BuckeyeDrew

The consensus was to go with the factory fluids or DELVAC. Wanting to do this service this weekend I opted to go get it from Porsche. Had Delvac been available locally I would have opted for that as it is half the cost. Pelican only sells swepco and redline products (as far as I could tell). Suncoast sells Mobilube PTX and Shell Transaxle 75w-90. Both of these fluids show up when 996 gt3 is vehicle selected. The following quote is from the transaxle 75w-90 suncoast page:

"Factory approved transmission oil. SAE 75W-90, comes in 1 liter size. Fits most late model cars, always consult your owners manual to verify compatibility before using any fluid."

I did some online searches about PTX and Shell transaxle 75-90, and reading that either is ok. Hopefully that is correct.

Mikelly

I'll eat a little crow here... I just saw a chart in a manual that crossreferenced Shell Transaxle 75W90 with Mobi-PTX. Same numbers, same specs. "Good to know".

Mike

enthusiast

What chart and author? Porsche AG does make changes to recommended lubricants, just need proof.

Porsche AG has several 75 W 90 lubricants in their parts system. They don't contain the same chemicals, such as inhibitors for copper corrosion.

As of the 2010 PET the Mobilube PTX 75 W 90 is still the only lubricant specified for the 996-997 GT3 and several other models.

000 043 204 20 Mobilube PTX 75 W 90, in a 20 liter container

000 043 204 20L Mobilube PTX 75 W 90, now available in liter amounts from Suncoast Porsche according to their website. I cannot find this part number in the PET. I assume they are using new one gallon containers, made their own simple label, and can make customers happy selling them enough to do the lubricant change (taking the 3.3 liters or so out of the 20 liter container).

LVDell

I've been able to get the dealer to sell my "x" number of liters from the 20L drum if I bring a container. But this was some time back. I have completely moved over to Delvac for all my GT1 cars (6GT3, Turbo, 7GT3).

BuckeyeDrew

The dealer I got the shell transaxle from was Sunset Porsche in Beaverton Or. The parts "dude" said this was the reccomended fluid for 996 GT3 and the only fluid they sell. As I recall, it took him a few extra minutes to confirm this fluid as if he was double checking his info.

Vonschmidt

We stay with the oem for evething but the brake fluid. I also send my oil off to be analyzed at each change to monitor the levels and any buildup from wear. We use Blackstone on al the cars.

http://www.blackstone-labs.com/what-is-oil-analysis.php

BuckeyeDrew

Just wanted to update. I was able to get some of the services done yesterday:
air and cabin filter
plugs and coil packs
trans/diff fluid
(will do brake, coolant fluid, and fuel filter in the next few weeks as I ran out of time)

I was only able to drive the car normally last night due to rain, but so far the shifts feel the same with the new Shell fluid. I am not sure which fluid was previously used.

I also installed a splitter and cargraphic mufflers.

This was my first attempt at DIY maint.. And it really was not too difficult. Very glad i did it. I would say the most important detail was having access to a lift.

Mikelly

It was actually a fluids manual a guy at the local (to me) NAPA had is his large binder on the counter. I specifically asked for the specs on both for compatibility and he showed me both specs. This was NOT a Porsche document but a lubricant compatibility catalog. Never seen one before, but I'll try to get the name of it the next time I'm in there, probably later this week.

enthusiast

Hi,

I believe what you said but the parts guy is wrong. I have purchased Mobilube PTX 75 W 90 from Sunset Porsche and another Porsche dealership.

I think the dealers just hate to deal with that darn 20 liter container when they can cheat and sell you the other 75 W 90 stuff that comes in one liter/quart container. If they are doing the change in the service department it is easer for the tech to grab three one quart containers than measuring out 3 liters of the correct oil from the 20 liter container. This practice becomes a habit and then that is what the parts guy tells you, because their service department does it so often. It is also much easier to sell a retail customer the three quarts at around $100 than the correct lubricant in bulk at about $550. As 'LVDell' and I have said some dealerships will sell you x liters of the Mobilube PTX out of their 20 liter container.

Regardless, the dealerships didn't design the transaxle, so they need to follow the Porsche engineers' specs.

enthusiast

Thanks for answering my question. That is what I assumed.

Not acceptable unless it comes from Porsche AG.

LVDell

Bingo! I do this with all my p-cars. Every oil change and tranny fluid change. This is not only VERY important from a knowledge and health of the car aspect, but to make sure you are using the proper fluids and intervals. It also helps when you go to sell a car so you are able to document to the prospective buyer the state of the car and the maintenance history.

BuckeyeDrew

In the matter of acceptable trans/diff fluid, I presented Matt at GT Gears the following question:

I am a member on Rennlist and have read several threads about the GT3 LSD. Since you are regarded as the guru to rebuild these I figured you would be able to answer this simple question I have: Do I need to use the factory mobilube ptx 75-90 (which porsche tells me is now made by shell) for the trans and diff or is there a suitable alternative (such as liqui moly 75-90 synthetic or motul 75-90 synthetic or royal purple 75-90 synthetic).

And his response:

Any of the oils you mention will be fine. With a car that is tracked, changing the gear oil frequently tends to be more important than the particular oil. 4-6 track days max and then change it.


I was able to drive the car today as it was dry. And I did not notice any difference in the transmission/drivetrain with the Shell Transaxle gear oil.

Mikelly

This is ALL that matters to me:

[QUOTE=BuckeyeDrew;10188395]

And his response:

Any of the oils you mention will be fine. With a car that is tracked, changing the gear oil frequently tends to be more important than the particular oil. 4-6 track days max and then change it.

QUOTE]

'Nuff said.

GTgears

FYI,
I had a parts guy at a dealership that I trust implicitly recently tell me that Porsche is in the process of superceding the PTX into the Shell oil. While I doubt Mobil will stop making it anytime soon, don't be surprised if dealers who have traditionally stocked the PTX under a factory part number stock out and cannot get it for you anymore.

Regards,

Matt