Changing diff fluid
Instructor
Joined: Sep 2009
Posts: 155
Likes: 0
From: Indianapolis IN
The first time you change most of the fluids (especially motor oil and transmission), they typically don't look good. Lots of fine metal particles. My diff actually didn't look too bad compared with my motor oil and transmission. Nonetheless, I switched my motor oil, transmission, and diff to Redline. Didn't really notice much of a differenence with the motor oil, and I just did the diff so I can't comment on that yet. But the transmission now shifts so much smoother. My Z06 use to be a bit notchy shiftting when cold, and with Redline it is totally smooth. Good stuff.
Team Owner
Joined: Sep 2000
Posts: 25,022
Likes: 2,714
From: Far NW 'burbs of Chicago
St. Jude Donor '13
That doesn't explain why the car started chattering...
The oil might still have life left in it, but if your car is chattering maybe you should replace the oil. As in my case.
I personally would rather replace the oil for 40.00 when the car gets noisy so I can drive a quiet car instead of paying 40.00 to get my oil tested and still be driving a noisy car because some lab tech said the oil was still fine.
If I had a car that was not making noise, I would still replace the oil at regular intervals just to help keep the differential somewhat clean and avoid any unneeded wear because I was too cheap to replace my fluids before they are 100% worn out.
But you keep paying the laboratory, they really like your money.
The oil might still have life left in it, but if your car is chattering maybe you should replace the oil. As in my case.
I personally would rather replace the oil for 40.00 when the car gets noisy so I can drive a quiet car instead of paying 40.00 to get my oil tested and still be driving a noisy car because some lab tech said the oil was still fine.
If I had a car that was not making noise, I would still replace the oil at regular intervals just to help keep the differential somewhat clean and avoid any unneeded wear because I was too cheap to replace my fluids before they are 100% worn out.
But you keep paying the laboratory, they really like your money.
If our car developed the chatter at any time, I would immediately have the fluid changed.
I was only trying to second ELP_JC's post that once the initial crud has been removed, then the next fill can go for a long time- if you don't have chatter. The lab results give us some idea of how long the fluid can go before it is "100% worn out."
Melting Slicks
Joined: Jun 2007
Posts: 2,673
Likes: 9
From: Upstate New York
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Red,
If you do opt for the AMSOIL fluids, this is what you'll need for tranny (assuming 6 spd manual) and diff (and yes, all C6 models have limited slip diffs):
AMSOIL Torque-Drive Synthetic Automatic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
Quantities would be 1 gal Torque Drive ATF, 2 qts Severe Gear 75w90, and one bottle (4 oz) of Slip Lock Additive.
Have fun in October!
More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.
If you do opt for the AMSOIL fluids, this is what you'll need for tranny (assuming 6 spd manual) and diff (and yes, all C6 models have limited slip diffs):
AMSOIL Torque-Drive Synthetic Automatic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
Quantities would be 1 gal Torque Drive ATF, 2 qts Severe Gear 75w90, and one bottle (4 oz) of Slip Lock Additive.
Have fun in October!
More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.
__________________
C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
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Verdad Gallardo
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Red,
If you do opt for the AMSOIL fluids, this is what you'll need for tranny (assuming 6 spd manual) and diff (and yes, all C6 models have limited slip diffs):
AMSOIL Torque-Drive Synthetic Automatic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
Quantities would be 1 gal Torque Drive ATF, 2 qts Severe Gear 75w90, and one bottle (4 oz) of Slip Lock Additive.
Have fun in October!
More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.
If you do opt for the AMSOIL fluids, this is what you'll need for tranny (assuming 6 spd manual) and diff (and yes, all C6 models have limited slip diffs):
AMSOIL Torque-Drive Synthetic Automatic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
AMSOIL Slip-Lock Differential Additive (Product Code ADATB)
Quantities would be 1 gal Torque Drive ATF, 2 qts Severe Gear 75w90, and one bottle (4 oz) of Slip Lock Additive.
Have fun in October!
More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.
on a 2005 Corvette with 4 spd. auto trans?
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Dating back many years ago now, but in about 2007 I discussed these two fluids with AMSOIL's lead drive train engineer and how they were used in GM manual transmission fluid applications. Not long after that discussion, they updated their online application guide to indicate the Torque Drive ATF as their "primary" recommendation and the Universal ATF (now call Signature Series Multi-Vehicle ATF) as the "secondary" recommendation for manual transmissions.
I think the main difference is the Torque Drive ATF has no viscosity modifiers and won't shear down in viscosity despite the shear forces on the fluid in the transmission (not that the Multi-Vehicles ATF is prone to viscosity shear down either, but it does have some viscosity improvers).
I've been using the Torque Drive ATF in my T56 at the track since 2007 and recommend it for all GM Tremec applications (as AMSOIL does).
For automatics, the larger viscosity spread the viscosity improvers of the Multi-vehicle ATF may lead to AMSOIL's recommendation swapping, and for ATFs, I'd use the Signature Series Multi-Vehicle ATF (product ATFQT).
Last edited by C66 Racing; Aug 26, 2013 at 08:07 PM.
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Not too much - both are Dexron III fluids.
Dating back many years ago now, but in about 2007 I discussed these two fluids with AMSOIL's lead drive train engineer and how they were used in GM manual transmission fluid applications. Not long after that discussion, they updated their online application guide to indicate the Torque Drive ATF as their "primary" recommendation and the Universal ATF (now call Signature Series Multi-Vehicle ATF) as the "secondary" recommendation for manual transmissions.
I think the main difference is the Torque Drive ATF has no viscosity modifiers and won't shear down in viscosity despite the shear forces on the fluid in the transmission (not that the Multi-Vehicles ATF is prone to viscosity shear down either, but it does have some viscosity improvers).
I've been using the Torque Drive ATF in my T56 at the track since 2007 and recommend it for all GM Tremec applications (as AMSOIL does).
For automatics, the larger viscosity spread the viscosity improvers of the Multi-vehicle ATF may lead to AMSOIL's recommendation swapping, and for ATFs, I'd use the Signature Series Multi-Vehicle ATF (product ATFQT).
Dating back many years ago now, but in about 2007 I discussed these two fluids with AMSOIL's lead drive train engineer and how they were used in GM manual transmission fluid applications. Not long after that discussion, they updated their online application guide to indicate the Torque Drive ATF as their "primary" recommendation and the Universal ATF (now call Signature Series Multi-Vehicle ATF) as the "secondary" recommendation for manual transmissions.
I think the main difference is the Torque Drive ATF has no viscosity modifiers and won't shear down in viscosity despite the shear forces on the fluid in the transmission (not that the Multi-Vehicles ATF is prone to viscosity shear down either, but it does have some viscosity improvers).
I've been using the Torque Drive ATF in my T56 at the track since 2007 and recommend it for all GM Tremec applications (as AMSOIL does).
For automatics, the larger viscosity spread the viscosity improvers of the Multi-vehicle ATF may lead to AMSOIL's recommendation swapping, and for ATFs, I'd use the Signature Series Multi-Vehicle ATF (product ATFQT).