't have a limited slip diff and only needed gear oil. Told me that only special order cars has the limited slip diff. I insisted that my car did have the limited slip axle. He then went and huddled with the parts guy and came back and told me that they would need to order the additive. Further more since my car had the limited slip axle it was a trans axle and would require that the pan be removed in order for the fluid to be changed. He then quoted me a $350 price. I said I would get back to him on that! Thanks for the clarification on the fluid and change. I think I will change it myself and never go back to this dealer again! JDA
Drifting
Joined: Jun 2008
Posts: 1,746
Likes: 35
From: Jupiter Fl
I'm not as confused as I was, but still in a little fog! More on the dealer who wanted to put additive in my differential. First I was told that my car didn't have a limited slip diff and only needed gear oil. Told me that only special order cars has the limited slip diff. I insisted that my car did have the limited slip axle. He then went and huddled with the parts guy and came back and told me that they would need to order the additive. Further more since my car had the limited slip axle it was a trans axle and would require that the pan be removed in order for the fluid to be changed. He then quoted me a $350 price. I said I would get back to him on that! Thanks for the clarification on the fluid and change. I think I will change it myself and never go back to this dealer again! JDA
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
I'm not as confused as I was, but still in a little fog! More on the dealer who wanted to put additive in my differential. First I was told that my car didn't have a limited slip diff and only needed gear oil. Told me that only special order cars has the limited slip diff. I insisted that my car did have the limited slip axle. He then went and huddled with the parts guy and came back and told me that they would need to order the additive. Further more since my car had the limited slip axle it was a trans axle and would require that the pan be removed in order for the fluid to be changed. He then quoted me a $350 price. I said I would get back to him on that! Thanks for the clarification on the fluid and change. I think I will change it myself and never go back to this dealer again! JDA
Le Mans Master
Joined: Oct 2012
Posts: 5,910
Likes: 49
From: CA
St. Jude Donor '17
So where do I stand with an 06 with 71K on it and have never changed the diff oil? I've owned cars all my life that have gone over 100K and never changed their diff oil either. What makes it seemingly so imperative?
Team Owner
Joined: Sep 2000
Posts: 25,009
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From: Far NW 'burbs of Chicago
St. Jude Donor '13
Before the new fluid became available, it was somewhat common for the dif to start chattering every 20k-50k miles, so changing the fluid on a schedule would often get the fluid changed in time to prevent the chatter.
We changed ours at about 8k to get the initial junk out, then again at 50k and sent a sample to Blackstone Labs. They said both the oil and the dif were in excellent condition and could easily go further.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
That's a real "WOW!!!" rcjays. I believe Ft. Morgan has gotten it all: a lack of knowledge on the part of that dealership. cclive summarized it well: they got nothing right at that dealership.
OP, if you want to do a service to your fellow owners, you might just tell us the name of this great dealership so some other Corvetteer avoids it like the plague!
OP, if you want to do a service to your fellow owners, you might just tell us the name of this great dealership so some other Corvetteer avoids it like the plague!
Melting Slicks
Joined: Apr 2012
Posts: 2,566
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St Jude Donor '14
Le Mans Master
Joined: Oct 2012
Posts: 6,391
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From: South Dakota
The Z51 option requires almost 3 quarts? I don't know, just asking. I changed out my diff fluid last summer (non Z51) and drained out almost exactly 2 quarts, and added back right at 2 quarts.
Safety Car
Joined: Jan 2011
Posts: 4,959
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Mine was chattering at 10-K. Think if one researches they will find that some of them would chatter before they got home from buying the car. Hence the issues sprouting up about the gear oil lube needing to be re-vised.