A week ago I picked up a 2006 6-speed Z51. Now I want to do a transmission and rear end fluid change, just so I know I'm up to date with everything. My question is what type of Royal Purple do I use? I did a bit of searching and I think I found out what I should use, I just want to make sure, because most of the information I found was on a z06.

In the transmission I use Royal Purple Syncromax 4 quarts.
In the rear end/Diff I use 75/90 gear oil 3 quarts.


Thanks Jerry...

 

I did my 05 Coupe. You are correct. For the rear diff I added about 4 oz of Transdapt friction modifier. The Royal Purple notes it contains the Modifier but I added it anyways. Autozone $5.00. I now notice less Gear noise at highway speeds in 6th.

 

Why change the fluid?

 

use what you want, but the OEM fluid for the rear diff is good stuff. Updated part # requires no friction modifier. Only pain is getting that little clip back on. buy an extra clip for $7 in case the old one breaks... better to have it and not need it.

 

good call on the clip, especially if you are a weekend kinda guy

 

If I remember correctly, its a generic clip that GM uses elsewhere for transmission lines, etc. Would be helpful to have the GM part number when you go to get it at your dealer. Unfortunately I don't have the part number.

 

Because (IMHO) fresh, clean fluid is preferable to older, dirty fluid.

I use Royal Purple as well. I change my transmission fluid about once a year (did it last week) and the differential fluid maybe ever two years. I track my car so I change fluids more often than most people...I believe its 'good practice.'

 

I follow the manufactures recommendations. More frequent fluid changes seem excessive, will not increase the car's value and you will replace the car for other reasons, example: I want launch control, or some other goody.

 

If the clip is the same as on the A6 lines the part number would be 24205103

 

Correct Tremec Transmission Lubricant: Manual Transmission Fluid GM P/N: 88861800

Correct AutomaticTransmission Lubricant: Dexron VI


Correct Differential Lubricant: DEXRON LS 75w-90 gear oil

 

Remember thats a DTE rear diff in that car. And they say to only use Redline 75w/140 synthetic gear lubricant. Might at least wanna give them a call and see what they say?

http://www.dynotech-eng.com/

 

I checked my 2005 manual and it states levels on transmission or rear end need no checking or drain and change unless there is a leak.
Sounds to me if it ain't broke don't fix it approach.
If that's the case then is the factory stuff better than Redline, Amsoil auto trans fluids and rear end differentials?

 

The manual says nothing about ever changing the diff fluid, just checking the level. If the rear end isn't making any noise, there is no reason to change it. It says to change the manual tranny fluid at 150,000 miles. So, why waste your time and money?

 

To answer the OP's original question-

Max Gear 75w90 is the Royal Purple product you are looking for.

 

Z51's have a diff cooler like that of the Z?

 

 

HI there,
GM engineered the Dexron 6 themselves and worked on the fluid for over 6 years before releasing it.

DEXRON-VI significantly improved fluid viscosity, shift performance and fluid durability during aggressive driving. GM tests have demonstrated that DEXRON-VI delivers more than twice the durability and stability in friction tests compared to existing fluids. DEXRON-VI has also shown superior performance in pitting, foaming, oxidation and shear stability tests.

You can view the information on the Dexron 6 in the bulletins section.

This forum will not be a basis to endorse other lubricants under any circumstances. We are not lubricant experts.

Dexron 3 licensing was revoked and the new Dexron VI was introduced.

Allthebest, c4c5

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I defer to the techs on the technical stuff but yes change it frequently under heavy/severe use is my thought. Dextron 6 is the way.. improvement in all areas especially trans wear and function with this newer rendition...subjecting the drivetrain to throttle causes heat in the components the A4 can only handle soo much temperature and the formulation increases/improves the operation within the the tranny. It is the way, as revealed by issues with other formulations/fluid.. the Techs are the indicator.. they see so many cars, cars with issues.. we might think/feel improvement in the short term the techs professionalism and exposure to a larger sample is the proof. Your question is significant and that is why this site is the best.. there are experts here.. check out C4C5's opinion on the fluid, he Knows the inside on Corvettes!

Hey welcome to the best site for techincal corvette information!
It has been discussed many times and it always comes back to dextron 6. Many issues have been eliminated by returning to the GM specified fluid. I dunno why but consistantly that is the recommendation. As for timing of fluid change, I dont think there is a reason other than financial to not excede the factory recommendation(change more frequently). I sure aint waiting 100k miles. Temperature is the enemy and clean fluid in the right amount especially for hard driven cars is your best defense. I change mine often cause fluid is cheaper than a rebuild/replacement. Best of Luck with your great car.

 

To add a twist to all this. Although Dexron VI is supposed to be backward compatible, there are a few cases where this is not true. For example, the tranny in the C6Z06 uses Dexron III. Now, based on what GM says, Dexron VI should work however GM has said to NOT use Dexron VI in the tranny but to stay with Dexron III.
Just a FYI.

 

I just read that they use the Dexron VI since it goes backwards to cover the Dexron 3(H). Remember though this is for an A-4.
I was considering Amsoil before I had an accident in another car but according to the other post you are just paying more $$$ for a name.
On the rear end diffs seems to be the majority here are having success with the Amsoil Severe gear.
AS far as the ATF on A-4? It's remains to be seen.

 

Gotcha. My experience when I had my 05 was the Amsoil worked just fine. Keep in mind that the Dexron VI is essentially a thinner fluid than the DexIII. Essentially they are doing what some manufacturers are doing with their oils, they are going with thinner fluids to eke out the most MPG they can get for their CAFE ratings. I went with the Amsoil.

The Amsoil Severe gear fluids have worked very well for just about all on the forum that have used them. They worked to fix the rear end "clunk" in both my 05 and my 08. So happy was I that I am using it in my Z06. There is a paper, I think you could find it on the Amsoil site, where they ran their gear oil against a number of other brands. Bottom line was, even though Amsoil was not best in every test, it was the best in most of the tests and pretty much best overall.

So the question on the tranny fluid boils down to, do you want a thinner fluid in there that should be okay or do you feel better staying with the spec. that originally came in there?