Third Gear Noise '99 996 C2 - Any ideas?

[chriswaxman]

Hello all -

I have a '99 C2 Coupe, 6-speed manual, US Model, 44k miles. Just today I noticed a new and disconcerting noise. When in third gear AND the gas pedal is pressed there is a quite noticeable rattling/whirring noise emanating from what I believe is the transmission. (Describing it as "grinding" would be going too far.) Again, it is only in third and only when the accelerator is pressed, not when coasting. There does not appear to be an issue when in any of the other gears.

I'm the third owner of the car and I've put on nearly 1/3 of the 44k within the last year. In other words, it went from being a sunny Sunday garage queen with others to my daily driver. No other issues with the car at all.

I have a few ideas but would appreciate hearing what anyone else has to say on the matter.

Also, any recommendations for an independent Porsche shop in or around Philadelphia would be appreciated. Someone who could both diagnose and repair. I live in Philadelphia and work in the western suburbs.

Finally, if the issue is something inside the transmission, is it common to have internal work done with discreet internal parts replaced, or are we talking rebuilt transmission, send the core in, etc.?

Thanks

Edited June 8, 2009 by chriswaxman

[Benjamin Choi]

Finally, if the issue is something inside the transmission, is it common to have internal work done with discreet internal parts replaced, or are we talking rebuilt transmission, send the core in, etc.?

Thanks

I believe the tranny like the engine must be replaced as Porsche supplies 0 individual parts for both engine and tranny thus rebuilt engines, rebuilt trannys from the factory as whole units.

:( I think a new tranny costs nearly as much as a rebuilt engine?

[Loren]

Porsche started supplying individual parts for 9x6 series transmissions about 2 years ago.

Most engine parts have always been available.

[chriswaxman]

The car is at a respected local independent as of this morning, awaiting diagnosis. The independent said, as Loren did, that parts are now available from Porsche for transmission repair.

Apparently some specialists have been repairing 996 transmission for years before Porsche made parts available by going to the suppliers used by Porsche.

Shopping around it seems a good rebuilt transmission can be bought for about $3000 w/core exchange. A huge hit, to be sure. :( But about 1/2 of a new motor, fwiw. Let's hope it doesn't come to that. If it does come to that, from what I've seen the US rebuilders of 996 transmissions make some nice upgrades for 1/2 the price of a Porsche-supplied replacement. But like I said. . . let's hope it doesn't come to that!

Searching the web it seems like 996 transmission issues are rare and the ones that crop up usually relate to 2d gear. I was hoping my post would shake out some experiences with transmission bearings, thrust washers, main shaft, etc. But for the sake of all of us, maybe its better that the information isn't out there!

[c70Pete]

The car is at a respected local independent as of this morning, awaiting diagnosis. The independent said, as Loren did, that parts are now available from Porsche for transmission repair.

Apparently some specialists have been repairing 996 transmission for years before Porsche made parts available by going to the suppliers used by Porsche.

Shopping around it seems a good rebuilt transmission can be bought for about $3000 w/core exchange. A huge hit, to be sure. :( But about 1/2 of a new motor, fwiw. Let's hope it doesn't come to that. If it does come to that, from what I've seen the US rebuilders of 996 transmissions make some nice upgrades for 1/2 the price of a Porsche-supplied replacement. But like I said. . . let's hope it doesn't come to that!

Searching the web it seems like 996 transmission issues are rare and the ones that crop up usually relate to 2d gear. I was hoping my post would shake out some experiences with transmission bearings, thrust washers, main shaft, etc. But for the sake of all of us, maybe its better that the information isn't out there!

996 transmission issues are not rare... especially @ 60K miles and beyond... pinion bearings.. whiring/whining; gears popping out and crunchy shifts... lots of cars suffer from these symptoms... I believe 996 use brass synchros and there are a lot of shops out there who replace tranny fluid with synthetic thinking it is a superior fluid... fact of the matter is that brass and synthetic don't mix... you cause damage... there is a great video I found that illustrates the failures of 996 transmissions and what typically fails... the synchros are just one part... there are spider gears that fail and of course the bearings....

[phillipj]

So Pete,

What gear oil do you use for your Tranny? I'm going to change mine and I'm looking for some input (Besides the Mobil 1 Delvac.)

Thanks!

[c70Pete]

So Pete,

What gear oil do you use for your Tranny? I'm going to change mine and I'm looking for some input (Besides the Mobil 1 Delvac.)

Thanks!

I used the stock one from the dealer as specified for our cars... if your tracking your car just change it every year... if not then every 2-3 years should be fine (still well before what porsche recommends but its a lot cheaper than a new tranny!!)

in the end these transmissions are prone to failure because of their cheap internal parts that are self-lubricating bearings that fail over time especially when tracked and used hard...

[phillipj]

So the dealer reco is not a synthetic?

[c70Pete]

So the dealer reco is not a synthetic?

whatever the dealer gives you is good for your car... it has the proper friction modifiers that the transmission requires... I believe the gear oil for 996 C2 is non-synthetic...

[phillipj]

Thanks Pete

[SH-GT3]

As a Contributing member, you have access to the TSBs.

See this one for info on Transmission Oils

996_3_29_08_Approved_Oils.pdf

Edited June 9, 2009 by Anders0n||C4S

[chriswaxman]

996 transmission issues are not rare... especially @ 60K miles and beyond... pinion bearings.. whiring/whining; gears popping out and crunchy shifts... lots of cars suffer from these symptoms... I believe 996 use brass synchros and there are a lot of shops out there who replace tranny fluid with synthetic thinking it is a superior fluid... fact of the matter is that brass and synthetic don't mix... you cause damage... there is a great video I found that illustrates the failures of 996 transmissions and what typically fails... the synchros are just one part... there are spider gears that fail and of course the bearings....

I hear you about synthetic being bad for certain transmissions. I had that happen to a Saab 900S. A mechanic crowed about how great it was that he put synthetic oil in the transmission. Bascially ruined the transmission. He later dumped the synthetic and put in dino but was never quite the same and eventually the transmission was replaced. Ironically the guy runs a Saab specialty shop and Saab says quite explicitly not to use synthetic gear oil.

I don't know what gear oil is in my 996, but I'm guessing its what was put in at the factory as the car only has 44k on it.

Edited June 9, 2009 by chriswaxman

[Benjamin Choi]

The car is at a respected local independent as of this morning, awaiting diagnosis. The independent said, as Loren did, that parts are now available from Porsche for transmission repair.

Apparently some specialists have been repairing 996 transmission for years before Porsche made parts available by going to the suppliers used by Porsche.

Shopping around it seems a good rebuilt transmission can be bought for about $3000 w/core exchange. A huge hit, to be sure. :( But about 1/2 of a new motor, fwiw. Let's hope it doesn't come to that. If it does come to that, from what I've seen the US rebuilders of 996 transmissions make some nice upgrades for 1/2 the price of a Porsche-supplied replacement. But like I said. . . let's hope it doesn't come to that!

Searching the web it seems like 996 transmission issues are rare and the ones that crop up usually relate to 2d gear. I was hoping my post would shake out some experiences with transmission bearings, thrust washers, main shaft, etc. But for the sake of all of us, maybe its better that the information isn't out there!

996 transmission issues are not rare... especially @ 60K miles and beyond... pinion bearings.. whiring/whining; gears popping out and crunchy shifts... lots of cars suffer from these symptoms... I believe 996 use brass synchros and there are a lot of shops out there who replace tranny fluid with synthetic thinking it is a superior fluid... fact of the matter is that brass and synthetic don't mix... you cause damage... there is a great video I found that illustrates the failures of 996 transmissions and what typically fails... the synchros are just one part... there are spider gears that fail and of course the bearings....

If 996 tranny issues are not rare and I rarely hear about them posted on 911 forums, then given the frequency of engine failures we ALL read online, the whole M9X engine program has got to be an absolute engineering joke!

[c70Pete]

The car is at a respected local independent as of this morning, awaiting diagnosis. The independent said, as Loren did, that parts are now available from Porsche for transmission repair.

Apparently some specialists have been repairing 996 transmission for years before Porsche made parts available by going to the suppliers used by Porsche.

Shopping around it seems a good rebuilt transmission can be bought for about $3000 w/core exchange. A huge hit, to be sure. :( But about 1/2 of a new motor, fwiw. Let's hope it doesn't come to that. If it does come to that, from what I've seen the US rebuilders of 996 transmissions make some nice upgrades for 1/2 the price of a Porsche-supplied replacement. But like I said. . . let's hope it doesn't come to that!

Searching the web it seems like 996 transmission issues are rare and the ones that crop up usually relate to 2d gear. I was hoping my post would shake out some experiences with transmission bearings, thrust washers, main shaft, etc. But for the sake of all of us, maybe its better that the information isn't out there!

996 transmission issues are not rare... especially @ 60K miles and beyond... pinion bearings.. whiring/whining; gears popping out and crunchy shifts... lots of cars suffer from these symptoms... I believe 996 use brass synchros and there are a lot of shops out there who replace tranny fluid with synthetic thinking it is a superior fluid... fact of the matter is that brass and synthetic don't mix... you cause damage... there is a great video I found that illustrates the failures of 996 transmissions and what typically fails... the synchros are just one part... there are spider gears that fail and of course the bearings....

If 996 tranny issues are not rare and I rarely hear about them posted on 911 forums, then given the frequency of engine failures we ALL read online, the whole M9X engine program has got to be an absolute engineering joke!

You need to listen more carefully then cause this year I know of four 996 needing new tranny's up here in Toronto... and about 3 others I know who track their car have already replaced/repaired their transmission... and they are not on the forums... and yes the M9X engine program is a joke.... blown engines are probably more common than 996 tranny issues...

[phillipj]

What is the M9X engine program?

[Benjamin Choi]

The car is at a respected local independent as of this morning, awaiting diagnosis. The independent said, as Loren did, that parts are now available from Porsche for transmission repair.

Apparently some specialists have been repairing 996 transmission for years before Porsche made parts available by going to the suppliers used by Porsche.

Shopping around it seems a good rebuilt transmission can be bought for about $3000 w/core exchange. A huge hit, to be sure. :( But about 1/2 of a new motor, fwiw. Let's hope it doesn't come to that. If it does come to that, from what I've seen the US rebuilders of 996 transmissions make some nice upgrades for 1/2 the price of a Porsche-supplied replacement. But like I said. . . let's hope it doesn't come to that!

Searching the web it seems like 996 transmission issues are rare and the ones that crop up usually relate to 2d gear. I was hoping my post would shake out some experiences with transmission bearings, thrust washers, main shaft, etc. But for the sake of all of us, maybe its better that the information isn't out there!

996 transmission issues are not rare... especially @ 60K miles and beyond... pinion bearings.. whiring/whining; gears popping out and crunchy shifts... lots of cars suffer from these symptoms... I believe 996 use brass synchros and there are a lot of shops out there who replace tranny fluid with synthetic thinking it is a superior fluid... fact of the matter is that brass and synthetic don't mix... you cause damage... there is a great video I found that illustrates the failures of 996 transmissions and what typically fails... the synchros are just one part... there are spider gears that fail and of course the bearings....

If 996 tranny issues are not rare and I rarely hear about them posted on 911 forums, then given the frequency of engine failures we ALL read online, the whole M9X engine program has got to be an absolute engineering joke!

You need to listen more carefully then cause this year I know of four 996 needing new tranny's up here in Toronto... and about 3 others I know who track their car have already replaced/repaired their transmission... and they are not on the forums... and yes the M9X engine program is a joke.... blown engines are probably more common than 996 tranny issues...

sorry, though i love reading up on forums, my life beyond the vicinity of a comp and internet connection isn't porsches.

from my reading, tranny issues are more common with the 996TT (diff tranny), much less so in the carreras.

as to the M9X engine program being a joke, you said it.

[c70Pete]

sorry, though i love reading up on forums, my life beyond the vicinity of a comp and internet connection isn't porsches.

really? is that why you've been kicked off every internet forum?

from my reading, tranny issues are more common with the 996TT (diff tranny), much less so in the carreras.

as to the M9X engine program being a joke, you said it.

this is the 996 forum... do you see people taking about turbo's anywhere? B)

[phillipj]

1

[Benjamin Choi]

sorry, though i love reading up on forums, my life beyond the vicinity of a comp and internet connection isn't porsches.

really? is that why you've been kicked off every internet forum?

from my reading, tranny issues are more common with the 996TT (diff tranny), much less so in the carreras.

as to the M9X engine program being a joke, you said it.

this is the 996 forum... do you see people taking about turbo's anywhere? B)

yes, i'm quite the talk of the town and certainly you're talking about me too. ;) the banning was all absolutely under my control. if i didn't want to get banned, i wouldn't have period. holla at yo boy.

and the 996TT transmission note is to provide additional info since we are in a 996 forum. you can find a wealth of threads describing 996TT transmission issues whereas with the carreras, not so much. compare and contrast. 996TT engines considered "bulletproof" and i'd say from my readings the carrera trannys are just as "bulletproof" in comparison to the 996TT transmissions.

to which i'm attempting to curb your boy cry wolf claim that lots of 996 carrera (since you boxed us in) transmissions suffer from various undesireable issues at your magical 60K miles based on 3 or so of your race car hobbyist buds, et al.

let's get a grip here. i'm not a porsche fan boy to chalk up the engine fiasco as nothing ... but to then claim that the 996 carrera transmission is also a weak point in the car is one in the same... WEAK.

the 996 carrera transmissions are solid, reliable units and should NOT get the reputation spread around the interweb that they begin to fail post your unicorn 60K number.

[Benjamin Choi]

Oh yes, Loren, thx for the correction. it's good to know since i'm approaching 60K here and i am expecting some odd noises and mechnical issues per Pete and his track buds in about 300 or so miles.

[c70Pete]

Oh yes, Loren, thx for the correction. it's good to know since i'm approaching 60K here and i am expecting some odd noises and mechnical issues per Pete and his track buds in about 300 or so miles.

yup if your tracking its a whole different ballgame... service intervals become much shorter... and parts just don't last as long... I don't think Porsche ever designed the 996 to be heavily tracked... for that they recommend you go and buy a GT3... and even that has a lifespan...

[Darqangelle]

Any ideas where a guy can BUY a GT3 engine?

(Not to hijack the thread... it's just...you know...while we're here...) ;)

BTW: Pete - clear your inbox, man... it's full. I can't reply to you.

[c70Pete]

Any ideas where a guy can BUY a GT3 engine?

(Not to hijack the thread... it's just...you know...while we're here...) ;)

BTW: Pete - clear your inbox, man... it's full. I can't reply to you.

okay thx...

I think you can try suncoast porsche for a gt3 motor... but I don't know what the conversion costs are... it would be worth it cause those engines are practically bulletproof...

[phillipj]

Yikes ! I can only imagine what Porsche would want for a core charge :cursing: