subtle transmission grind
07-18-2018, 02:38 PM
#16
Instructor
I've had the same problem - slight (and brief) but noticeable grinding sound when shifting from 4th to 5th only. All other gears are fine. It also only happens when cold. I live about 10 mins from highway so I'm in 3rd all the way there, then a quick jump to 4th and then to 5th. That's when I hear (and feel) it. After it warms up though it always goes away.
We just did an 800-mile road trip with many shifts and it happened only once when we left the house, not even when we began our return trip. (I did get a flat tire, but that's for another thread!)
Funny thing is it wasn't doing anything for the first 3 years I owned it, then it started earlier this year. I looked back at the PPI paperwork and saw that the mechanic had detected it while road testing ("Possible synchro problem") but we both agreed it wasn't that serious. Now with 65K miles it's occasionally happening again. I did have the transmission oil changed a few months ago and that seems to have helped.
It's rare enough that I can live with it, and doesn't seem to ever get worse. If it does, well... that would be troublesome.
We just did an 800-mile road trip with many shifts and it happened only once when we left the house, not even when we began our return trip. (I did get a flat tire, but that's for another thread!)
Funny thing is it wasn't doing anything for the first 3 years I owned it, then it started earlier this year. I looked back at the PPI paperwork and saw that the mechanic had detected it while road testing ("Possible synchro problem") but we both agreed it wasn't that serious. Now with 65K miles it's occasionally happening again. I did have the transmission oil changed a few months ago and that seems to have helped.
It's rare enough that I can live with it, and doesn't seem to ever get worse. If it does, well... that would be troublesome.
07-18-2018, 09:36 PM
#17
Racer
Happens on mine too, on the 4th to 5th shift only when it's cold. Once everything warms up its perfectly smooth in all gears. Transmission flush didn't help, neither did putting the alignment tool on and readjusting the cables.
Discussed with my indy that we're not about to drop the transmission for this until I need a clutch. So I've learned to just live with it, stay in 4th until it's warm to avoid it!
Discussed with my indy that we're not about to drop the transmission for this until I need a clutch. So I've learned to just live with it, stay in 4th until it's warm to avoid it!
07-19-2018, 08:36 AM
#18
Rennlist Member
It’s unlikely that so many of these cars would have worn synchros or some other failure, and instead, might just be a design issue. So I wouldn’t worry about it at this point.
07-20-2018, 03:23 AM
#19
Nordschleife Master
Doubt it. Put 45,000 miles on my 6sp -06 C4S and never had a any issues like those described here. Yes it's a Florida car but we have cold mornings here too now and then during the winter months. Never a problem no matter what the outside temperature was and I owned that car for three years.
07-20-2018, 09:50 AM
#20
RL Community Team
Rennlist Member
Rennlist Member
None of the gears in either of my 997s grind. One has 55,000 miles and the other 105,000 miles. Both got fresh Mobillube PTX about 5,000 miles ago. They are stiff to shift into 1st and 2nd when cold, but even when stiff there is never any grinding.
07-20-2018, 10:08 AM
#21
Track Day
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Over the last 2 mornings, I’ve gone for “test drives” where I’ve intentionally stayed in 4th gear for about 10 minutes to let the car warm up more. Both times I was able to shift to 5th & 6th with no grinding. During both test drives, I shifted into and out of 5th and 6th gear numerous times with no issues. Based on this, I’ll be intentional to let the car warm up more but still keep an eye on it in case it gets worse. Not quite time for a fluid change yet, but will do that in about 5k more miles.
07-20-2018, 11:25 AM
#22
Both my 997.2 and my 996.2 had (and continue to have) mild grinding into 2nd. I suppose the severity goes from mild to very mild after it warms up, but I've never understood why car reviewers always praise the Porsche 6 speed manual... my Jetta shifts WAY smoother. (yes yes, I know, PTX, Numeric, cables etc etc, but they praise the factory setup). I have the FF cable ends which certainly help, but not the grinding. I'm still looking for PTX locally. The Numeric shifter is laughably expensive. End rant.
07-20-2018, 03:35 PM
#23
Rennlist Member
Doubt it. Put 45,000 miles on my 6sp -06 C4S and never had a any issues like those described here. Yes it's a Florida car but we have cold mornings here too now and then during the winter months. Never a problem no matter what the outside temperature was and I owned that car for three years.
07-20-2018, 03:40 PM
#24
Rennlist Member
However, I’m wonder if reviewers just like the feel, even if it’s not perfectly smooth.
07-20-2018, 03:50 PM
#25
Three Wheelin'
I have a similar issue in my 997.1 with 60k miles. I hear from time to time a slight grind from 4th to 5th on first shift of the day. Doesn't seem to be 100% correlated to engine temp. My oil temp can already be at 200 by the time I get to the highway and still hear it my first shift into 5th on the highway. I heard it one day with my windows down driving next a medium and it definitely caught my attention.
I do feel some of these occasions have been user error where I was too slow on the shift and too fast on the clutch. I made a mental note a while back to be more deliberate in my high gear shifts. This post reminded me to try this for a week or two and see if that does anything.
I do feel some of these occasions have been user error where I was too slow on the shift and too fast on the clutch. I made a mental note a while back to be more deliberate in my high gear shifts. This post reminded me to try this for a week or two and see if that does anything.
07-20-2018, 03:59 PM
#26
I know there are ways to be extra careful with the 4-5 shift for the first gear change cold and then its fine. But if you've got 30-40k on your fluid you really owe it to yourself to get some PTX in there as soon as you can.
07-21-2018, 01:12 AM
#27
Nordschleife Master
I would never expect a 997 to shift like a Ford wagon or any other common family car. It is a sports car with two to three times the HP of those so the transmission obviously needs to be more robust. That said, I will always say that the 6sp in my -06 C4S was the best manual I've driven over the years and I'm no youngster anymore. I actually think it got even better when I added the short shift kit. Could easily shift that thing through all the gears using two finger tips even when cold. Adjusting the cables just right may play a bigger role than we think. My dealership has 4 Porsche certified master technicians and they have all told me that even small adjustments in the cable linkage can make a big difference. The guy who's considered the best of those four is the one who installed the SSK in my C4S and he told me it took 4 tweaks and as many test drives before he was happy with the result which was absolute perfection.