997-1 Transmission Fluid Change

[stevencr]

I'm preparing to tackle the transmission fluid change on my manual 2006 997S. I've purchased one gallon of Mobil 75-90 Delvac Synthetic gear oil for the job. Does anyone know the exact capacity of the gear box? I'm pretty sure 1 gallon will suffice but read recently on another forum that just over 1 gallon is necessary for filling to the upper fill plug.

Thanks for the help.

[Loren]

I'm preparing to tackle the transmission fluid change on my manual 2006 997S. I've purchased one gallon of Mobil 75-90 Delvac Synthetic gear oil for the job. Does anyone know the exact capacity of the gear box? I'm pretty sure 1 gallon will suffice but read recently on another forum that just over 1 gallon is necessary for filling to the upper fill plug.

Thanks for the help.

It's in your Owners manual (page 291). If you don't have one you can download it here

"approx. 3.1 quarts / 2.9 liters transmission oil"

[stevencr]

Duh! Sorry about that. Thanks so much Loren.

[Jobu]

I'm preparing to tackle the transmission fluid change on my manual 2006 997S. I've purchased one gallon of Mobil 75-90 Delvac Synthetic gear oil for the job. Does anyone know the exact capacity of the gear box? I'm pretty sure 1 gallon will suffice but read recently on another forum that just over 1 gallon is necessary for filling to the upper fill plug.

Thanks for the help.

How did you choose Delvac? Did you consult the approved list, and if so can you post it!?! :) I'm thinking of doing the same for my '06 C2S also!

[stevencr]

I chose Delvac after doing a fair amount of research. I was under the impression this was OEM fluid. Could be wrong though.

[PAULSPEED]

I would have the dealer change the fluid.

Paul

[cbzzoom]

I would have the dealer change the fluid.

Paul

Because you enjoy paying huge amounts for very trivial services? Changing the trans fluid is *really* easy and almost impossible to do wrong, because you just fill it as far as it will go. (obviously under warranty don't DIY)

About the Delvac : my understanding is that the OEM fluid was Mobilube PTX or Shell Transaxle , but consumers can't buy that. I've seen around the net that some people seem to be using Delvac successfully but it's definitely not the same. I imagine the best place to get OEM fluid is from Sunset or such like.

Pelican shows Swepco 201 and Red Line 75-90 for our cars. It would be interesting to start getting reports from people trying different fluids, as I find the OEM fluid is too thick in cold weather - the first few shifts before warming the car are very stiff.

Edited December 22, 2010 by cbzzoom

[Loren]

I would stick with the factory (approved and recommended) transmission oils. There have been reports of problems with some 3rd party oils - that oddly enough went away when they switched back to factory fill.

[JFP in PA]

+1 on Loren's comments; we have encountered exactly the same thing. Clients that have tried everything imaginable, from Red Line, Royal Purple, Amsoil, to Mobil 1 products have all ended up both disappointed with the shifting and noisy gearbox complaints, and ended up switching back to the OEM juice. We did see one product that seemed to work well, particularly in the cold, but it is not sold in North America, so while an interesting footnote, it is not a viable solution...............

[PAULSPEED]

I went to a good independent shop to have the

fluid replaced. They told me that they would have

to buy a 50 gallon drum because that is the smallest

container the fluid is shipped in.

I would not want to put Audi fluid in a Porsche. Maybe

Mercedes fluid, but I bet that their fluid also comes

in 50 Gallon containers.

Paul

[JFP in PA]

Porsche does retail their gear oils in liter containers, but not all dealers seem to carry it. For someone doing a DIY change out, that would be the way to go. Shops usually buy theirs in either drums (due to cost) or 5 gallon pails, the latter of which I understand have been discontinued due to lack of sales.

[cbzzoom]

BTW this just came up at the same time on Rennlist :

http://forums.rennlist.com/rennforums/997-forum/401471-6-speed-manual-trans-oil-change.html

I did some research and it appears that the Porsche OEM fill that they call "Shell Transaxle" is in fact Shell Helix Racing 75W90.

If you look at a viscosity chart :

http://www.bobistheoilguy.com/visc.html

it's obvious that 75W90 is a very loose spec, so they are absolutely not interchangeable. In particular, the Shell Helix Racing is one of the thinnest 75W90's you can get - most of them (Red Line, etc) are thicker, particularly at low temp.

The OEM fills (PTX and Shell) have very high Viscosity Index, close to 200, while many of the other oils are around 160-180. Higher viscosity index means the viscosity is closer to constant over the range of temperatures.

[Loren]

BTW this just came up at the same time on Rennlist :

http://forums.rennli...oil-change.html

I did some research and it appears that the Porsche OEM fill that they call "Shell Transaxle" is in fact Shell Helix Racing 75W90.

If you look at a viscosity chart :

http://www.bobistheo...y.com/visc.html

it's obvious that 75W90 is a very loose spec, so they are absolutely not interchangeable. In particular, the Shell Helix Racing is one of the thinnest 75W90's you can get - most of them (Red Line, etc) are thicker, particularly at low temp.

The OEM fills (PTX and Shell) have very high Viscosity Index, close to 200, while many of the other oils are around 160-180. Higher viscosity index means the viscosity is closer to constant over the range of temperatures.

Are you sure that it is Shell Transaxle in the 997? The parts list shows a different Porsche number.

I have not seen a TSB on this but the Shell Transaxle was used on the 996 series (which is a different transmission made by a different company).

[leocanto]

So, which oil did you use? And is the a DIY tutorial for this? My shifting is not the greatest sometimes and I would like to see if this will help.

[Loren]

So, which oil did you use? And is the a DIY tutorial for this? My shifting is not the greatest sometimes and I would like to see if this will help.

DIY is the same as on the 996 series.

[leocanto]

Thank you Loren!!!

One final question, on the DIY, after drain the oil, it just say to refill with new oil....but where? I'm not sure on the 997 is the reservoir for the transmission oil. Is there a hose that goes up to the engine?

[Loren]

Thank you Loren!!!

One final question, on the DIY, after drain the oil, it just say to refill with new oil....but where? I'm not sure on the 997 is the reservoir for the transmission oil. Is there a hose that goes up to the engine?

No hose to the engine look at item 1 in the DIY diagram - that is fill plug.

[Dus10R]

This is an old topic but I figured I would throw in my experience.

I switched to Delvac at the recommendation of my indy shop.

BAD MOVE. Now if you live in a warm climate year round you may never notice a problem, but I live in Reno and it gets cold during the winter. After starting the car I could only get the car into First gear if I came to a complete stop and Second gear required double clutching, third through 6 was okay and once the gear box was up to temp it was better but still very hard to get into first unless stopped. Now that the temps are warmer its nowhere near as bad but still not perfect. After doing some research it appears these Japanese transmissions are really particular about the fluid, and the only one that is known to function well is the OEM fluid. So I'm switching back here shortly. Just my .02

[mghorayeb]

I had my fluid changed at the dealer at around 55k kms several months ago. The weather is crazy hot here, and the car is tracked a couple times a year. Either way, I like to get on it regularly...I had been experiencing some grinding (more tactile than aural), especially when "cold", and mostly going from 5th to 6th (but generally around 4th, 5th, and 6th). I believe the Porsche recommended fluid replacement interval was around 120k kms. Everyone here (including those at Porsche) told me that changing the fluid would exacerbate the problem, but my other options were ugly (costly transmission repair or replacement), so I insisted on the cheap/easy option. It took a couple days for the transmission to smooth out to normal - I imagine the new oil had to get into all the nooks and crannies. I definitely recommend changing the transmission fluid much earlier than recommended, and after considerable research (on this site and others), opted for OEM fluid change at the dealer. If I remember, it only cost me about $175, and was well worth it. In general, Porsche knows best.