Redd

I have previously used Mobil's premium synthetic lubricants in transmissions and differentials, and as I recall even for those, the service life of the fluid is suggested as 40,000 miles.

I think we all know that most differentials and transmissions (of whatever type) run for 100,000 or 150,000 miles without any fluid change, and that's certainly "lifetime" for most cars.

But ZF are not alone in saying that these components WILL work better and longer when the "oil" in them is changed on schedule.

How very odd that Audi is perhaps the only maker that insist on changing the brake fluid every second year (most say their brake fluid is a "forever" fill) while they ignore the expensive damage that can be caught or prevented with gearbox fluid changes.

HerrK

Most OEM have switched to DOT5 brake fluid which is hydrophobic (repell water) as opposed to DOT4 & 3 which are hydroscopic (absorb water). Water in the DOT 4 & lower versions lowers the boiling point of the fluid, which creates gas in the fluid (during repeated braking ) and thus the mushy pedal feel - if the fluid is not changed on a regular basis.

BMW still utilizes DOT 4 and recommends 2 yr change out (as is should be). DOT 4 & 5 are not compatible so you can't simply put DOT 5 in a DOT 4 system due to seal material incompatibilities.

Redd

"Most OEM have switched to DOT5 brake fluid"
That's news to me. I ran it for 25+ years and right through last year, it was always the oddball fluid on the US market.

Perhaps you are confusing DOT5.1 with DOT5. The former is a high grade conventional fluid, the latter is a silicone based fluid that is incompatible with everything else on the market.

"5.1" should never have been named that way, it creates gross confusion since it "should" be a variation on DOT5, which it isn't.

spijun

If you're interested, this is the oil for 8-Speed ​​Automatic Transmission S/N: Audi G060162A2 or ZF LifeGuard8 ZF S/N: AA00 601 304

http://www.ecstuning.com/Search/G060162a2/ES2226196/
or
http://www.ecstuning.com/Search/G060162a2/ES465422/

brutus23079

Thanks for the info Spijun. Sheesh, talk about sticker shock! And I thought $21/qt for Nissan CVT fluid (for a long-since-traded-off '03 Murano) was ridiculous. Just did a 2x drain/fill on my wife's Ford Edge. Cost for Mercon V ATF: About $6/qt with tax. At least we have plenty of time to try and find Lifeguard8 on sale somewhere (yeah, like that's ever gonna happen). If anyone does somehow find it on a big sale, please let the forum know. I'll keep an eye out as well...

Redd

I don't think ZF is a petrochemical company, so that means they contract out for their fluids. Unless they are contracting for extra-special Magic FooFoo Dust in their lubes, the same product should be available from Mobil, Shell, or other sources. One of whom must be supplying the ZF mix.

Or, once every 50,000 miles, you, ah, bend over and use the official lubricant.

MP4.2+6.0

You cannot mix DOT 5 (silicone based) with either 4 or 3, and DOT 5 is hardly used. To switch to it, you need to completely flush the brake system of all traces of prior "normal" fluid. DOT 5.1 is perhaps what the poster is talking about, but it remains hydroscopic and subject to periodic change intervals. http://en.wikipedia.org/wiki/DOT_5.1

Instead, what should be of interest to Q5 owners are the changes to the prior DOT 4 basic spec fluids. The purpose is to reduce viscocities at very low temps to improve ESP reaction times. This is also better known at SL6 in Ate speak or DOT 4 LV (low viscosity) by various other suppliers.

In Audi's world, it is VW standard 501 14, which it continues to call DOT 4. Here is a VW blurb on it: http://www.vw.com/en/owners/parts-an...ake-fluid.html Now sold by Audi dealers as the standard fill. Ate Typ 200 in DOT 4 Amber continues to have marginally higher wet and dry boiling specs, but VW's are already high by normal DOT 4 specs, and it has the low viscosity extreme cold supposed advantage.

MP4.2+6.0

except perhaps to jobbers in barrel quantities. Sometimes also a Shell # for prior gen guilds.

The basic current choices are the Audi numbered fluid, or the same ZF LifeGuard 8 green colored stuff. ZF pricing on line and AudiUSA Parts discounted dealer pricing are similar. I know about this because Audi and ZF transitioned the spec to ZF 8 for various of the lat generation (D3) A8's six speeds.

Since the 8 speed ZF tranny is being so widely used in BMWs and Jags (like always for prior generations), but now also in some domestic and Asian vehicles, I would expect more fluids to come out over time that list specific compatibility.

Since the Q5 Hybrid actually calls for a tranny fluid change at every major service interval (unlike any other Q5 or conventional AT Audi), I will be watching the dealer do this under AudiCare, and then Extended AudiCare. I figure on buying extended AudiCare in due course given the tranny fluid change anomaly for Hybrids that makes AudiCare more compelling at the same price.

brutus23079

Good point MP4.2+6.0 regarding worldwide use of ZF transmissions. With such a large market for ZF-equivalent tranny fluid, manufacturers are obviously going to work hard trying to make a product to meet that demand. Poking around the internet, here's one such shot out of the gate:

http://www.motul.com/gb/en/news/Prod...zf-lifeguard-8

No other info other than the link, but it's a start to creating competition...

spijun

ZF-8speed technical information in German and English (PowerPoint)
www.sussexautos.co.uk/images/zf/zf-8speed.ppt


ZF-Lifeguardfluid 8 is available in packaging of 1 liter can, 200 liter barrel and 1000 liter IBC. The approved oil can be found in the ZF list of lubricants TE-ML-11 .

List of lubricants TE-ML 11:
https://www03apps.zf.com/interoelepd...011_en0700.pdf