Jim48

I had a recommendation from a friend that used to be a race car mechanic and now restores exotic cars (Ferrari's, Ford GT-40's, etc.) and he recommended Red Line MTL synthetic gear oil - used to have the same problem on the BMW's his team raced and that solved it. So I had it changed last Friday (first time, 75K miles). Took it out today and the first two shifts (fast ones) into fourth gear were noisy. After I had driven for about 20 minutes, the noise into fourth gear stopped, even for fast shifts. Shifting is a little stiff on startup (I had a B&M sport shifter installed but I don't mind the heavier feeling. It loosens up after a while. Strange thing: prior to having the B&M short shifter installed, I used to get the same noise shifting into fifth - original shifter was the standard one.

And for those respondents who saw the "Made in Japan" stamp on the standard transmission, Aisin was the supplier until Porsche went back to ZF, some time after the PDK was introduced in 2009. I think ZF now makes both the standard and the PDK for Porsche.

140.6er

Oh, I thought that they are now making 911s in Japan..

Jim48

Very droll

silver_tt

Be careful running Red Line. While not your gearbox specifically so YMMV, I had a 996TT Getrag gearbox that needed to be rebuilt ($$$) because the previous owner changed the fluid and used Red Line instead of the OE fluid (lied when I bought it from him and took it out of the "dealer only serviced" records, it passed an independent PPI, he was a famous athlete that is a dbag, etc). Very expensive mistake.........

Jim48

Thanks for the info - I'll watch things pretty closely as I don't want to turn it into a piece of junk, and I don't want to sell a piece of junk.

silver_tt

GBox (Stan) fixed my gearbox and he is the best in the country, if I were you I would call GBox and make sure. Costs you nothing but 5 minutes or less.................

https://www.gboxweb.com/

RennPart

We have a good supply of PTX in stock ready to ship. Porsche only sells it in a 20L jug so the only way to buy it is in bulk. We split it up into 1L containers for the everyday user who doesn't need a $650 jug of gearbox fluid.

https://rennpart.com/product/mobil-1...-90-1l-bottle/

KlausS98

The Redline seems to be GL-4 only, the mix of gearbox (GL-4) and differential (GL-5) requirements based on the combination of the two functions in one housing as used in our 911s needs exactly the GL-4/GL-5 specification mix as found in i.e. Mobilube PTX / Shell Spirax S5 ATE - a GL-4 only spec is certainly not recommended as it will not do much good to your differential. I would highly recommend to swap out that Redline ASAP.

Klaus

Bruce In Philly

2009 C2S 178K miles

Ok, I am about to offend some folks... oops... sorry.

Redline products are favored, according to my indy outside of Philly, by Ferrari guys. He said they love the stuff. So... you are thinking "if it is good for a Ferrari, then....". Um... wait a minute. Notice my indy said "Ferrari Guys". Now here is where I will offend some folks.... The majority... overwhelming majority... of "Ferrari Guys" I met over the years are just clueless. Clueless.

What to put into our manual transmissions? Hey, try something crazy! Koooky! Nuts even! How about reading your owner's manual? PTX is the stuff and it cured... well reduced... the 1st gear jam in my car. And yes, Klaus has it correct, PTX is a GL 4.5 formulation as is spec'd in our manual.

More reading here: https://rennlist.com/forums/997-foru...-gear-oil.html

Peace
Bruce in Philly (now Atlanta)

silver_tt

Ferraris are very different . Honestly a VW/Audi tech would be better on a Porsche than Ferrari. But there are specific things to these cars and you really want a Porsche specialist. I have been messing with these cars almost 20 years and I still learn new things about them sometimes.

I don't run a approved motor oil (Driven DI40). But I would never EVER think about running anything but OE fluid in the transmission/transaxle. Like I said, I learned the hard way and when it was all said and done it was a $5K+ mistake that I didn't even make but that was insanely cheap considering the only option Porsche will give you is to buy a new one $$$$. Stan is a busy guy but I spoke with him quite a bit and I can tell you if you knew what he knew you would not listen to the Ferrari guy. Anyway, I always just make it a point to let people know given how many people aren't aware of this and think other fluids are the same as the OE (There's the Mobilube PTX and I believe there is a Shell approved OE as well).