joe Matta

I recently purchased a 2002 996 C2 with tip trans, first year mercedes transmission.

The car has 50K Mi on it and has had all the services compleated, Trans fluid was checked. condition perfect

Two weeks laiter i took the Car out on one DE event at willow springs and burned up the transmission. It also aparently burned up the TCU unit as well.

The TCU unit is relaced and I am in the process of having the trans rebuilt and put back in the car.

First it is very hard to find a Porsch technition that knows any thing about these transmissions.

I did find a good Porsche , BMW , Mercedes service shop. They pulled the trans and rebuilt it, they also said the transmissionis a stock E class trans. Not a high performance Tiptronic.

I'm very confused and concerned. 1, The tip trans was used in the 2001 turbo and the 2002 3.6 engine should have this same tip trans.
2, can i ever use this trans at the track again?

They did send the trans to an experienced Mercedes shop for the rebuild. the feed back was that the 2nd and 3rd gear drums were broken, input shaft broken, friction plates shot. Cause of failure excessive heat.

The did include a new HD input shaft, 3 extra friction plates, and additional "Pistons" (not sure what they mean by this) possibly valve body or solonoid upgrades?. This was done to improve the trrackabilty of the trans/car

Does someone know if this car would actually have had the turbo tip trans or an E class trans as reported?

Do these modification make any sense, i will be speaking to them again to clarify these modifications.

Does the car have a trans fluid cooler stock and Can I add a additional trans fluid cooler to the car, will this help?

Would it be possible to find a laiter tip trans that would be the so call " high performance" tip trans. that could be used in this car with the TCU and PSM?

I can be reached at joe@hansonlab.com If some one has comments please email me and perhaps we can arrange a phone call to discuss, thank you ,joe

berni29

Hi There

The Tips do have a cooler as standard. You need to check that the fan is working though because the resistors are often kaput. The fan should still run on the high setting though even if it is. Check the relay and fuse. The cooler is sandwiched in with the oil cooler. Check for leaves etc.

Also it is not a simple process to get the fluid level right. Only let someone who knows what he is doing attempt it. The box is a Merc box on my 1994 car. Mine has done 185k miles and seems fine.

Best of luck

Berni

joe Matta

I'm answering my own questions here as I have more information on on the rebuild option on these early tiptronic transmissions. Hopefully this may be of some use to someone in the future.

Aparently these transmissions can carry 3 additional friction plates for a total of 8. The presumption is that the additional friction plates will prevent slippage and wear and heat build up under more extreme loads.

The pistons that were replaced are shorter, ie correct size, due to the additional room required by the extra 3 friction plates. Presumably these are the Pistons that apply pressure to the friction plates in the trans underload.

The tiptronic transmission does have its own external transmission oil cooler. It is an external oil cooler similar to the ones installed on the engine, the cooler is air cooled only, ie not tied into the water cooling system, and an aditional or larger cooler is not possible to add on to this transmission.

FYI, ther are pleanty of aftermarket transmision fluid temperature sensors aviable i will be looking into one before using this car on the track again. Search " transmision fluid temperature sensors " on the internet for more information.

roadsession

Joe...see this...

http://www.trackpedia.com/wiki/Drivi..._at_track_days

joe Matta

Roadsession, i will , thanks, joe

roadsession

2002 to 2005 Carrera 4 and 4S models have the A96/35 Tiptronic S transmission (The 722.6 manufactured by Mercedes for Porsche). The 2001 to 2005 Turbo Tiptronic models had the A96/50 transmission, which is the same on paper except the final drive ratio is 2.89:1.

All Mercedes V12-powered cars such as the S600 and S65 AMG use the 722.6, which has a torque capacity of 796 lb-ft

joe Matta

Roadsession, thank you, any idea what tiptronic was used on the 02 C2? that is what i have, sorry for not clarifying. This would be one of the earliest Mercedes tips put on this car.
Any ideas on a good fit for an tramsmission fluid temperature sensor. I would like to find one that i could install into to the drain plug and run to a guage in the car. thanks, j

Torontoworker

You need to find out what is the operating temperature range for this particular model transmission is and what the 'do not exceed' temperature is. I would imagine that the temperature varies depending on load conditions so you should have an operating 'range' and min/max temp numbers that should be published in a service manual somewhere.

There should already be a sensor on your unit as the TCU needs this as part of the control process. Every automatic transmission I am aware of has a TFT sensor - it's main use is to monitor temp's of the ATF fluid as the viscosity of the ATF fluid changes as the fluid temperature rises and falls. The TCU can then alter the % that the torque converter lock's up the clutches.

FYI: The highest temperatures in your transmission can be found at the output side of the torque converter.

If you could find the senor wiring that goes to the TCU you could in *theory* hook up a display with some form of display/warning device. There are many types of fluid temp warning units on the market.

As far as what type of unit your 02 has; I do know that the ZF (which I have) was introduced for the 996 C2 in the Y98 (Euro) Y99 (US) and was used until the mk2 was produced. If you have access to Durametric's it will read the Tran's type/model and serial number.