Amsoil Differential Fluid
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Joined: Jan 2006
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From: Southeast PA
Amsoil Differential Fluid
I was going to take my '05 Vet to the dealer for the TSB for rear grinding noise until I read the threads about the noise coming back after a couple thousand miles with GM Fluid.
I just changed mine with Amsoil, and noticed an immediate difference. Now we will have to see if the noise stays away... time will tell! I am impressed so far... hopefully I did not jinx myself.
I just changed mine with Amsoil, and noticed an immediate difference. Now we will have to see if the noise stays away... time will tell! I am impressed so far... hopefully I did not jinx myself.
Melting Slicks
Joined: Oct 2004
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From: CA
GM recently changed to using a double dose of the friction additive when you change the gear oil.
So I did that myself. Will also do some pre-emptive figure eights when the car sits for more then a day.
If all that fails, I'll move on to another brand for the gear oil.
There are enough of us experimenting that over time a winning method or two should become clear.
So I did that myself. Will also do some pre-emptive figure eights when the car sits for more then a day.
If all that fails, I'll move on to another brand for the gear oil.
There are enough of us experimenting that over time a winning method or two should become clear.
Intermediate
Joined: Jan 2007
Posts: 41
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From: Bakersfield California
Just add additive?
My local Mobel 1 Quick Change Service suggested just adding the GM additive to my O7 with 5000 miles, after they saw the state of the lube. They didnt buy any issue of varnish buildup on the disks. I had grinding for the last 2500 miles. They said just more additive is needed in my case. It cost just $13 installed and has worked so far, for the last 2 weeks. I like this oufit because they use pits, no lifting hazard, I can watch them and there is little wait. If the grinding returns, I'll do a $60 Mobil 1 synthetic LS differentiall lube change and supply my own Amsoil synthetic LS additive, available from Amsoil Web site.
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Melting Slicks
Joined: Mar 2001
Posts: 2,117
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From: El Paso TX
I used Amsoil's additive instead of the GM stuff. So far so good with mine. Amazing how quiet the car is after the switch. Now I can just get in and drive without constantly listening for the chatter.
Matt
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Joined: Aug 2000
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From: Central Florida
Here is a lucid explanation of the working of posi-traction, its characteristic chatter, and the role of an additive in quieting the chatter.
AMSOIL Slip-Lock Differential Additive Write-up.
Ranger
AMSOIL Slip-Lock Differential Additive Write-up.
Ranger
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From: Chandler Arizona
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From: King George VA
) which is effectively equivalent to GM fluid and two bottles of GM additive.Note though that in the C5 and other cars I don't recommend any extra additive. I don't use extra additive with this same fluid in my 02 C5 Z06 or my 06 CTS-V.
Race Director
Joined: Aug 2000
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From: Central Florida
^^^ Hey Subdriver.
Most of the C6Z owners in our club continue to have growling diff clutches after the second swap of GM-brand fiuid and then the revised clutch-pack with GM-brand fluid plus two servings of the friction modifier.
I'm considering adding a bottle of the Amsoil Friction Modifier to the existing GM fluid in my diff (first swap done under warranty 5K miles ago). Mine is noisy despite a routine of figure-8s to keep the fluid distributed. A small test.
Ranger
Most of the C6Z owners in our club continue to have growling diff clutches after the second swap of GM-brand fiuid and then the revised clutch-pack with GM-brand fluid plus two servings of the friction modifier.
I'm considering adding a bottle of the Amsoil Friction Modifier to the existing GM fluid in my diff (first swap done under warranty 5K miles ago). Mine is noisy despite a routine of figure-8s to keep the fluid distributed. A small test.
Ranger
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From: King George VA
But... it appears from what I've read that the diff clutch growl is very sensitive to dirty fluid, as well as the afformentioned keeping the fluid in the clutch packs. Most of the threads I've read on this issue seem to indicate that changing the fluid momentarily cures the problem. Using AMSOIL's Severe Gear seems to keep the problem away longer. That may be due to the fluid being better at preventing wear, thus minimizing the particle buildup in the diff, or it may be due to different characteristics of the basestock resulting in the fluid staying in the clutch packs better... or likely some combination of both.
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From: Central Florida
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We have done the same with a few customers also, so far so good, for some time now too.
Amsoil has became our main oils used years ago, and we never looked back.
Le Mans Master
Joined: Feb 2006
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From: Chandler Arizona
One question. I would think that the main reason the chattering goes away with the use of Amzoil and the additive is that it is more slippery (is that a technical term?).
However, if it's more slippery, doesn't that mean that the clutch plates do not grab as well and therefore the Positraction unit doesn't perform as well? Wouldn't it have a tendency to not transfer the torque as much and let the one tire spin more?
Thanks,
Glenn
However, if it's more slippery, doesn't that mean that the clutch plates do not grab as well and therefore the Positraction unit doesn't perform as well? Wouldn't it have a tendency to not transfer the torque as much and let the one tire spin more?
Thanks,
Glenn
Melting Slicks
Joined: Feb 2006
Posts: 2,261
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From: Brentwood CA
I decided to go with Amsoil as so many had tried having the dealer change the oil with the GM additive but the chatter seemed to come back in the majority of the posts. The posts in regards to Amsoil seemed a little more promising. Anyway, I have around 400-500 miles on the car since the change. I'm keeping my fingers crossed that the chatter stays away.