Tiptronic Fluid Change Q

[tonycarreon]

so i know the AT fluid is supposed to be "lifetime" but the maintenance schedule recommends a change at 90k (i just hit 90k). my indy shop recommends against doing it since, as he says, "most problems happen after it's changed."

i'm wondering what other's have experienced after changing the fluid. i've noticed (last 5-10k miles) that shifting is getting (on occasion - maybe twice in the past 1k miles) harsher. it seems to slam into gear and there's a very noticeable jerk once it changes, almost always on downshifts.

[shlim8]

Hmmm.....

looks like I'm not alone.... my tip box was shifting perfectly and smoothly until I changed the fluid. Now it sometimes jerks violently into gear... usually from 2nd to 3rd or downshifting from 3rd to 2nd. No problems in other gears.

I'm on BMW (5-speed) ZF tip oil, what oil are you on ? I had thought of changing back to either Pentosin or original (also supposed to be Pentosin) to see if that's the problem. My friend's 996 also changed tip fluid about the same time, but he used the original oil and doesn't seem to have any problems.

What tip oil did you change to ?

[ketsa]

Did you also change a oil filter for tip box or just the fluid?

[tonycarreon]

Originally Posted by shlim8

:
I'm on BMW (5-speed) ZF tip oil, what oil are you on ? I had thought of changing back to either Pentosin or original (also supposed to be Pentosin) to see if that's the problem. My friend's 996 also changed tip fluid about the same time, but he used the original oil and doesn't seem to have any problems.

What tip oil did you change to ?

i have not yet changed ATF. still on the original fluid (90k miles, 10 years). from what i understand, it's imperative you use the correct fluid for the transmission and not try to "mix" other fluids or go with something "cheaper" to save a few bucks...

from the PP "101 projects" on the tip fluid change:

What type of fluid do you use in your automatic transmission? The Boxster requires a special type of fluid that you cannot easily find in most auto parts stores. The Porsche part number for the transmission fluid is 999-917-545-00, but is almost $35 a liter. The Boxster also can use off-the-shelf Esso LT 71141, or Pentosin ATF-1, both available along with gasket/filter kits from PelicanParts.com. I would avoid using any other type of fluid in your transmission. Also, use the same fluid for the entire replacement process - mixing and matching different types of transmission fluid can cause your transmission to fail.