Mobil One Synthetic fluids vs. Redline Synthetic fluids

[abc]

For your rear end differential and your automatic transmission which fluid would you choose to use and why?
The 75W/90 that comes in the Corvette is already a synthetic fluid but I'm not sure of which brand.
The DEXRON III (H) which is not synthetic comes in the A-4. I believe The new DEXRON IV can also be used in the A-4 but I don't know if it is synthetic.
So would you switch to a synthetic fluid on the A-4? If so which brand? Same goes for the rear end 75W/90 which brand?

 

[hddeuce]

I'm not sure this will help but I use RedLine Shockproof Heavy in my harley 5 speed transmission and it is FAN-TAS-TIC compared with the other synthetice I have tried - so I would chose Redline, at least for the differential.

 

[red01]

Why not use what the Corvette engineers recommend?

 

[abc]

I'm not sure this will help but I use RedLine Shockproof Heavy in my harley 5 speed transmission and it is FAN-TAS-TIC compared with the other synthetice I have tried - so I would chose Redline, at least for the differential.

I am using Redline on my other car in the 5 spd. manual and the rear end differential. Can't tell any difference with rear end but with 5 spd. it made a day and night difference shifting is like a piece of cake real smooth made a difference between selling the car and keeping it.
I may use the Amsoil 75W/90 Severe Gear Oil on the rear end differential of C-6 Corvette. I keep hearing that Amsoil is the BEST.

 

[abc]

Why not use what the Corvette engineers recommend?

Because what they recommend is not synthetic for the A-4 transmission.
For the automatic transmission on the 2005 Corvette that would be now DEXRON IV and I don't think it is synthetic.
Redline makes a D4ATF that is suppose to work.
Amsoil has not come out with a comparable ATF yet for this application.
The rear differential uses a GM synthetic 75w/90 gear oil in it. I don't know which company makes the rear end fluid for GM, but I would think AMSOIL would be the best.

 

[c4c5specialist]

Hi there,
Dexron 6 is a partial synthetic, NOT A FULL synthetic.
The fact is that in the A4, you will NOT see a real change in performance over a standard Dexron 6 or the synthetic.
And, in order to keep contamination, you will need to change the fluid.
As far as the rest, there is NO confirmed data to indicate that any synthetic fluid in the A4 helps the longevity or shifting smoothness.
Rear end lubricant, GM or Mobil, both meets the exact same specification.
Allthebest, c4c5

 

[abc]

Preventative maintenance on 2005 C-6 rear end and A-4 trans

Hi there,
Dexron 6 is a partial synthetic, NOT A FULL synthetic.
The fact is that in the A4, you will NOT see a real change in performance over a standard Dexron 6 or the synthetic.
And, in order to keep contamination, you will need to change the fluid.
As far as the rest, there is NO confirmed data to indicate that any synthetic fluid in the A4 helps the longevity or shifting smoothness.
Rear end lubricant, GM or Mobil, both meets the exact same specification.
Allthebest, c4c5

Keep in mind I don't track this car it is street driven and has 11,200 miles.
I Never heard of Dexron 6 Do you mean Dexron IV is a partial synthetic?
Now is it true and I know you are qualified to answer this, Should both automatic transmission and the rear end differential fluids be changed once car is broken in to remove those metal shavings?
It would be like the 1,000 mile oil change to rid the metal shavings in engine.
Would you change both fluids in rear end and auto transmission?

Now I understand that the DEXRON IV is what dealership will put in auto trans now as the DEXRON IV replaced the DEXRON III (H) and is suppose to be a better fluid and longer lasting fluid 160,000 miles.
Is the Redline ATF D4 synthetic fluid a better fluid than the DEXRON IV? Which one would you use and why?

In my 2005 manual it says to do an auto transmission service only if there are no leaks. :confused
Then it goes on to say change ATF fluid and filter at 50,000 miles for severe service or at 100,000 for regular service.:confused
Dealership tells me to do auto transmission service flush at 25,000.:confused
Which one is correct?

For rear differential the 2005 manual states that there is no need to change this 75w/90 synthetic fluid unless there is a leak. :confused
I was also told by a GM rep that the rear end differential fluid that comes in Corvette is life long fluid?:confused
Who is correct here as i have never heard of this before.

Also is Amsoil synthetic 75W/90 Severe Gear Fluid for rear end superior to whatever 75W/90 synthetic fluid GM uses?
What does GM use Mobil One for rear end too?

Lots of questions but I appreciate your knowledge and information on this as I am getting different information on the preventative maintenance of these 2 components.

 

[Norseman]

Fluid

IMHO it would just make sense to use what GM recommends. That way you preserve your warranty. I think they know what is best for their cars.

 

[abc]

IMHO it would just make sense to use what GM recommends. That way you preserve your warranty. I think they know what is best for their cars.

What does GM use for the 75w/90 synthetic gear oil for rear end? Mobil One?
Auto trans is DEXRON IV which is semi-synthetic?

 

[abc]

IMHO it would just make sense to use what GM recommends. That way you preserve your warranty. I think they know what is best for their cars.

In the 2005 owners manual it recommends that you don't change fluids on rear end or auto trans unless there is a leak.
Then it goes on to state change auto trans and filter at 50,000 for severe service or 100,000 miles.
Rear end differential is suppose to be life long.
I find all of this hard to believe.:confused
Especially since the transmission and differential are located near the exhaust system. They are all packed in together so there is alot of heat down there with little space for cooling so I would think getting the best fluids would be the best or changing them alot more often but only if NECESSARY as it becomes too much work

 

[Norseman]

Fluids

If you can afford it let them change it a often as you think is necessary to give yourself piece of mind. I run Mobile-1 in all my cars and motorcycles and use OEM's fluids for the diff on my cars and shaft drive on my bike.

 

[abc]

If you can afford it let them change it a often as you think is necessary to give yourself piece of mind. I run Mobile-1 in all my cars and motorcycles and use OEM's fluids for the diff on my cars and shaft drive on my bike.

So in your eyes Mobil One is as good as any other synthetic oil like Amsoil, Redline, Castrol Synthec, and Royal Purple?
It's not the brand of oil but the frequency of how often you change it whether transmission or rear end differential?

 

[Norseman]

Oil

I love Mobil-1. It's the best, it's a slam dunk.

 

[abc]

I love Mobil-1. It's the best, it's a slam dunk.

It is easier to find and the lowest price of the other synthetics like Amsoil or Redline.

 

[abc]

If you can afford it let them change it a often as you think is necessary to give yourself piece of mind. I run Mobile-1 in all my cars and motorcycles and use OEM's fluids for the diff on my cars and shaft drive on my bike.

Then how often do you change the fluid in the rear end? Also same question for transmission?
You can be a little different than others and use Amsoil.:L

 

[c4c5specialist]

Keep in mind I don't track this car it is street driven and has 11,200 miles.
I Never heard of Dexron 6 Do you mean Dexron IV is a partial synthetic?

No, I mean Dexron 6, this fluid supercedes Dexron 3 and 3H. Yes, its is a partial synthetic lubricant.

Now is it true and I know you are qualified to answer this, Should both automatic transmission and the rear end differential fluids be changed once car is broken in to remove those metal shavings?

Honestly, No, I wouldnt change either. Differential maybe at 15000, only because of the friction modifier possibly, NOT because of metal shavings. There is a magnet inside both transmission and differential.

It would be like the 1,000 mile oil change to rid the metal shavings in engine.
Would you change both fluids in rear end and auto transmission?

It could take as much as 10000 miles for the engine to totally break in, due to the usage of Mobil 1 from the factory.

Now I understand that the DEXRON IV is what dealership will put in auto trans now as the DEXRON IV replaced the DEXRON III (H) and is suppose to be a better fluid and longer lasting fluid 160,000 miles.
Is the Redline ATF D4 synthetic fluid a better fluid than the DEXRON IV? Which one would you use and why?

Redline D4ATF is a full synthetic and the only real benefit is the frictional modifier package, which increases the coefficient of friction in the syncronizer cone area. This enables smoother shifting in c5 manual transmissions, althought I have not yet seen a benefit in c6, due to revised syncronizer design.

In my 2005 manual it says to do an auto transmission service only if there are no leaks. :confused

Sometimes, exchanging the fluid will create a larger leak.

Then it goes on to say change ATF fluid and filter at 50,000 miles for severe service or at 100,000 for regular service.:confused

This all depends on your driving style.

Dealership tells me to do auto transmission service flush at 25,000.:confused
Which one is correct?

Correct service intervals are completely BASED on your driving conditions. NOTHING ELSE!
I cannot judge what you should or should NOT do for maintenance. Every single situation is different.
My suggestion is every 30k, only for suspended particles in the fluid being removed.

For rear differential the 2005 manual states that there is no need to change this 75w/90 synthetic fluid unless there is a leak. :confused
I was also told by a GM rep that the rear end differential fluid that comes in Corvette is life long fluid?:confused
Who is correct here as i have never heard of this before.

Once again, depending on your driving conditions, it could be life long. But its the frictional modifier additive in the rear end lubricant that could break down and not do its job.

Also is Amsoil synthetic 75W/90 Severe Gear Fluid for rear end superior to whatever 75W/90 synthetic fluid GM uses?
What does GM use Mobil One for rear end too?

GM uses fluid based on their own lubrication standards, plus equivilants under API ratings, if applicable. The GM differential fluid specification, 9986115, MUST be on the bottle in order to use an aftermarket fluid. This information is in your owners manual.

Lots of questions but I appreciate your knowledge and information on this as I am getting different information on the preventative maintenance of these 2 components.

HI there,
My responses above are based on standard service practices in GM service information where applicable.
Your owners manual has the best part numbers for all lubricants.
Using GM specification fluid will ensure you car runs and lasts for the 300.000 miles that it was engineered to last for.
Allthebest, c4c5:bang

 

[abc]

HI there,
My responses above are based on standard service practices in GM service information where applicable.
Your owners manual has the best part numbers for all lubricants.
Using GM specification fluid will ensure you car runs and lasts for the 300.000 miles that it was engineered to last for.
Allthebest, c4c5:bang

Thanks again for providing all of that information. I have gotten so many different answers from a GM licensing rep telling me Redline doesn't have license for DEXRON III (H) to different dealerships that it has been :confused
One dealership told me since I don't track the car I won't notice any differences or get any benefits from using synthetic fluids over non-synthetic fluids on the 4 spd. automatic as far as shifting goes.
I do notice a major difference on my other car with a 5 spd. transmission using REDLINE MTL very smooth and slick shifting but again that car is a manual.
This car is a Corvette with a 4 spd. automatic transmission.
The dealership basically said save my $$$ and just stick with more frequent changes and that would be better than using the expensive synthetics like Amsoil, Redline or Royal Purple fluids.

what is your input on that as to which is a better product for rear end differentials, A-4 automatic transmission, engine oil for best protection?
1.Amsoil synthetic lubricants
2.Redline lubricants
3.Mobil One or whatever GM uses for its lubricants.
What would be the pecking order here?:cool

 

[c4c5specialist]

HI there,
I use ONLY GM lubricants and chemicals unless otherwise requested by the customers.
It is really very simple, IMO.
Engine oil must meet GM lubrication specification 4718M and it will be on the bottle.
Transmission fluid must meet Dexron 3 specification or BETTER, meaning 3H and Dexron 6 can also be used. As long as these classifications are on the bottle, you may use them, GM or anything else.
Axle lubricant must meet GM spec 9986115 and that must be on the bottle.
As for my personal order, Amsoil and Mobil One use the same synthetic stock for most of their lubricants.
The only reason I use Redline D4ATF is for the frictional package for c5 manual transmissions, otherwise, I do NOT.
Allthebest, c4c5

 

[ToolGuy]

I use Mobil1 engine and trans fluids... Nothing else.


:bang

 

[abc]

HI there,
I use ONLY GM lubricants and chemicals unless otherwise requested by the customers.
It is really very simple, IMO.
Engine oil must meet GM lubrication specification 4718M and it will be on the bottle.
Transmission fluid must meet Dexron 3 specification or BETTER, meaning 3H and Dexron 6 can also be used. As long as these classifications are on the bottle, you may use them, GM or anything else.
Axle lubricant must meet GM spec 9986115 and that must be on the bottle.
As for my personal order, Amsoil and Mobil One use the same synthetic stock for most of their lubricants.
The only reason I use Redline D4ATF is for the frictional package for c5 manual transmissions, otherwise, I do NOT.
Allthebest, c4c5

Again many thanks I have used Redline in my other car 88 Mustang GT 5.0 5 spd. with 3.55 rear end and have had great results with the MTL manual transmission as it now shifts slick and smooth. In the rear end differential I also have Redline in there but I can't feel any difference perhaps it gives more protection than the standard hypoid gear oil.
As far as the Corvette goes I'm game to try Amsoil as I hear it is the best but only on the rear end differential (2 quarts) as Amsoil doesn't meet the auto trans spec Dexron III (h) for the Corvette.
Redline D4 ATF meets the specs. but a GM rep. told me he didn't issue them a license (If that means anything but of course Redline claims they are compatible in both Rear end and auto transmission fluids on 2005 Corvette. Since I have only 11,200 miles on car and drive it easy but not as a daily driver everyday, I'll probably just wait on the differential unless it leaks or if there is chattering maybe change rear fluid in there at 25,000 miles and at the same time have the 4 spd. auto trans flushed, drained and changed with new filter.