bheit1

According to the service manual the clutch must be flushed separately, even though it shares a reservoir with the brakes.

mikemessi

Aisin makes the gearbox in the 997. They also make Mazda, Toyota/Lexus, and some Honda gearboxes. It is recognized as a very high quality transmission manufacturer. I've read posts on this forum from reputable transmission builders who say it is a very good transmission. The 911 will never shift like an s2000 because the shifter in the s2000 goes directly into the gearbox below it engaging rods connected to the shifter forks. Due to transmission location relative to the shifter the 911 uses cables. Cable shifters are very sensitive to timing. If your shift timing is off it will fight you. Think of whipping the end of a jump rope and the shockwave that propogates down it. This goes both ways. If your clutch disengagement is poorly timed with the gas peddle a shockwave will travel from the other way. Stiff engine mounts help to minimize this. Porsche historically has spaced the ratio between 1st and 2nd pretty tall resulting in a large rpm drop. When babying your engine when it is cold and shifting slow it results in a large rev mismatch. If you keep the revs hanging a little with your right foot it will slip into 2nd like butter. No need to double clutch. Start your shift sequence normally by engaging clutch and getting off the gas. Then immediately get back on the gas slightly to hang the revs then shift directly from 1st to 2nd and release the clutch. Lead with the feet. Then as the engine and gearbox warms up you will gradually move the timing of the footwork and shifter/hand work closer together. When cold if you pull on the shifter at the same time as you push in the clutch it will balk. I used this technique on the older 915 gearbox and it works well for this box also. It's all about the timing. And the timing changes as the hydraulic clutch fluid, transmission fluid, synchros, and cables warm up.

sandwedge

Same for me with my -06 C4S. I'd go as far as to say it was the best manual I've ever had and I had an after market short shift kit installed (B&M from Champion). Made it even better including cold mornings. I could shift that thing with two finger tips with no weird noises or other issues. So looking back at my 997 manual experience before I went to PDK, my guess is that at least some of the problems described here are not related to cable adjustments or oil.

Did the previous owner know how to drive a manual? We'll never know. A lot of people think they know how but should really have an automatic instead. Based on some passenger seat time observations on my part.

Petza914

Some of the differences you feel with 1st and 2nd gear engagement are because those synchros are made of a different material than the ones for 3-6 in order for them to last longer since those are the 2 most used gears. Because they're harder, there's more resistance to engagement. If the transmission only struggles a little when it's cold, I think that's normal - just shift to 2nd very slowly but methodically and you should be fine. If you have issues once it's warm then you have other issues.

The reason motor mounts help improve shifting is because they realign everything the way it was supposed to be - they really don't have anything to do with eliminating slop during the shift as you're not generating significant forces with the gear shift lever through the cables that have plastic ends - it's alignment, that's all.

My 05 C2S wit OEM SSK and PTX fluid shifts perfectly smooth with very little effort. The shift to 2nd is stiffer when the fluid is cold, but I just shift it like I described above and it's fine.

Bruce In Philly

Regarding if a Japanese transmission is good or not is a bit silly. The truth, for us, is not knowable. Aisin, like any vendor, takes a customer's specifications and then builds. We don't know what that interaction was between Porsche and Aisin. Did Porsche give the total design to Aisin including the hardness/type of materials? Did Aisin provide design services? Did Asin put into the transmission what they were contracted for? Who knows?

Regarding my first gear jam and my shifting skills.... I am not going to tell you that I am good.... you would not believe me anyway. I can say that as the original owner of my 2000 Boxster S, I got 197K miles on the original clutch and would have gotten more but for the engine exploding. Fluke? Luck? I dunno. My current thinking is that my 2009 C2S manual transmission is either made with inferior metals or has a design flaw. I have yet another order for PTX... if this stops working, I have no choice, my fault or not, to get the transmission repaired.... I think the thing is slowely wearing out.... new PTX or early changes will prevent the premature wear... so I think.

Peace
Bruce in Philly

Hindsight2010

I don't understand what is getting out of alignment..... Do the cable shifter ends mount to the frame or the transmission body on the 997? If it's the latter, then the transmission could be moved around quite a bit but the alignment of the cable exit to the transmission linkage would remain unchanged, no?

Bruce In Philly

The cables (really flexible rods) are bolted to the transmission just before the attachment to the levers. The cable ends move with the transmission. I changed my rear two rear engine mounts it did nothing for the shifting. (I changed my mounts ... being honest here... simply because I was looking for a project and they were "old".. upon removal, the right one was lower than the left.)

Peace
Bruce in Philly

Hindsight2010

Yeah that's what I thought. Given the cable ends move with the transmission, I don't see how movement of the transmission could result in alignment issues.

Bruce In Philly

Many here claim it does.

Peace
Bruce in Philly

Carreralicious

I once had a bad motor mount in my Boxster to the point where when I turned right and gave it throttle, there would be a grinding noise. Shifting, however, was still butter smooth and unchanged before and after mount change. Never even changed or had to adjust the shift cables or change transmission fluid during the 17 yrs I owned it and it still was butter smooth in operation during all that time.

In my 997.1. i did have a problem of sometimes having a hard time getting into 1st gear at stoplights once in a while and that stopped after I had the clutch slave bled. Not sure if it was related or not, but I did nothing else.

Hula

It's never going to shift as smoothly as an S2000 or a Miata. In those, the shifter sits right above the transmission. It's a straight shot. The 911, or any car with a trans-axle, the shifter needs to reach back with cables.

ATSR

Numeric Racing shifter + Function First cable terminal ends + Rennline semi-solid engine mounts = shifter perfection.

That’s my setup and I couldn’t be happier

Steph1

I'd start with the engine mounts.

TheTorch

Quick update on my 1-2 shift grind when cold.

• As i noted before, changing engine mounts did not do anything to improve this.
• I replaced the transmission fluid today with PTX. Still very slightly balky from first to second when cold, but the grind appears to be gone. Shifts are buttery otherwise, and once warm all good.

PS. PTX smells awful.

Petza914

Who cares what it smells like when it works as well as it does