Dougdoescars

I recently purchased a 2005 997.1 C2S and it has been a joy to drive. My only issue that I noticed is upon driving when the car was dead cold, gears 4-6 would be a bit crunchy going in. Like the slightest grind. It didn't feel resistant or hard to go into gear, its just a bit of a crunch and its definitely not pleasant. To combat this, when I shift into the gears a little slower (like a .5 second pause at neutral before going into the next gear), it would go in without any crunchy/grindy noises. After about 5 miles of driving or so when the trans is fully warmed up, every gear goes in with no issue.

I did flush the transmission and use Mobilube PTX 75w-90, but the issue still persists. I was worried it might be a worn synchros, but some people have told me that if the synchros was bad, it would be grinding every time it went into gear.

Anyone have any insight on what the culprit might be, and whats the best way to fix it? Its not like its the end of the world, shifting a hair bit slower while the car warms up is no issue but I figured if I could fix it or at least figure out what the problem is that'd be a nice peace of mind.

carguy999

Similar sounding to what I was experiencing but my local indy had used some Rennline trans fluid; after I changed to Mobilube the issues completely went away. I'm no expert but there's probably not a great way to tell without cracking open the case - when you changed fluid did you notice any metal in the oil as it drained?

Dougdoescars

No metal was found luckily. I swapped to mobilube as well but unfortunately the issue still persists.

r_towle

How many miles?
might be time for a clutch.
could be the pressure plate is no longer strong enough to fully release, or the flywheel is warped, or the disk is not moving in and out freely anymore

Dougdoescars

Just cracked 100k miles, based on the carfax report I received for the car the clutch was replaced @ 91k miles along with the pressure plate and slave cylinder.

Bruce In Philly

2009 C2S 191K miles

As far as I know, changing the fluid to PTX is pretty much all you can do. Sounds like you have synchro wear... the points are wearing round. Change the fluid every 30K miles or so, just my opinion, and treat it carefully. I found pressing the clutch in fully, all the way down, can help but... who knows, this is a wonky transmission IMO.

Peace
Bruce in Philly (now Atlanta)

Dougdoescars

Unfortunately this is what I'm starting to suspect too. I've switched out the shifter and shifter cables as well so theres no way those can be the culprit.

Looks like I'll just have to be a little careful during the first 4-5 miles of my commute with the car!

Wayne Smith

I've rebuilt a transmission or two, or three ...

Threads like this make me happy I've got a PDK (yeah, flame on)!!!!!

It's a standard to let motor oil warm up before running hard. Transmissions can be the same way. Two of my three cars have a transmission oil temperature gauge. There's a reason for that.

carguy999

For those of you responding here - how safe is it to just baby the car for the first few miles? Like I said in my case, it is still a little tough to get into gear / occasionally grindy shifting into second when cold. My local shop recommended pulling the gearbox apart to fix it, but if I can avoid spending like 10k or whatever by just being a little gentler before the car warms up, that is A-OK with me. Is that a viable option?

rileyracing1

When these transmissions are cold they tend to exhibit as described . I find myself sometimes at a light where the car does not want to go into 1st and I simply put it into 2nd for a second until the tires move slightly and then 1st goes in no problem. My sport bikes do the exact same thing when cold. Some transmission designs / gear ratios are just this way and even more so when cold , I have been dealing with this on one toy or another for 40+ years ...it's nothing to worry about as long as you don't get grinding.

r_towle

Started with 914 transmissions in my Porsche experience, then to 911/915 transmission.

the 997 feels amazing to me

my HS vehicles were aircooled busses.

groovzilla

Another of the many PDK owners finding out his transmission is toast

Wayne Smith

To make transmissions smaller and lighter gears get cut squarer. Treat it gently while the gear oil reaches temperature. You'll be fine. If it gets worse with uncontrollable grinding the bill will be the same then as it would be now.

Unfortunately from all I read the MT now costs appreciably more to repair than the PDK. The PDK develops electrical problems but the sensors most prone to fail have been reverse engineered. MTs are mechanical things that require old school mechanics with skills to fix them. Good mechanics are hard to find.

groovzilla

Manual Transmissions are tough and robust and rarely have issues. PDK another story.
Would be interesting to count up how many PDK problem Posts/Threads there are on RL but probably take too much time and not sure if anyone can count that high.

Yes there will be an occasional MT issue that may arise but on rare occasion and most likely due to poor previous ownership shifting like animal/poor servicing-not changing fluid/etc

Goose 993

Strange that 6th is grinding. Not really a gear you slam into.