Sarg

iTrader: (6)

So in looking at service recommendations for my wife's new V, it shows that fluid does not need to be changed? I was planning on giving the car a once through and tuning it. What do you guys recommend on this? Best to leave it as it is or go ahead and get some fresh synthetic fluid in the diff and trans? Car has 125k miles on it. It just seems that all fluid must have to wear out eventually....

BudRacing

iTrader: (3)

Absolutely. I recommend Amsoil for both.

Sarg

iTrader: (6)

Had a friend who told me that was what he used in his GTO. I am guessing the two are very similar. If you do change it, how often should it be changed?

Zexell

iTrader: (1)

Typically most Amsoil users do not go off of your standard service intervals. IE: 3 months oil change may go 6-8 months for Amsoil users.

Personally, I run Mobil 1 and leave it be. Amsoil is a FANTASTIC product and company, just hard to come by locally for me.

Sarg

iTrader: (6)

For the Diff and transmission? That is the thing, there is no recommended service interval on these that I could find.

BudRacing

iTrader: (3)

Use severe gear in the diff and torque drive in the trans.

Stepside

What year is your CTS-V ? 1st Gen? or 2nd Gen?

When I owned an '07 V I used the Castrol ATF (not synthetic) in the Trans, that is compatible with Dexron III spec.

I used Valvoline (Limited Slip) synthetic 70/90 in the Differential.

You'll have to pump it IN.
Be sure to remove the Fill Plug 1st . . before the Drain Plug.

gangnam style

i'd change it (all fluids) annually at the very least but that's me.

the only one that doesn't is the coolant but that's 2yr interval unless temps inexplicably spike (haven't yet)

Sarg

iTrader: (6)

It is a 2005 1st gen cts-v. Just seems like changing the fluids would be recommended in the service manual. I have never heard of just leaving fluid in and calling it good, lol.

Dmax/04V

Trans and diff fluids can usually do 50K easy on a given batch of fluid, but it comes down to how you drive it. Barring problems, and excessive mileage I would change the diff and trans fluids every 50K. When it comes to those of us who track these cars whether it be auto x, or drags the intervals change to whatever is needed or preference demands. Another vote for amsoil here as well.

Stepside

On another note and slightly But, talkin' fluid change . .
Be concerned about your clutch fluid.

Read this: http://www.rangeracceleration.com/Clutch_Care.html

Then,
go buy the necessary products and get "crackly-akin"

Sarg

iTrader: (6)

Good to know!