Manual transmission shift question

[silotwo]

I am trying to confirm whether or not it is considered "normal" to hear and feel synchronizers grinding when shifting aggressively at 5500+ RPM. My 04 996 C2 6 spd with 26k miles demonstrates this consistently when grabbing 4th from 3rd. No problem at lower revs or at top revs when I shift slowly. Porsche tech test drove the car and witnessed it at his own hands. He said it was not normal but blamed worn shifter bushings. So, I purchased an OEM short shift kit and had it installed today. (Dealer offered to intall the shifter at no cost under CPO warranty if I bought the part, couldn't pass that up) Shifter works great but it didn't fix the problem.

I spoke to a parts guy at a different Porsche dealer and his answer was "oh yeah" they all do that when you are driving aggressively.

Can anyone tell me whether or not this is normal?

Thanks much

[wwest]

I am trying to confirm whether or not it is considered "normal" to hear and feel synchronizers grinding when shifting aggressively at 5500+ RPM. My 04 996 C2 6 spd with 26k miles demonstrates this consistently when grabbing 4th from 3rd. No problem at lower revs or at top revs when I shift slowly. Porsche tech test drove the car and witnessed it at his own hands. He said it was not normal but blamed worn shifter bushings. So, I purchased an OEM short shift kit and had it installed today. (Dealer offered to intall the shifter at no cost under CPO warranty if I bought the part, couldn't pass that up) Shifter works great but it didn't fix the problem.

I spoke to a parts guy at a different Porsche dealer and his answer was "oh yeah" they all do that when you are driving aggressively.

Can anyone tell me whether or not this is normal?

Thanks much

We need a better definition of what you consider "aggressive"....

I suspect that most any of us can "over-run" the synchronizers if we really tried.

I can't imagine how a short shift kit would help in this case, hindrance maybe.

Oh, be careful who you tell this story to, dealer may have inadvertently voided your CPO by billing the labor for "unauthorized" work.

[Edgy01]

I am trying to confirm whether or not it is considered "normal" to hear and feel synchronizers grinding when shifting aggressively at 5500+ RPM. My 04 996 C2 6 spd with 26k miles demonstrates this consistently when grabbing 4th from 3rd. No problem at lower revs or at top revs when I shift slowly. Porsche tech test drove the car and witnessed it at his own hands. He said it was not normal but blamed worn shifter bushings. So, I purchased an OEM short shift kit and had it installed today. (Dealer offered to intall the shifter at no cost under CPO warranty if I bought the part, couldn't pass that up) Shifter works great but it didn't fix the problem.

I spoke to a parts guy at a different Porsche dealer and his answer was "oh yeah" they all do that when you are driving aggressively.

Can anyone tell me whether or not this is normal?

Thanks much

I'm going to make a few observations from the limited information you provided. First of all, Porsche transmissions are robust but they should not be abused. I'm guessing that this is a used Porsche that you purchased, so you can't say how abusive the other owner(s) were. They may have contributed to this. I have several hundred thousand miles in Porsches (mostly 911s) and never had to replace a synchro. It may be someone's style of driving. Installing a short shift kit will only make this worse. What a short shift does which you must know is to reduce the distances needed to move the stick from one gear to the next. The time it takes to make that shorter move is thus less, and hence the quicker shift. However, synchros take a certain amount of time to synchronize. When you shortcut that time with a short-shifter you are automatically going to challenge those synchros even more. This is not a good thing. Frankly, I'm surprised your dealer offered to do that installation under their dime,--they are only trying to sell parts. They are not interested in solving your problem. Not knowing how synchros works is unacceptable from a dealership.

The only way to know what 'aggressive' is for you is to see you drive it. For them to be in that shape by 26,000 miles is absolutely abuse. I have had a couple of 911s well over 100,000 miles (of my driving) and they never had a problem with synchros.

Dan

Edited September 14, 2007 by Edgy01

[Izzy]

I agree with Dan. I have the same bad habit, trying to shift gears like a GT driver. And I get grinding into 3rd. The synchros do take time to "synchro" when you depress the clutch. A few weeks ago at a VIR DE event, watching an onboard video with some guys, a former owner of a Porsche dealership commented on how fast the driver was shifting, and how much money he used to make with problem transmissions from guys who did that.

I took notice and started shifting a bit slower, it may add a second to my lap time overall, but it does "feel" a bit better to clutch-in, pause, change gear, accelerate and release clutch.

Just my opinion, don't want to offend any racers out there.

[1999Porsche911]

There should be no grinding of any gear on an upshift, no matter how fast and hard you shift. If there is grinding, you have a problem, either with the disengagement of the clutch or the transmission or just not knowing how to shift properly. Those who say it is normal are living in denial or maybe just looking to justify their problem by finding others with the same.

Your car should be under warranty and I would demand that the problem be corrected.

Edited September 14, 2007 by 1999Porsche911

[silotwo]

First, thank you for the responses. Yes, I purchased the 04 996 C2 used with 24,500 miles from a local Porsche dealer. By aggressive, I mean rev to 5500 to 6800, clutch full in while off throttle and shifting from third to fourth as quickly as I can. Picture a 1/4 mile run but absolutely no flat shifting. The issue is only 3rd to 4th and only on an upshift. Conversely, I can quickly ramp to 4500 rpm in 3rd gear and grab 4th with everything I have and no grinding what so ever.

I have been assertive, but not abrasive or abusive, with the dealer. My bottom line is that I paid what I believe to be fair market value, 53k for a supposed Porsche Certified vehichle that is both under original warranty as well as CPO warranty. The car is optioned to suit me, PSE, MO30, PSM,power and heated seats, bose upgraded stereo, 18" carrera wheels, flared rocker panels.

The tech was so adament about it being the shifter that I opted to "go along" rather than argue with him. I was interested in the short shifter from the beginning (bought it from a different Porsche dealer for 30% less than the selling dealer). My approach was that if it didn't work, as I strongly suspected it wouldn't, I'd be taking that excuse away from them. I am following up with the dealer and will insist that the car be made right.

I am not going to track the car and although I did not plan on this, it has become my daily driver. I do not typically run any car to the edge on a routine basis. I understand that we have precision machines and like any mechanical item we will break 'em if we beat 'em. The only reason I put the car through it's paces was to shake it out while under warranty. 20/20 hindsight, maybe I should have done that during the weekend test drive, but at that point it wasn't my car, and I still hold on to respecting property, especially when it doesn't belong to me.

Way back in the day I had a 1968 911L with the sportomatic. I sold it to my uncle and his youngest son still has it. It was a self promise to "some day" own another 911 and I guess some day just arrived. LOL - my three boys used to look at the picture of that polar white 911 I keep in the family room and ask "Dad, don't you wish you still had that car?" I'd say "yes, I sure do, but you guys are my Porsche now". And today I have the three boys AND a Porsche. :) some days life is just good.

[1999Porsche911]

I would demand that they fix the problem, whether it need a new tranny or whatever. Powertrain warranty should cover it. It will only get worse. You should be able to bounce of the rev limiter into the next gear with no grinding or noise at all.

[silotwo]

I would demand that they fix the problem, whether it need a new tranny or whatever. Powertrain warranty should cover it. It will only get worse. You should be able to bounce of the rev limiter into the next gear with no grinding or noise at all.

Thanks. And I have another somewhat related question about clutch pedal travel. The dealer claims that they replaced the clutch disc when they replaced the RMS at 24,200k. I don't experience any slippage but the pedal travel to point of engagement seems to vary. At times it engages close to off the floor, but at most times it seems to engage at about midpoint or higher to full release. It does not require pedal to the floor for shifting at most times. They did flush and fill the hydraulic fluid, which I understand is the same system for both clutch and brakes. Fluid level is stable. Again I am wondering if this is "normal".

I really appreciate the information.

Thanks

John

[1999Porsche911]

I would demand that they fix the problem, whether it need a new tranny or whatever. Powertrain warranty should cover it. It will only get worse. You should be able to bounce of the rev limiter into the next gear with no grinding or noise at all.

Thanks. And I have another somewhat related question about clutch pedal travel. The dealer claims that they replaced the clutch disc when they replaced the RMS at 24,200k. I don't experience any slippage but the pedal travel to point of engagement seems to vary. At times it engages close to off the floor, but at most times it seems to engage at about midpoint or higher to full release. It does not require pedal to the floor for shifting at most times. They did flush and fill the hydraulic fluid, which I understand is the same system for both clutch and brakes. Fluid level is stable. Again I am wondering if this is "normal".

I really appreciate the information.

Thanks

John

Make sure it is not your imagination. However, the engagement point should be at the same point in the pedal's travel, each and every time. If not, your hydraulic lines may be flexing or it may be a bad or loose clutch slave or even a bad actuator lever. This asumes that the system is properly bled.

Edited September 15, 2007 by 1999Porsche911

[silotwo]

Thanks Izzy. I agree about putting my imagination in check. Here is what I have noticed to be consistent. First ride of the day the clutch engages close to the floor, with in a few shifts it engages noticeably higher. The part I am still trying to confirm as real is it seems that the longer I sit with the clutch pedal fully depressed, the closer it engages off the floor. Given the poor service advice I have been given by the selling dealer, I wouldn't doubt that they failed to correctly bleed the system when they "flushed and refilled brake fluid". Is there anything I can do, as a test of sorts, to confirm that the pedal travel does vary. Like in the old days, pumping the brakes and getting a firmer pedal was a good indication that excessive air was in the system.

I obviously need to have another dealer check this car out.

[wvicary]

I would suspect that maybe the clutch master cylinder is bypassing internally and not disengaging the clutch at times. This would explain the different engagement points.

[Izzy]

If you decide to do it yourself, it is fairly simple to do with a pressure bleeder. These guys have a good price on them right now.

http://www.apexperformance.net/cartgenie/p...ist.asp?scat=26

The instructions on how to bleed are on the DIY section. You could get that variable out of the equation and see what else is going on. However, if you are like me, I am always wondering "does the clutch feel lighter today?" "Do the brakes feel looser than last trip" etc, etc. Take it to dealer and everything is fine, so sometimes it is my head as a "car maintenance hypocondriac"

[silotwo]

If you decide to do it yourself, it is fairly simple to do with a pressure bleeder. These guys have a good price on them right now.

http://www.apexperformance.net/cartgenie/p...ist.asp?scat=26

The instructions on how to bleed are on the DIY section. You could get that variable out of the equation and see what else is going on. However, if you are like me, I am always wondering "does the clutch feel lighter today?" "Do the brakes feel looser than last trip" etc, etc. Take it to dealer and everything is fine, so sometimes it is my head as a "car maintenance hypocondriac"

Finally had the service writer return my call today about the grinding. Now it is "stop by and take the service manager for a drive". I already "stopped by and took the Porsche Tech for a drive" He drove the car and experienced the same grind that I did. Now I am wondering why they would be so hesitant to just make it right considering that it is under warranty. I'll post the outcome after the service writer renders his opinion.

Edited September 19, 2007 by silotwo

[silotwo]

If you decide to do it yourself, it is fairly simple to do with a pressure bleeder. These guys have a good price on them right now.

http://www.apexperformance.net/cartgenie/p...ist.asp?scat=26

The instructions on how to bleed are on the DIY section. You could get that variable out of the equation and see what else is going on. However, if you are like me, I am always wondering "does the clutch feel lighter today?" "Do the brakes feel looser than last trip" etc, etc. Take it to dealer and everything is fine, so sometimes it is my head as a "car maintenance hypocondriac"

Finally had the service writer return my call today about the grinding. Now it is "stop by and take the service manager for a drive". I already "stopped by and took the Porsche Tech for a drive" He drove the car and experienced the same grind that I did. Now I am wondering why they would be so hesitant to just make it right considering that it is under warranty. I'll post the outcome after the service writer renders his opinion.

Just got back from the dealer and the service manager drove the car and his reaponse was, finally, "needs a fourth gear synchro". First few shifts he was really slow, actually let the shifter sit in the neutral gate before easing it into 4th. All the while he is telling me how this is a Porsche and not a big block chevy and how small the clutch disc is on a Porsche and blah blah blah. Finally I said "I get that" and asked him to "please shift the car at over 5,000 rpm and shift it in a spirited manner". So he ramped it up and grabbed 4th and immediately made the statement about needing a 4th gear synchro. All covered by warranty.

So now, if I can bother you guys some more I am interested in your opinion as to whether or not I should invest in a new pressure plate and release bearing while they have the tranny out. They did produce the record for installing a new clutch disc when they did the RMS, so that should be fine. Car now has 26,500 miles on it. Will appreciate any thoughts you have.

Thanks much