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Clutch or torque converter? Three pedals or two? That’s the question prospective buyers asked themselves around twenty years ago when ordering their new Porsche 996 and the one you need to ask yourself before looking for a 996 on the used market. Porsche offered their first water-cooled Carrera with two transmissions: a six-speed manual or a five-speed automatic they called the Tiptronic. Both options were updates of the units in the 993, providing dealers and buyers with some familiarity with the all-new 911.  

The 996 was a leap of faith; a new chassis with a new engine, suspension, and radically different interior and exterior styling. But Porsche stuck the landing, albeit not without a wobble or two, and the latest model to enter Porsche Classic support is now enjoying somewhat of a renaissance. The styling has aged better than everyone expected, and the performance bargain it has become is beginning to gain some notoriety. So if you’re looking to get into a 996, which transmission suits you? Let’s find out.

Read Our Full Porsche 996 Buyer's Guide

 

 

Porsche 996 Manual Transmission Information/Design/Tech Specs (Getrag G96)

The Getrag units used for the 996 were continuations of the G64 gearboxes used in the last air-cooled 911s. Without sacrificing strength, the 996s gearbox has proven reliable and relatively inexpensive to fix. They’ve also proven reliable up to 500hp in the Carrera chassis and even more when used in others. If you’re after something more suited to the track, the aftermarket is flush with options to accommodate more power and aggressive driving.

 

Getrag G96.00/G96.30 (1999-2001 Carrera & Carrera 4)

The first series of the 996 to leave Stuttgart came equipped with the Getrag G96.00. The six-speed transmission was the standard option in all of the normally-aspirated Carrera models between 1999-2001. Both transmissions use a cable-operated shifter with a hydraulically-operated push-type clutch. A mechanical limited-slip differential was only available in 1999 models with the cable-operated throttle body.

Porsche 996.1 Transmission G96.00

The all-wheel drive Carrera 4 models received the G96.30. It is primarily rear-wheel-drive biased, but the center viscous coupling will lock and send power forward when wheel slip occurs. The minimum torque applied to the front axle is 5%, and it can send as much as 40% of the available torque to the front axle, depending on traction and conditions. 

  • Oil capacity: 2.7L API classification GL5 75/90
  • Clutch System: Hydraulically-assisted push-style pressure plate, 240mm unsprung clutch disc, dual-mass flywheel
  • Gear Ratios:
    • 1st gear 3.818
    • 2nd gear 2.20
    • 3rd gear 1.516
    • 4th gear 1.216
    • 5th gear 1.024
    • 6th gear 0.841
    • Final drive 3.444

 

G96.01/G96.31 (2002-2005 Carrera, Carrera 4, & Carrera 4S)

2002 saw the introduction of the 996.2 with its bigger 3.6L engine and increased power output. However, the manual transmissions stayed virtually the same. The most significant physical difference is in the size of the transmission case; the .01 and .31 boxes grew two inches at the tail. Gearbox mounting stayed the same, but the driveshaft on the C4 models was shortened by two inches to accommodate the longer case. 

Porsche 996.2 Transmission G96.01

The updated box also received some updates inside the case. The early 'boxes use two bearings on the input shaft, whereas the .01 and .31 gearboxes use three to better cope with the strain on the shaft. A new differential with four spider gears replaced the old that used just two for better durability. Porsche changed the pressure plate and release bearing slightly to match the increased engine output on the clutch side. These gearboxes will bolt into the 996.1 chassis without an issue and are easily identified by their bolt-in axle flanges.

  • Oil capacity: 2.7L API classification GL5 75/90
  • Clutch System: Hydraulically-assisted push-style pressure plate, 240mm unsprung clutch disc, dual-mass flywheel
  • Gear Ratios:
    • 1st gear 3.818
    • 2nd gear 2.20
    • 3rd gear 1.516
    • 4th gear 1.216
    • 5th gear 1.024
    • 6th gear 0.841
    • Final drive 3.444

 

G96.50 (2001-2005 Turbo & Turbo S)

While similar in name to the Carrera transmissions, the G96.50 is closely related to the G50 used in the air-cooled 911s of the nineties. Externally, the .50 is roughly the same size and weight as the N/A boxes but uses the bell housing pattern of the Mezger engine case. That makes the .50 incompatible with the 996 Carreras. 

Porsche 996 Turbo Gearbox G96.50

Inside the transmission, the gear sets are splined together rather than press-fit in the Carrera boxes. The splined design makes it very easy to swap out gear sets in the paddock during a race weekend. Although the Turbo is more Grand Tourer than a race car, its gearbox uses the same case and some internal parts as the GT3, GT2, and Porsche’s race cars of that era. Triple cone synchros are used on the first and second gears, while third through sixth are single cones. Third through fifth gear synchros are made from steel, too, for that extra strength. All gears in the Turbo gearbox are cast steel. 

That pedigree and its engineering have shown up through owners pushing 1000whp through these transmissions with the right parts in place. However, Porsche didn’t get it all correct with the clutch system for the Turbos. The engineers over in Stuttgart tried to make the clutch softer and more usable in traffic by making it power-assisted. They used part of the power steering system to reduce the pressure needed to depress the clutch pedal and ended up with a complicated system prone to failure that delivered poor feedback through the pedal. Twenty years after its introduction, multiple companies offer a solution.

  • Oil Capacity: 3.8L API classification GL5 75/90
  • Clutch System: Hydraulically-assisted pull-style pressure plate, 240mm unsprung clutch disc, dual-mass flywheel, power-assisted slave cylinder
  • Gear Ratios:
    • 1st gear 3.82
    • 2nd gear 2.05
    • 3rd gear 1.41
    • 4th gear 1.12
    • 5th gear 0.92
    • 6th gear 0.75
    • Final drive 3.44

 

G96.88 & G96.96 (GT2 & GT3)

The gearboxes used in the GT2 and GT3 are nearly identical to the G96.50 found in the Turbos. They use the same transmission case and gear assembly but with different ratios. The main differences come from the synchros and the cooling. Every other Porsche gearbox from this era uses brass synchros for smooth engagement on the street when the box is cold. The GT2 and GT3 are built for track use, so Porsche used triple-cone synchros on every gear and used steel pieces on second through sixth gear. Their resistance to wear is much greater than the brass synchros, but they are more challenging to shift while the gearbox is cold. Additionally, both transmissions utilize an internal oil pump with an attached oil cooler to keep the transmission temps down on the track.

Porsche 997 GT2 Transmission G96.88

Standard differentials are mechanical limited-slips, though their friction plates don’t have the best reputation for longevity. Many owners switch to Guard or OS Gikken plates inside factory housings. 

 

GT2 (G96.88)

  • Oil Capacity: 3.8L
  • Clutch System: Hydraulically-assisted pull-style pressure plate, 240mm unsprung clutch disc
  • Gear Ratios:
      • 1st gear 3.82
      • 2nd gear 2.05
      • 3rd gear 1.41
      • 4th gear 1.12
      • 5th gear 0.92
      • 6th gear 0.75
      • Final drive 3.44

 

GT3 (G96.90) 1999-2003

  • Oil Capacity: 3.8L
  • Clutch System: Hydraulically-assisted pull-style pressure plate, 240mm unsprung clutch disc
  • Gear Ratios:
      • 1st gear 3.82
      • 2nd gear 2.05
      • 3rd gear 1.56
      • 4th gear 1.21
      • 5th gear 0.97
      • 6th gear 0.82
      • Final drive 3.44

 

GT3 (G96.96) 2004-2005

  • Oil Capacity: 3.8L
  • Clutch System: Hydraulically-assisted pull-style pressure plate, 240mm unsprung clutch disc
  • Gear Ratios:
      • 1st gear 3.82
      • 2nd gear 2.15
      • 3rd gear 1.56
      • 4th gear 1.21
      • 5th gear 1.00
      • 6th gear 0.854
      • Final drive 3.44

 

Porsche 996 Carrera Manual Transmission Problems 

  • Second Gear Pop-Outs
  • Pinion Bearing Failure
  • Worn Shifter Bushings
  • Worn Transmission Mount Bushing
  • Cracked Thrust Washer

The G96.00 and G96.01 boxes are fairly stout pieces, but they aren’t perfect. Porsche did their homework and mostly set everything where it needed to be, but they couldn’t account for cast defects and bad metal. Yet, when something goes wrong inside of them, it’s almost always from user error. 

 

Second Gear Pop-Outs

The most common failures on the G96.00 and .01 gearboxes come in some form of issue with second gear. Depending on what went wrong, the transmission will grind during engagement, put up a fight during engagement, or pop out of gear under trailing throttle. 

Porsche 996 Carrera G96 Gearbox 1st 2nd shift sleeve with damaged engagment teeth 2nd gear side (2)

Worn synchronizer assemblies are the root cause of the grinding noise during engagement. Second gear sees extensive use, and not every owner can shift their transmission as they should. However, clutch adjustment issues can also cause grinding. If the clutch doesn’t disengage completely, there will be an excess strain on the gearing that’ll cause rapid degradation of the synchros. Not every owner is gentle on the synchros, either. Hole shots and quick shifting put excess strain on the internal components leading to this failure.

Porsche 996 Carrera G96 Gearbox worn out 2nd synchros and damaged engagement teeth

The harsh engagement and refusal to stay in gear comes from a worn-out shift sleeve and engagement teeth. Porsche installed many of these G96s with incorrect shimming that causes the shift sleeve’s teeth to clash with those on second gear. As a result, the engagement teeth just wear out over time. Unfortunately, the proper fix to this problem is a replacement sleeve and the correct shim stack, which necessitates a complete gearbox rebuild. However, a few cheap and quick aftermarket solutions will band-aid the issue.

 

Pinion Bearing Failure

This issue is far less common than the problems with second gear but appears frequent enough to be considered a regular issue. The differential’s spider gears and the pinion’s teeth begin to pit and deteriorate, sending metal shavings into the gearbox that load the bearing with debris. That debris gets thrown around in the bearing, destroying the race and creating a whining noise similar to a failed wheel bearing. 

Porsche 996 G96 pitted pinion

The only way to fix the issue is to disassemble the gearbox and replace the bearing. It may be cost-effective to replace the transmission with a used low-mileage example, though you risk having the second box kill its bearing too. Porsche mainly remedied this issue by adding the extra spider gears for better torque dispersion, but there have been unlucky .2 owners who’ve encountered this issue.

Porsche 996 G96 pitted pinion bearing race

 

Worn Shifter Bushings

The G96 gearboxes were a departure from every past 911 gearbox in that they were shifted via cables rather than a linkage. It allowed Porsche to reduce its parts cost and simplify the connection between the shifter and transmission; however, its first crack at the shifter assembly needed improvement. The assembly is nearly all plastic, save for the lever, which commonly wears to the point of vague shifts in the middle gate. 

Porsche remedied the problem with their next car, the 997, and that unit is a direct replacement for the standard 996 pieces. The later OEM unit gives more feel with a slightly shorter throw. Though, there are plenty of aftermarket fixes to this issue if you prefer that route. These range from new shifter bushings to complete shooter assemblies CNC cut from aluminum. 

 

Worn Transmission Mount Bushing

Each G96 uses a nose-mounted bushing pressed into the case to support the transmission. As with any rubber bushing, they can and will wear over time through regular use. A worn bushing can cause shifting issues that look and feel similar to internally-caused problems, so it’s best to ensure that the bushing is in good health before a major service. 

Porsche 996 G96.00 bad trans mount

 

Cracked Thrust Washer

The gear stack naturally has a significant amount of torque flowing through it, and over time, that can have an adverse effect on internal components. Specifically, a thrust washer sandwiched in the gear stack is a relatively common culprit on heavily tracked 996s. Regular abuse will cause the washer to crack and wear on the mainshaft, necessitating a complete disassembly and rebuild. Luckily, street-driven examples hardly ever experience this failure, so many 996s will never experience a failure like this.

Porsche 996 cracked 3rd 6th thrust washer

 

Porsche 996 Turbo & GT Manual Transmission Problems 

  • Oil Pump Wear
  • Synchros/Shift Sleeves/Gears
  • Case Bearings
  • Tensioning Plate
  • Shift Fork Roll Pin
  • Clutch Fork Pivot Shaft Boss

The Turbo and GT gearboxes are a completely different design from the Carrera gearboxes and use a unique internal structure. Their parts and problems are limited to the models they come in and differ from the Carrera's. These problems are also only an issue for heavily tracked and abused transmissions. Street-driven, unmodified cars are largely resigned from breakage.

 

Oil Pump Wear

The GT2 and GT3 gearboxes are unique to all others in the 996 range as they have an internal oiling system to help keep all their moving parts happy and cool on a race track. The main component of that system is the pump, whose responsibility is to pick up and distribute the oil. Through various ways, debris can be released into the oil only to be distributed around the inside transmission. While small bits of debris from worn oil aren’t an enormous deal, metallic bits from rushed synchros and worn bearings are. 

Porsche 996 GT2/GT3 oil pump moderate wear damage

In many cases, the contaminated oil is then picked up and distributed through the oil pump. Unfortunately for owners, that debris can and will wreck the inside of the oil pump and necessitate a replacement. It’s around $2000 for a new pump. Porsche did place a screen on the oil pick-up, but those are ineffective. The best solution is to have the oil filter from a Cup Car (race car) gearbox fitted along with regular oil changes after track days. 

  

Synchros/Shift Sleeves/Gears

An issue on all of the Mezger gearboxes are worn synchros and shift sleeves. Looking around the forums, you’ll find countless threads on second gear problems, and in just about every case, it is user generated error. Lack of rev matching or poor efforts combined with the hard shifting conditions of a drag strip, autocross, or track day will wreak havoc on them.

First to go are the engagement teeth before stresses get to the shift sleeve and then eventually the gear itself. While most common on second gear, it isn’t out of the ordinary to see them on third and first as well. The synchros in the GT and Turbo boxes use steel synchros on gears 3-5, so they’ll tend to take the abuse better. Replacing 2nd gear with new synchros and a 1-2 shift sleeve is another repair that is nearly $2000 in parts. 

In modified applications, the gears themselves can also break. All street Mezger gearboxes run cast gears from the factory, and although they can take a good amount of power, they aren’t indestructible. It isn’t always the power that gets to them, though. Wide and sticky tires can put additional stress on the transmission housing, which is then transferred internally to the output shaft and the gears themselves. A forged Porsche Motorsport Cup Car or aftermarket gearset are the standard replacements for weaker factory pieces.

 

Case Bearings

While stress from stickier tires can assist with breaking gears, owners will generally see those forces affecting output and input shaft bearings. Again, this is an issue on neglected and heavily tracked transaxles. The stresses put through the case, especially the pinion shaft, can tax the bearings to the point that they will degrade fairly significantly if not serviced properly. 

Porsche 996 Turbo Gearbox case bearing

The worn bearings will create a whirring or almost gravel-like noise while the clutch is engaged. On top of the importance of having healthy bearings, you need to watch out for the debris they cause when they wear beyond acceptable levels. In most cases, the rollers force themselves against the races, pitting the race surface into something that mirrors the moon's surface. The metallic debris sent through the gearbox will then damage the rest of the bearings and the internal oil pump (GT only).

 

Tensioning Plate

The tensioning plate, also called the bearing retainer plate, holds the mainshaft and pinion shaft bearings inside the gearbox. Under normal driving conditions, the bearing plate is already a wear item, but more horsepower and extensive track time do increase the wear rate. If left for too long, the bearing race and its shims will spin inside the plate and gouge the plate. If there’s an upside to this issue, it’s that it’s uncommon to happen before other bearing issues and should only require replacement with other gearbox servicing. 

Porsche 996 Turbo G96 Gearbox spun bearing and shim in tensioning plate (2)_LI

 

Shift Fork Roll Pin

The first and second gear shift fork is secured to its rail via two roll pins. It isn’t unusual for the pins to begin to walk in the bores and back themselves out after abuse. The pins aren’t small and will get caught in the gears if they back out. The fix here is a new fork and some safety wire through the roll pins, just like Porsche used in their Cup Car gearboxes. 

Porsche 996 GT3 GT2 G96 Gearbox 1st 2nd fork roll pin about to walk out

 

Clutch Fork Pivot Shaft Boss

The clutch fork rides on a shaft that sits in two bosses cast into the transmission case. Cast aluminum is strong, but heavier clutches and hard use will wear them down. Cracked bosses will affect clutch operation and can put lateral loading on the throw-out bearing, which will cause abnormal guide tube wear. 

 

There are a few fixes here with varying levels of intensity. The “easiest” repair is to grind and weld the cracked bosses. However, cracks can form along the welds or on other places of the boss, so it isn’t a guaranteed lifetime fix. The other way is to lop the outer half of the boss off, drill and tap some bolt holes, and use an aftermarket cap to form the boss from a stronger material. 

 

Porsche 996 Manual Transmission Service Intervals

Porsche put a lot of time and effort into ensuring the life of the transmission. Following their service intervals and oil recommendations will give you the best chance at a long service life and a great feel. Porsche recommends a fluid change every 90K miles with 2.7 liters of OEM Porsche transmission fluid. Carrera 4 and 4Ss should also replace their front differential fluid with the required gear oil at the same interval.  

 

Porsche 996 Carrera Manual Transmission Modifications/Upgrades

Short Shifters

The most common upgrade to the drivetrain is some sort of short shifter or shift upgrade kit. The OEM assemblies become vague after the plastic bushings wear, making shifting less than enjoyable. There are plenty of options for upgrading here, from the 997 Carrera shifter to the 997 GT3RS shifter, to Numeric Racing’s CNC aluminum shift assembly. You can also keep your stock housing and replace the internals with the EVOMS billet short shift kit or the Ben Auto Design piece. 

However, it isn’t all roses and rainbows when using an aftermarket short-shift kit. Porsche designed their shifter assembly with synchro tolerances in mind. Aftermarket pieces inherently shorten the time the synchros have to engage the next gear, putting extra strain on the synchros. The OEM GT3RS assembly isn’t a fix as its transmission uses different synchros. You’ll be hard-pressed to find owners who share the same thoughts, so install at your own risk.

 

Shifter Bushings

Fixing the sloppy shift feel doesn’t have to come from a new shift assembly. Phenix Engineering and Function First offer solutions that work with the factory shifter assembly for those who like a DIY project. Although they aren’t exactly the same, both kits replace the original plastic bushings with machined aluminum pieces. 

 

Second Gear Pop-Out Prevention

Other than not abusing the gearbox, there are several aftermarket fixes to prevent second gear issues. GBox out of Colorado has designed a modified detent to prevent any pop-outs. The detent is machined to compensate for the factory’s shimming issues, moving the shift sleeve into the proper position against second gear. It’s a relatively simple installation process that doesn’t require removing the transmission. Relatively cheap, too; it’s a simple fix for a transmission that hasn’t had its shims addressed. 

CMS 996 shift arrester and detent spring spacer

Another company, California Motorsports, has developed a modified shift arrestor to prevent the pop-out issue. The arrester is mounted inside the transmission, behind the tail housing. Once installed, it allows “second gear to engage all the way, every time.” This is insurance against a future issue rather than a fix.

 

Shift Cables

Shift cables are your next best solution to vague shifting after any modifications to the shifter. Directly linking the transmission to the shifter, the stock cables use plastic components that can wear and introduce slop. Additionally, some aftermarket shifters require updated or aftermarket shift cables, so know what you need before buying. The non-OE pieces will offer metal components in place of the original plastic bits and thicker cables for a better feel. However, their effectiveness is subjective. Browse through some forums, and you’ll find plenty of threads debating their effect. 

 

Clutch/flywheel

The 996 and subsequent models use a dual mass flywheel from the factory. You can relapse the heavy dual-mass flywheel with a lightweight single-mass unit to quicken the engine's response time and shift duration. The single-mass flywheel is cheaper to buy, doesn’t have any moving parts to go wrong, and has less mass for the engine to spin. However, Porsche engineered their cars with the dual-mass unit in mind. Their construction lets them absorb harsh driveline vibrations, reduces the strain on the driveline, and makes the 996 easier to drive in traffic. Simply put, your 911 will drive nicer on the street with the OE-spec flywheel.

However, track toys and competition cars will benefit from a single-mass flywheel. The benefits of the simpler unit are track oriented and shine the brightest when in a car that doesn’t often see street driving. Be aware that using a single-mass flywheel will increase the rate at which the transmission’s internals wear down. 

 

Limited-Slip Differential

Porsche offered LSDs as an option for the first year only on the 996 Carreras and all five years for the Turbo. However, both options are very uncommon, so aftermarket options are the easiest way to cure an open differential. Several aftermarket companies offer differentials for the Carrera and the Turbo transmission in true clutch-type LSD and torque biasing form. Wavetrack and Guard Transmissions are going to be your best bet for aftermarket solutions, but others have had success with Quaife and OS Giken.

guard transmission LSD (2)

 

 

Porsche 996 Turbo & GT Manual Transmission Modifications/Upgrades

The gearboxes used on the Mezger engines are of a completely different design than those used in the Carreras. Because of that, their internal components are completely bespoke to their transmission family. The upgrade path for the Turbo and GT transmissions is far greater than the Carrera boxes and they can be built to handle well over 1000 horsepower with the right parts.

 

Gear Sets

The 996 Turbo’s OE gearset is tough but has its limits. 800ft-lbs of torque at the wheels is enormous in a vacuum, but it’s nothing extraordinary for a 911 Turbo. 996 owners can get there with the right engine bolt-ons, so there have been plenty of gearboxes over the years well beyond that. But around that figure is where longevity becomes a concern. A lower power figure mixed with the extreme conditions on heavily tracked cars can also cause a 2nd gear breakage after extensive mileage.

Porsche 996 Turbo G96.50 Gearbox 3rd gear debris (2)

However, more robust aftermarket gear sets are available because of the Turbo’s immense popularity. The OE GT2 mainshaft and 1st-2nd gearset are tougher and taller than the Turbo’s and have shown their strength as the most budget of the options. Sticking with factory Porsche parts leaves owners with components from the GT3 cup car gearboxes. Proven to last over 24 hours at Le Mans and Daytona, they’re tough and will handle as much as anything else while providing a taller choice of ratios to play with.

cup 5th forged version (2) 
Guard Transmission offers the most widely used aftermarket gear set for the 996 GT and Turbo boxes. Their quality and design, which uses modern F1 tooth profiles, make them second to none, especially considering they’re the only aftermarket company to have had their products bought by Porsche Motorsport in Weissach. Buying the full Guard catalog means also receiving their billet mainshaft set that provides a 30% higher torque rating than factory components.

 

Synchros

The OE brass synchros in all Turbo gearboxes are excellent at stock power levels but can get a little soft when the boost is turned up. Regular track time doesn't bode well for the stock brass synchros in the Turbo gearbox either, as they can wear after a few seasons of use. The easy and only real upgrade here is to fit the steel synchros from the GT2 and GT3. They aren't cheap by any means at about $4000 for a complete set, but their strength is necessary at a certain point. Their durability far exceeds the brass components, as proven by Porsche fitting them to the GT cars, so you won't have to worry when you're out banging gears. This is a great "while you're in there" job when upgrading the mainshaft and gear set.

 

Limited Slip Differential

The OE Porsche LSD isn’t the best piece of kit. In almost every 996 and 997 application, replacing the factory LSD with an aftermarket or Porsche Motorsports version provides much better overall performance. I won’t attempt to explain why the aftermarket and motorsports products are better because I’m not certain where the advantages come from. However, I trust the hundreds of owners who’ve switched and provided their first-person accounts of traction and braking stability improvements over the years. 

Porsche 997 GT3 LSD stock friction discs

Regardless of where you get your LSD, you’ll need to decide whether it will be a true limited-slip or a torque-biasing differential. The latter is a perfect street car choice as the lack of friction plates makes them free of servicing requirements, chatter, and binding. Hardly referred to as torque-biasing differentials (TBD), both Wavetrac and Quaife are manufacturers, and their names have become synonymous with that differential style. 

Porsche 996 GT3 Guard LSD friction discs (2)

Guard and Porsche Motorsports are going to be the best option for a plate-type limited-slip as they’re tried and true. Where the TBD can struggle at extreme power levels, the traditional LSD has no such issue. Aftermarket Guard units are made from billet and come with 4, 6, or 8 plates, depending on the power-handling capabilities. Factory Motorsport LSDs are just as tough, but many convert the plates over to Guard pieces come rebuild time. 

 

Porsche 996 Tiptronic Transmission Information/Design/Tech Specs

Porsche introduced a new version of the Tiptronic for the 996 based on the previous unit used in the 993. The new automatic, the A96.00, was built by ZF and featured five forward gears with a “smart” transmission control unit. That smart TCU learned from how the car was driven and calculated its shift points and speed based on the driver’s characteristics. 

Porsche 996 Carrera 4S Gearbox A96.35 Tiptronic S

The introduction of the 996 Turbo saw Porsche switch to the Mercedes-Benz 722.6 automatic transmission. Still called the Tiptronic, the 722.6 was then fitted to the rest of the 996 lineup starting in 2002. Porsche made the switch as its new 996.2 models featured bigger engines with more torque than the ZF boxes couldn’t handle reliably. 

 

Common Porsche 996 Tiptronic Transmission Problems

There truly isn’t much for this section. The ZF and Mercedes Tiptronics are as reliable as they get without any nagging issues plaguing their owners. They are still automatic gearboxes, so you’ll experience slipping and hesitations when they go wrong. The early Tiptronic-equipped cars had a technical service bulletin a few years into their service life for a TCU update, but every 996 using that gearbox today will almost certainly have had that taken care of. 

 

Porsche 996 Tiptronic Transmission Service Intervals

Porsche put a lot of time and effort into ensuring the life of the transmission. Following their service intervals and oil recommendations will give you the best chance at a long service life and a great feel. Porsche recommends a fluid change every 90K miles with OEM Porsche ATF. Carrera 4 and 4Ss should also replace their front differential fluid with the requisite gear oil at the same interval.  

 

Porsche 996 Tiptronic Transmission Modifications/Upgrades

The early ZF-made transmissions are what they are. No upgrades or modifications are available for them. The Mercedes-built transmissions, however, do have aftermarket support and can be made to withstand considerable power. Depending on how much torque you need it to handle and its use, there are a few different upgrade paths for the later Tips.

 

Torque Converter

Upgraded torque converters for the Mercedes 722.6 are available through several companies. However, very few list the 996 as compatible, so the most available option is the unit provided by Evolution Motorsports. It features new vanes inside the converter for a higher stall speed and the ability to hold 800hp reliably. That power level isn’t crazy for the 996, but more than that will require more from the transmission.

 

Software Flash

Quicker cars need quicker shifts; that’s how it goes. EvoMS can help there, too, with their software flash for the transmission control unit. Porsche’s TCU controls the shift points, shift speed, and torque limit at certain RPMs. EVO’s software raises those shift limits, increases the available Torque, and quickens the shifts to take advantage of the extra power. Other companies offer TCU flashes for the 997; however, EVOMS is all there is for the 996.

 

Porsche 996 Transmission FAQ

  • Is the Porsche Tiptronic transmission reliable?

Generally, yes. As mentioned above, the 996.1 and 996.2 Tiptronics are different transmissions, and that’s because the updated box has been more reliable. However, both Tips suffer from the same issues every automatic transmission has. They’ll slip and hesitate when they start to go wrong. The best solution to that problem is a freshly rebuilt gearbox. Later, cars with the MB Tip can have a Mercedes independent shop check it over because of their familiarity with the 722.6. The best cars will have had their regular maintenance performed on time. Many owners have Carreras with well over 100K miles on their Tiptronics. 

 

  • Should I buy a Porsche 996 in manual or Tiptronic?

The transmission you choose depends on what you plan to do with the car. Anything more than street driving is best suited to a 996 with a manual transmission. They’re lighter, simpler, more reliable, stronger, easier to find, and easier to work on than the Tiptronics. The aftermarket is filled with limited-slip differentials, different gear sets, ring and pinion ratios, and shift components to make the G96 as competent on the track as it is on the street.

You should choose a Tiptronic if you’re using your 996 as a Sunday cruiser or a daily commuter in heavy traffic. Not everyone can stand operating three pedals while dealing with constant traffic. Porsche 996 is a great sporty daily driver, and the Tip allows the driver to stay fresh behind the wheel in everyday situations.  

 

  • Is the Porsche Tiptronic good for the street/track?

Street, yes. Track, no. The Mercedes-built Tiptronics can become suitable drag racing gearboxes, but the manual is still best for the track. The manuals can handle regular abuse, provide great feedback, and are the best option for eeking out every last tenth of a second for your personal best lap.

 

While that all sounds like a lot, and it definitely is, it's just about everything you'd ever need to want or know about the Porsche 996's transmissions. A huge thank you to Roger over at Califonia Motorsports for the overwhelming amount of images that helped bring the guide to life and the wealth of knowledge provided for almost every section. If there's anything you can't find here or believe needs to be added, let us know in the comments below! As always, keep your eyes on the DIY Blog for new exciting articles and subscribe to our YouTube channel for regular DIYs and cool builds.

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Written by :
Christian Schaefer

Owner of a flat-six swapped 1998 Impreza 2.5RS and a 1973 Porsche 914. Horizontally opposed views, only.


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