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UPDATED 1-11-21. I took advantage of Function Firsts Black Friday sale and ordered new engine mounts, cable ends and the Shift Right shifter bushings. I had my Indy install the parts today, and WOW what a difference! See my notes below on each point.
After driving my 997.2 base manual for a few months, I have the following thoughts. For context, I’ve been driving manuals for over 20 years, previously owning a 02 WRX, e46 3 series, and R55 John Cooper Works Mini. Out of these, I loved the Mini’s 6 speed box the most. Bone stock, it was easy to drive, heel toe, short throws, would go into 1st at a roll, never balky even in the freezing cold. Amazing transmission IMO and I never felt the need to mod anything on that car.
The 911 had 45k miles when I purchased, and DME showed it was a cream puff with no revs over zone 1. So the car was not dogged. Compared to my prior Mini, the 911 clutch is longer and stiffer, not surprising given the extra engine power. My non-adjusting base clutch engages towards the top. Not sure whether the clutch is towards the end of life, but it hasn’t slipped yet and engages fairly well. Took some getting used to, but it’s not bad feeling. I suspect a new clutch would feel better, but I’ll wait until this completely goes before swapping.
A few issues. First, I had trouble engaging 1st gear from a complete stop, as many have reported. Typically happened at a red light when I’m first in line and looking like a douche in a 911 who can’t drive his car. I did a PTX fluid change and it helped a lot. Only had it happen one more time afterwards when I was rushing to get into 1st from a stop.
Second, as many have said, 1st to 2nd is quite notchy for the first few cold shifts. I shift very slow to avoid grinding. It’s really like the first 3-4 shifts in the morning and then the box feels nice and smooth. The PTX didn’t do much to help this. I understand this is pretty normal and due to different synchro material in 1st and 2nd. Not a big deal, I just take it easy to start. Once warm, the box is very smooth with a rifle bolt feel.
UPDATED 1-11-21 —the Function First cables and bushings make a nice difference. The first few shifts from cold are still slightly notchy but there is much less play and I feel more confident sliding the gear from first to second now. Whereas before, there was a good deal of lateral play, and I worried whether it was going into second gear correctly. Much improved! Overall, I really like this upgrade. Shifts are smoother and firmer, more rifle bolt feeling. I feel more confident when heel toeing and rev matching because I’m more confident I will be able to select the appropriate gear. Highly recommended!
Third, I get a thump in the rear when shifting slowly from 1-2 and 2-3. It took a few months of driving, but I can finally mostly drive without thumping. If I’m accelerating slowly in the neighborhood, I push the clutch in a bit slower and blip the throttle to rev match. The revs drop very quickly on the 911. All my prior manuals would hang the revs slightly after depressing the clutch, so this was a change for me to have to blip while upshifting. Also, if I depress the clutch too quickly while accelerating slow, it will thump. It’s kind of a dance to synchronize everything to avoid thumping, but I suppose it’s the challenge of driving a 911? For the record, I took it to a dealer and my Porsche Indy and they said this thumping was normal on a 997, and even some manual 991s do it.
UPDATED 1-11-21. The FF engine mounts cured the thumping, I am beyond thrilled, as this was my biggest gripe! The mounts add a slight bit more vibration at cold idle, but not too bad or annoying. The engine also has a deeper growl, as the vibrations through the rev range can be heard more. But it’s a nice bit of extra noise, almost as if I had a slight exhaust upgrade. I’m running Fisters and stock center muffler. This has IMMENSELY improved my driving experience, as the thumping is really annoying.
Lastly, the stock 911 pedals aren’t great for heel toeing. I have wide size 12 feet, so on past cars I’ve been easily able to blip the throttle using the right side of the ball of my foot, while keeping the left side in the brake pedal. The 911’s brake and gas pedals are pretty far apart and the gas pedal sits a lot lower. I can heel toe with effort, but it’s not easy. I’ll try a bit longer to see if it gets easier. If not, I may splurge for the Numeric pedals.
A few questions, would a semi sold motor mount and/or tranny mount help with any of these issues? Also, while I’m not interested in a shorter throw, I’m wondering if Numeric cables and short shifter could improve the shift quality. Any thoughts from folks?
I have a 997.1S, so maybe not same situation as you, but I think if your clutch doesn’t bite until the pedal is almost all the way back up, it’s probably worn, as that’s the way my clutch felt in my Boxster when it started slipping at 73k miles. On my 997, the bite is only an inch or two after I let up on the pedal (very low), and I’m at 34k miles now. But if you’re not getting any slip yet, just keep driving. It may be like that for a long time before it’s all worn out.
A lot of folks have had the intermittent problem of not being able to get into first at a stoplight. Some say change the gear oil or adjust your shift linkage. Who knows. I get it once in a while too, and just throw it into 2nd before going back to 1st in those situations, and it goes in. I never get any sort of thumping that you’re describing, so perhaps that is a worn motor mount or tranny mount? When I do replace, I’m just going to go with the stock mounts as I don’t want a stiffer ride.
Agree with Carreralicious on all accounts - I have same car, same miles, same complaints on transmission being notchy. Sounds like your clutch is getting close to the end, i.e., clutch gets stiffer. The thumping does not sound normal - my car is stock with original mounts and I do not have any thumping - usual suspects are the mounts.
997.2 has a self adjusting clutch on both C2 base and C2S. 997.1 was just the s. My C2 base 997.2 has always engaged higher in the throw than my neighbor's 997.1 C2S. I would think worn engine mounts would cause more problems when getting on it rather than driving slow.
1st gear at a stoplight is notchy if rushed. Push the clutch in and count to 2 and it slips in like butter every time. When cold I double clutch and hold the revs up and eliminates notchy 1-2 shift. The quick rev drop of these engines helps for quick shifts when warm but hinders slow cold shifting.
The manual in my 2000 Boxster S (same as in the 911s) was better. But, it was quirky too.
I think the manual in our 997.2 is a drop in Porsche standards. I don't know if they just spec'd cheaper metals or what, but it is not as good as the last one I had... just is not. Total speculation, but I think Porsche made a decision to get out of the manual business, purposfuly took their eye off the ball, and outsourced the manufacture to Aisin a Japanese company. It is a sunset product.
My recommendation is to change the PTX fluid every 25-30k miles... I base this on the time from a change to when I start getting really annoyed.... no science here but I believe that if I did this from the start, the transmission would be much better overall.
I think your clunking when driving slow is related to the quick rev drop and rev mismatch not motor mounts. This gearbox rewards precise throttle control. Hang the revs a little.
Good to know that the 997.2 base has a self adjusting clutch thanks. Yeah I was thinking of changing the engine mounts to see if that makes any difference on the thumping. I have 2 years of CPO warranty so I’m just going to see how it goes. I’m getting used to matching revs to avoid the thump so it doesn’t bother me as much anymore. When I’m accelerating hard to redline, it doesn’t thump as much because the revs are matched well, I think.
Originally Posted by mikemessi
997.2 has a self adjusting clutch on both C2 base and C2S. 997.1 was just the s. My C2 base 997.2 has always engaged higher in the throw than my neighbor's 997.1 C2S. I would think worn engine mounts would cause more problems when getting on it rather than driving slow.
For the shifting, maybe go with the shifter first, and then add the cables and see if it gets you there. I have the Numeric shifter, but no cables. No real notchyness going 1-2. I do have occasional problems shifting into first like you mentioned but still need to do the PTX fluid change.
As for the heel-toe’ing with the stock pedals... totally agree. I took Bruce in Philly’s advice and got the rennline set up which includes the pedal, the lifter plate, and the extensions. The lifter plate is very adjustable and you can dial in height and angle. At that point you may or may not want to use the extensions once the gas pedal gets lifted up to an easier height for heel toeing. I personally use the extensions. It’s made heel toeing an afterthought now! Bruce also has a really excellent write up on this forum how to install it and the various trials and tribulations he went through, worth a read!
Edit: Didn’t see Bruce had already weighed in and posted the link. Straight from the horses mouth!
Yes I agree with this rev mismatch thought. The 997.2 engine drops revs quicker than any car I’ve driven, which is a good thing I guess? I remember my old 02 WRX used to hold revs pretty badly, for emissions purposes if I recall correctly.
Originally Posted by mikemessi
I think your clunking when driving slow is related to the quick rev drop and rev mismatch not motor mounts. This gearbox rewards precise throttle control. Hang the revs a little.
Thanks Bruce. I saw your Rennline post and may try the same at some point. I’m just not keen on having mismatched pedals so I was looking at the new Numeric set. I was going to see if I can get used to the stock pedals first though.
The Aisin box does seem a bit iffy. I really loved the Getrag box on the JCW. I never missed a shift and could heel toe and rev match without a second thought. I’m still getting used to the 911 and hope that I’ll get better with this manual. It’s taking more work than I expected but I’m enjoying the learning process.
Originally Posted by Bruce In Philly
2009 C2S 164K miles
The manual in my 2000 Boxster S (same as in the 911s) was better. But, it was quirky too.
I think the manual in our 997.2 is a drop in Porsche standards. I don't know if they just spec'd cheaper metals or what, but it is not as good as the last one I had... just is not. Total speculation, but I think Porsche made a decision to get out of the manual business, purposfuly took their eye off the ball, and outsourced the manufacture to Aisin a Japanese company. It is a sunset product.
My recommendation is to change the PTX fluid every 25-30k miles... I base this on the time from a change to when I start getting really annoyed.... no science here but I believe that if I did this from the start, the transmission would be much better overall.
Thanks Bruce. I saw your Rennline post and may try the same at some point. I’m just not keen on having mismatched pedals so I was looking at the new Numeric set. I was going to see if I can get used to the stock pedals first though.
The Aisin box does seem a bit iffy. I really loved the Getrag box on the JCW. I never missed a shift and could heel toe and rev match without a second thought. I’m still getting used to the 911 and hope that I’ll get better with this manual. It’s taking more work than I expected but I’m enjoying the learning process.
Rennline makes matching brake, clutch, and dead pedal too so you can round out the full set.
I had that same thumping in my 997.1 C2S when releasing the clutch at slow speed in traffic. I already had the RSS semi solid mounts, so knew it wasn't motor mounts, but what I did find is the the foam isolators that are part of the transmission mounts just disintegrated in my hand. The primary transmisison mount was still in good shape without any tears in the rubber, so while I had my car on the lift for the engine work I was doing over multiple months, I installed the Function First Transmission Mount inserts. I went with the orange soft ones as stiff transmission mounts can transmit a lot of gear whine and vibration to the cabin and chassis and with the solid mounts in my 928 because of the Corvertte Z06 6-speed I have in that, knew I didn't want that in my 997.
Close up of the OEM transmission mount bushing. If there are cracks connecting the designed gaps, you need to replace the mount bushing before installing the FF inserts. Mine were fine. Note how the side foam pads are completely gone.
Another pic with the mounting bracket out of the way - cleaned up and ready for install off the FF inserts
With a 4-post lift and high-lift transmission jack, the job is really easy
FF Inserts Installed. Note the side isolators - the OEM mount had soft foam versions here, but even at 60k miles, mine were completely shot.
I used a silicone grease to lubricate the FF inserts so they would mate well with the OEM bushing when installed.
As far as I can tell, this seems to have addressed the thumping noise. I still have a noise back there, but it's different and think it's a worn suspension top mount, so my next repair will to install Tarret Momoball top mounts back there like I have in the front, which will remove the last bits of rubber bushings from my suspension.
Anyway, the FF inserts are great - they mate with the original mount bushing to give it extra support and stiffness and control any motion back there.
My car has the OEM SSK and fresh PTX in it. I get the stiff 1 > 2 shift in the morning, but just do it slowly and deliberately as you do and it's because 1st and 2nd have different synchro ring material, like you mention. Once warmed up, it's not a problem at all. I hardly ever have a problem going straight to 1st at a light, and if I feel any resistance, like Carreralicious does, I pop down into 2nd to stop the trans shafts from spinning and then it goes right into 1st. If you don't have a SSK, I'd recommend you install one as it really tightens up the shifting - the Numeric is probably the one to get, but my OEM one works great too, so not worth the time to swap it for something else. I will install numeric cables that I already have in the parts cabinet should I ever have a cable failure. The other thing that might help is the OEM cables can pop out of their mounts underneath the car. Make sure yours are snapped it and then wire tie them into that position. When they pop out, they create just enough slop as the move and flex where the shifting gets just sloppy enough to notice it doesn't feel precise.
11-22-2020, 01:54 PM
Thoughts on the 997.2 manual transmission
