Hello everyone, this is my first post in the forum.
I recently bought a
Porsche Boxster
S
987.1
3.2L Tiptronic 2006, with ~23,000Km on the clock.
Having a low mileage but being a 19 year-old car, I thought it could benefit from a transmission fluid change.
I have heard that, if high-mileage cars didn't have a transmission fluid change, perhaps it would be better to leave them untouched since a transmission fluid change could do more harm that good.
However, if the mileage is low it could be beneficial to do a transmission fluid change because its properties deteriorate over time.
From what I understand, Tiptronic gear boxes on cars like mine can hold up to 9L of transmission fluid. However, when draining it you only get about 3.5L because the rest is stored inside the torque converter, which cannot be drained without disassembling.
So,what you can do is replace 3.5L, drive the car so all the transmission fluid (including the one inside the torque converter) is mixed together, and repeat the process again. After a few iterations, almost all the transmission fluid will be replaced. I have cooked a small program that calculates how much % of transmission fluid is replaced depending on the total capacity, the quantity of liters replaced on each iteration, and the number of iterations:
Code:
$ ./foo.py --capacity=9 --replace=3.5
Replacements
Old oil replaced
New oil used
0
0%
0L
1
38.89%
3.5L
2
62.65%
7.0L
3
77.18%
10.5L
4
86.05%
14.0L
5
91.48%
17.5L
6
94.79%
21.0L
7
96.82%
24.5L
8
98.05%
28.0L
9
98.81%
31.5L
10
99.27%
35.0L
11
99.56%
38.5L
12
99.73%
42.0L
13
99.83%
45.5L
14
99.90%
49.0L
15
99.94%
52.5L
16
99.96%
56.0L
17
99.98%
59.5L
18
99.99%
63.0L
19
99.99%
66.5L
20
99.99%
70.0L
21
100.00%
73.5L
100% means anything higher or equal than 99.995%, since it's round up to two decimal digits.
What we can observe is that there isn't much gain on repeating the process more than 8 times, and perhaps taking into account the money cost of the transmission fluid, repeating it 3, 4 or 5 times would be the most sensible choices.
Now what I need to know is how to replace the transmission fluid correctly.
I came across this (/posts/239839/) and this other (/posts/239988/) posts (sorry, I'm not allow to put links on my first message) on this page, and in there is says:
So, based on that, after you open the filler plug, automatically ~2 liters drain out from it.
Later, it says:
There is something that I'm missing here.
Regarding "I would then go to the back of the car and pump in fluid until it starts flowing back out the filler plug"..., if the fluid automatically drains out from the filler plug when you open it, how can you refill those ~2 liters back in there? Wouldn't the fluid come out automatically right after you pump it inside? How can it stay in there, and before (when you opened the plug) it couldn't?
Regarding "quickly insert[ing] the plug"..., wouldn't the fluid drain out again while you try to insert the plug?
Regarding "I would first replace the extra fluid which I sucked out (~2 liters) then start the engine."..., at that time there are other ~2 liters missing (the ones that drain out after opening the filler plug). Is it safe to start the engine (and run through the gears) with that lack of fluid?
Regarding "After running through the gears and then back into park"..., does that mean going from P, to R, to N, to D, and finally back to P? Or does it mean also going to M, and then run through 1, 2, 3, 4 and 5?
I hope you can resolve my doubts.
Thank you in advance.
Allow me to ask another related question about which transmission fluid is suitable for my car (
Boxster S
Tiptronic
987.1
3.2L 2006).
I have seen in the
FCP Euro
Web site some fitting fluids for my car:
ZF Lifeguard 5 (it says that is equivalent to Esso LT 71141)
Fuchs Titan ATF 6006
Pentosin ATF 6 (it says that meets Shell 1375.4 specifications)
Liqui Moly Top Tec ATF 1200 (it says that meets Dexron III H specifications)
Where I live, I cannot buy any of those fluids at a reasonable price, therefore I was looking for an alternative.
I had a look at the data sheet of those four fluids, and I could find something that is very similar (more or less between the ZF Lifeguard 5 and the Fuchs Titan ATF 6006). The name of that fluid is Cumic ATF DIII-H (made in Japan, and meets Dexron III H specifications). Here is a table comparing the data sheets of all products:
ZF Lifeguard 5
Fuchs Titan ATF 6006
Pentosin ATF 6
Liqui Moly Top Tec ATF 1200
Cumic ATF DIII-H
Density at 15 °C (g/ml)
0.85
0.844
0.844
0.85
0.843
Viscosity at 40°C (mm2/s)
37.0
28.3
28.5
36.4
34.17
Viscosity at 100°C (mm2/s)
7.6
6.0
6.0
6.9
7.206
Brookfield/Dynamic viscosity at -40°C (mPa.s)
16,000
8,750
-
<= 20,000
-
Pour point (°C)
-51
-42
-39
-54
-47.5
Flash point (COC) (°C)
220
202
-
230
230
pH Value
-
-
Slightly Alkaline
-
Slightly Alkaline
Viscosity index
-
163
164
150
182
What do you think? Will it be safe to use that "Cumic ATF DIII-H" in my car?
I've gotta comment on what great posts your first posts here are - and excellent questions.
The issue of the excess fluid (which would seem to be above the filler level) is mostly caused by oil being in the clutches and hydraulic circuits of the tranny.
A rule of thumb my mechanic uses (and he's changed 100's of cars transmission fluids..) "put back in what you take out." Measure what you get out of the transmission then put that amount back in. Unless the transmission was leaking, or there were indications of low fluid (slipping clutches, delayed shifts) - this will get you back into safe fluid level territory.
I'm sorry I have no suggestion, but Fuchs fluids I've used have been good. What does their website say to use?
Hello
@deilenberger
, first of all, thank you for taking your time to answer some of my questions.
So..., when you open the filler plug, there is fluid above the filler level, right? That's why it drains out as soon as you open the filler plug.
So..., you will drain out that fluid above the filler level, plus, all the fluid that drains out from the drain plug.
So..., if you try to put back the same quantity of fluid, it will be again above the filler level, right?
How is it possible then to put back the same quantity? Wouldn't it drain out as soon as you exceed the filler level?
Uhm..., I'm sorry, I don't understand your question. The website of whom?
The " don't change old fluid" is a old wives tale".
New fluid is always better than old/dirty/burnt fluid.
If what comes out looks clean and does not smell burnt, just do a simple refill.
If it does not look good drop the pan, change the filter and magnets.
If you are the worrying kind about a week later do another change.
If it looks really bad (I would doubt the case) do a total of 4 changes.
Drive and enjoy.
Just looked at my copy of the
987.1
factory service manual. There is a very unusual method for changing the Tiptronic fluid.
First of all, there is a special tool called the "filling device" (VAG 1924 00000) that is used. The filler
plug
is at the bottom of the pan and this device squirts (or something) the fluid up into the pan. Check this out:
Also the trans oil temp must be in a specific range with the motor running at idle. The manual states clearly that the amount of fluid for a replacement is 3.5L. You only put 9L into a dry transmission (i.e. after a rebuild or other teardown).
I would encourage you to look this up as it is definitely not just a matter of "filling to the bottom of the fill hole."
The same sort of device was used on the 6 speed automatic on the 955 series Cayenne.. I actually bought one once, I have no idea where it ever got to, or if it could be used on these transmissions, but it basically squirted the fluid into the transmission from the bottom up through a pipe that remained in the transmission after filling it. The drain plug was a two part thing with the entire plugs and pipe being removed to drain the trans, then replaced and a smaller plug that screwed into the pipe was removed, and a pressure fitting screwed in it's place and the fluid was pumped into the system until it was "full" - the transmission was then ran ujntil temperature was reached and that fill plug would be removed, any fluid above the level of the pipe up into the sump would drain out of the pipe, setting the fluid level.
Can we engineer anything more complex? Jah! I'm sure we can..
Very common on European transmissions.
The short tube sets the level when the engine is running and at normal temps.
When you stop the engine more fuid return to the pan.
I'm still undecided about this... According to my research, the transmission installed in my
Porsche Boxster
S Tiptronic
987.1
3.2L 2006, is a "ZF 5HP19/01" (5-speed automatic).
The manufacturer is ZF, and the recommended fluid is ZF Lifeguard Fluid 5.
My research about if it's feasible to replace that fluid with a different one (I had in mind that Cumic ATF DIII-H fluid) just left me with even more doubts.
Apparently, just trying to match the numbers of the data sheet is not enough, and there might be other things to consider, such as:
Compatibility with the transmission's sealing materials.
Friction modifiers.
Additives.
Dexron III-H fluids are formulated for GM transmissions, and while they may meet certain basic specifications, they are not specifically formulated for ZF transmissions.
AND the engine running IS critical since the level will rise when you shut off the engine and the oil drains out of the control circuits. You can't do it with the engine off.
Since a replacement transmission is likely a good portion of the value of an '06 987.. you might just consider buying the
PORSCHE
fluid for it. You aren't going to use that much, most of the fluid stays in the transmission when you open the drain plugs - it's in the control circuits and clutches. The difference in cost is maybe $100 - vs $10,000 for a new transmission. Easy odds on that one. Use the real stuff. And put back the same amount as came out.
