Transmission Grinding when cold?

[Brian997]

The car doesn't seem to ever do this for the dealer, but does it fairly reliably for me when the car is below freezing and the oil hasn't warmed up yet. Shifting from 3rd to 4th and 4th to 5th makes a horrible grinding sound like it was a missed shift or I didn't have the clutch in. I'm exceptionally careful and the clutch is definitely in. I can avoid it by pausing in between gears but it happens when completing the shift in a single motion. Only 3-4 and 4-5. Once the oil temperature comes up, there's nothing I can do to make the noise happen. Tranny works beautifully otherwise.

I'm inclined to say the syncro's are fubar'd but wouldn't they display the odd issue once the car was warm? It also doesn't happen in the summer months at all.

The car is a 2006 C2S. Thoughts?

[JFP in PA]

When was the last time the gear box was serviced? And what gear oil is in it?

We see this type of complaint when the gear oil is really beat, or someone has put the wrong type in the trans...........

[RFM]

+1 for the gear oil, service?, type? and level?. Hope there is no short shifter installed, this makes it even worse under cold conditions.

[Jobu]

I'm interested in this topic as I also have an '06C2S. Mine has 38k and I'm thinking about changing the gearbox oil. Any recommendations on brand and type? Have I waited too long?

[Loren]

Use only factory approved transmission oils as specified in the TSB.

[JFP in PA]

I'm interested in this topic as I also have an '06C2S. Mine has 38k and I'm thinking about changing the gearbox oil. Any recommendations on brand and type? Have I waited too long?

+1 on Loren's comments. We have looked at just about everything available, and consistently come back to the factory fill. Porsche uses very unusual specs for their choices, making them rather unique. While smaller "blenders" like Redline, Royal Purple and Amsoil typically all claim to have matching products, experience (and testing) has shown they do not. Several of the major oil companies have actually responded to question about their products by stating that, because of Porsche's unique specs, they have nothing suitable. A couple have gone as far as to state "use what the factory recommends".

Considering what these gearboxes cost, that is not bad advice……………

[Brian997]

I asked about replacing the gear oil and got a strange look and dismissal from the dealer. The car just clicked over 40,000kms (25k miles). I've owned the car since it was 1 year old, so I assume it has never been done. I haven't had it done. It does have the factory installed short shift.

Does anyone know if it is the same syncro that does 4 and 5? I'm curious why it is only those two gears.

[JFP in PA]

3 & 4 are one syncro, 5 & 6 are another. Rather unusual for two different syncros to go bad at once. I'd still bet on the gear oil..............

[Steve Kellett]

I read up a lot on this issue and concluded the lube the dealer uses is the correct one. At the 12 year mark I had the dealer change the fluid and while it was in bleed the clutch. The trans shifts super smooth once warmed up but is a bit hesitant when its cold to go into 2nd so I go 1st to 3rd until shes warm then no issues.