sjfehr

$200 bet? Try a $2000 bet. Sorry, you may be 100% right, but I'm not gonna risk it over $20 worth of ATF.

Audi Junkie

3 flushes x 10q x $35 = $1,050 ...for fluid?

There is no "risk". I'm pretty sure MB uses ATF +4 in their trans.

Has anyone considered the possibility that there could be a BETTER fluid than OE Porsche, like MaxLife? How old is the Porsche spec anyway?

gfl

1. you do the service per ZF which is not a flush, it only takes about 5 qts

2. as noted the Audi fluid which is the same stuff, is about $10 or less, not $35.

So its 5 x say $9 = $45 for fluid. Every 30k+ . whoopie

Grant

Audi Junkie

So non-Porsche fluids are ok?

Just checking.

gfl

...any of the OEM fluids for the ZF boxes are essentially re-labeled Esso LT 71141. Could well be the Pentosin stuff that is in fact the same. If you have other fluids that claim to be chemically the same with the same additives, go for it.

But, if you actually read my posts, i said long ago that i would use one of the OEMs fluids or the esso fluid, but would hesitate to mix different fluids. I also said that experience shows that full flushes are dicey, so i assume we are mixing.

VW. Audi. Some BMWs. Some Jags. Porsche. Esso. Pentosin - but they must be LT 71141 - and I'd prefer to think they carried the exact same additive package.

Mobil1? Valvoline? Snake fancy? Might be great, but i would not mix them.

Grant

Audi Junkie

I'm pretty sure Valvoline covers this in one of their faqs. If I see it, Ill repost.

fwiw, many ATF products are licensed product, like +4. They REQUIRE a certain additive pack (from Lubrizol), mixed with a specified base oil. Therefore, ALL the brands carrying the label are exactly the same.

Your fears are unfounded. You don't trust M1, who OWNS Esso, with the correct 71141 spec? I can't help you then.

sjfehr

Porsche has a TSB out stating Pentosin ATF1 and Esso LT 71141 are the recommended replacement fluids, and approving them for mixing; both retail for around $17/L. The Porsche Part# on ZF's website crosses with LT 71141 on a number of vendor websites. The Boxster service manual leaked online provides the transmission flush procedure, (recommended by Porsche at 90k for my car) and only says to do it once, replacing 3.5L and the filter.

So, your "bet" is really whether to spend $68 on Porsche-recommended ATF, or take your word that other not-explicitly-approved alternatives are just as good for about $40 cheaper. The risk being destruction of a multi-thousand dollar transmission if it turns out you're wrong. Or even if I have no issues, it could potentially result in loss of a sale when I can't convince the next buyer that the cheap stuff is just as good as Porsche fluid, as Porsche buyers are often very fickle about these things. There are some things I'd take internet advice for or go aftermarket on, but for $40, it's simply not worth the risk to me.

You may know, though: Esso owns Pentosin, and I've heard Pentosin manufactuers LT 71141 for Esso. Is that true? Are LT 71141 and ATF1 actually identical formula fluids off the same production line but with different labels slapped on the bottle? The published fluid properties are slightly different for each, so it appears they might not be identical even if they're very similar. What are the differences?

Audi Junkie

ftr- this is just a theoretical discussion on the technical aspects of these fluids, not a cost-effectiveness analysis. Still, I believe otc products would win such a comparison. That being said, the "feel-good factor" doesn't really have a place in the discussion.

http://mbworld.org/forums/e-class-w2...r-atf-4-a.html

Anyway, this MBWorld thread covers a lot of ground on the subject. It involves more material than I wish to review at this time, but if there's a specific topic of interest, post it up and we'll go from there.


iirc, ATF-1 is more of a "Universal" product. I guess that means they use selective friction modifiers. Either way, these products are all the same hydrocrack base oil and a plop of additive. Keep away from Type F (non-detergent, for old farm equipment) and oddball Dex III, otherwise the modern ATF are all very good quality. Dex VI and ATF+4 are the newest and most stringent specs.

mgerber

Since you guys have a much deeper knowledge of ATF than I do, I figured I would ask this simple question: how often should the TIP fluid be changed to maximize the life of the trans? Mileage or time or both? Thanks!

Macster

When I asked some techs this question they told me if I wanted to change the fluid more often than the recommended change schedule to cut the miles by 2/3rds or half.

IOWs, say the change interval is 90K miles. Instead of changing the fluid at 90K miles change it at 60K miles or 45K miles to provide some (possibly) extra longevity.

AFAIK there is no call out to change the Tip (or manual) fluid on time. The change interval is based on miles only.

However, one can after a fashion derive some idea of how much time this represents.

Porsche figures these cars accumulate between 6K and 9K (on "average") per year. Thus for a 90K miles change interval this works out to every 10 to 15 years.

Cutting the above derived change interval to say 5 to 7 1/2 years seems reasonable.

Unless you are giving the tranny severe usage -- towing a trailer with your Boxster -- this is often enough. If I owned a Tip/PDK equipped car this is what I'd do (it is what I do with my manual equipped cars) and feel I've done my best to ensure the transmission gives as long as service as it possibly can.

The only thing I would do differently with a Tip/PDK equipped car is to throw in an early fluid change. At the end of break in (2K miles) while perhaps too soon is as good a time as any, provided always provided of course the owners manual doesn't prohibit early fluid changes. As is the case with the engine so it is the case with a new transmission and that is they are filthy, well, they make their oil/fluid filthy, shedding all sorts of trash (metal but also brake band/wet clutch friction material).

Now the Tip/PDK have pretty good filter systems so there's that but I would just feel better with an early fluid/filter change. Since I tend to keep my cars a long time and drive them a lot of miles I want to give not only the engines bu the transmissions an edge in the hopes it will result in increased longevity.

gfl

ZF, the manufacturer, states 50,000 miles for a "service". A service consists of dropping the pan, cleaning it, replacing the filterm and draining all the fluid that comes out readily - which is often less than 1/2 the total capacity.

I think that's reasonable.

My only ZF/tip is my Audi. I have done that for 90k so far, and on 4.2v*s they have been failing regularly. Mine is fine.

I use the Audi or pentosin fluid since those are exactly the same as the 60% of the fluid that remains. Audi Junkie thinks this is a waste of time, and that may well be so.

in any event make sure the fluid is labelled with the Esso spec LT-somethingorother.

Grant

sjfehr

Well, I did the ATF flush today; went fairly smoothly. Nothing difficult, just time consuming- I changed my oil at the same time and was on the lift a little over 5 hours. The worst issue was having to clean out all the gunk in all the torx heads.

Couple surprises- first was that when I opened the fill port to check how low the level was, I ended up unexpectedly drenching my arm in warm ATF. I thought for sure I was low! I put in about 3 1/4 qts. And then, later, after warming the fluid and expecting from all the operating temperature warnings that all the "cold" ATF would have expanded, pulled the fill cap again, and... nothing. I suspect my car was not level on the 2-post lift (probably should have pulled in backwards to get the CG closer to the posts) and am going to lay out some 2x10s to level it up in my garage this weekend and top it off again to be sure.

Macster

The transmission fluid temperature must be between 30C and 45C. Too cold and you will overfill the transmission with fluid and too warm and you will under fill the transmission with fluid.

mgerber

Thanks guys. Our Boxster has 10K miles and is an '07. It pretty much comes out on sunny days for PCA drives. I was debating on changing the Tip fluid during the "put it away for the winter" oil change last November, but was talked out of it. Like Macster we (aka my wife) wants to keep this one forever as she loves it, so I did not feel good about being talked out of this service. I will get it done in the Spring when the car comes out of hibernation.

Audi Junkie

A 2002 at 45k, I'll do it this summer. Does anyone have the filter change procedure? I'll look for an easy place to do a complete flush when I get in there. MaxLife it will be.

The ATF is an important choice, unlike mundane fluid choices such as coolant or washer fluid.