Kinesis 996

The gear box been acting funny lately. I recently changed the ATF oil already, but this seems to be an tranny ecu issue.

When move the lever to M mode, during lower rpm, the car will upshift from 1st to 2nd without my command. Same with 2nd to 3rd. I know the car default gear starts at 2nd, but when I select 1st to start, it will act on its own.

Anyone here experienced similar problems?

Macster

Was the Tip acting up before the fluid change?

Did you follow the proper procedure when changing the ATF?

Did you use Porsche ATF?

Kinesis 996

recently changed ATF and is aftermarket. Just forgot the brand off of my head, shop said is as good as the factory one.

Tip didn't act funny before, only happen few days ago. Does it make a difference?

Carlo_Carrera

Yes, the type of fluid makes a difference. You ned to use a type marked ATF134. There are a few different brands that are approved. The OEM brand is Shell. You also need to double check the trans was refilled to the proper level. It sounds like it wasn't or the wrong ATF was used.

Did the shop do the fluid change?

Did they also change the filter?

geetee

car needs tranny fluid filled to level with car hooked up to durametric as tranny fluid needs to be at a specific temp. very crucial

Macster

To add what others have said almost certainly the proper fluid should be used. I do not know what are the possible effects from using a different fluid nor the possible effects from two possible dissimilar fluids being combined.

Given the expense of dealing with a Tip rendered bad by something about the "wrong" fluid being used I have no desire to experiment were I to own a Tip equipped car.

Also, the replacement fluid wants to be added to the Tip via a hose connected to the charging port until excess fluid comes from the bore of the control screw. Then the Porsche diagnostics computer is used to check the ATF fluid temperature and if it is under 40C the engine is started and with the brakes applied the Tip gear shift lever is moved from P to D to R and other positions with the lever being left in each position for at least 10 seconds. Additional fluid should be added just in case the fluid level has dropped.

After this then the Tip chargng port cap with a new sealing ring fitted and properly tightened and the control screw also with a new sealing ring is installed and properly tightened.

clsund1

Wow, didn't realize changing the ATF was so involved. Good to know.

cdk4219

Well since it's either a ZF or a Mercedes 722.6 transmission, the fluid level may be in question. If it is a 2003 up, then it is a 722.6 which can utilize valvoline max life atf, Mercedes atf, Sprinter van att and many more. It is highly unlikely that the incorrect fluid has caused this problem in a short time. While switching to correct fluid would certainly be the least expensive attempt to remedy the situation, the fluid level is certainly the first thing to check. Which transmission do you have?

Carlo_Carrera

The 2003 transmission switch over you are referring too occurred in normally aspirated cars only.

The 996 Turbo used the same Tip gear box in all model years from 2000-2005. The Turbo Tip trans is made by ZF. It is know as a NAG1. The same trans is used in Mercedes MLs, Jeep Grand Cherokees, Mercedes McLaren SLRs and a few other vehicles. The NAG1 trans requires fluid marked ATF134.

You correct about the Vavoline Maxlife fluid. It does meet the specs for a NAG1. You are also correct that the fluid level is most likely causing the OP's issues.

Kinesis 996

Thx for the advice guys. The car when in D drives normal, shift fine, no drama.

Its when in M mode, that it will upshift on its own even in the lower rpm. I am thinking, is the steering shifter wire getting old thats causing this problem? Is VERY annoying.

cdk4219

Definately a Mercedes built transmission. and you may want to disconnect the battery and reset the adaptive part of the TCU. If it is close to the Mercedes software, it may be worth a shot.

Carlo_Carrera

Yes, you are correct. It is a Mercedes not a ZF.

And doing a battery disconnect reset is a very good idea.