Jaxmemo

I recently replaced the transmission fluid and filter at almost 100k miles. The old oil was filthy. Since the fluid change, I started to notice the following issues:

1. hard downshift after a long drive, this happened once. I had to take an exit that required me to slow down quickly. While the car was downshifting, the vehicle jerked really hard through at least 2 gears, I was in sport mode at the time. Since then, I didn’t drive long enough or had to slow down that quick so it hasn’t happened again.
2. if I slow down to where the car is downshifting or if I am coasting around 3rd gear and I hit the gas hard for a fast take off, the tranny jerks for a second or two before it downshifts to take off. This always happens in the scenario described.

The car has a new transfer case. Besides what I listed above, the car drives fines, shifts smooth through gears even I floor it. I have no issues in going from P to R to D and the throttle is response hood. I researched for multiple hours and came across two possible causes and I wanted to get your thoughts on what this could be.

1. low tranny fluid (currently there are zero leaks however I extracted 7 quarts plus whatever dripped out while the pan was open for a week. I am thinking tranny needed more than 7 quarts)
2. the valve body might be in its way out (the car was shifting fine before the fluid change)
3. reset adaptations
4. filter installed incorrectly

Additional background: The filter brand was hengst from FCP Euro. Oil was 7 quarts Febi 29934 (oem oil with out Porsche price tag). The oil drain was done by me however 4 bolts broke while taking off the tranny oil pan. After a full week of no luck removing the broken bolts, I got the vehicle towed to a local Indy that works on German cars. I installed the new filter and the oil pan so that the tranny wasn’t exposed while being towed. While installing the new tranny filter, I replaced the old o-ring with the new, I recall hearing and feeling the filter sliding in to the new o-ring and not move after it popped in so I don’t believe the issue is the filter. The Indy extracted the broken bolts and added the new fluid back in. The mechanic said he used all 7 quarts of oil, there was tinny bit oil left in his oil filler tank.

Thank you all in advance and apologies for the long message.

luciano136

I just had mine changed as well. To get all the fluid out, my mechanic dropped the pan and filled it with 9 quarts of OEM Porsche transmission fluid. So, I'm guessing you're low on fluid. '14 GTS by the way. Shifts like a dream but it did before the change as well. On a side note, the fluid was already discolored at 54k mi. '14 GTS btw.

garrett376

The amount put back in isn't what's important; it has to be filled at a certain temp. It seems many people underfill or wait too long for the transmission to heat up to gauge the oil amount.

Jaxmemo

Thanks for the reply! 9 quarts, yikes I am possibly 2 quarts short.

Jaxmemo

I will take a stab at it by filling it myself. I have a scanner that will read the tranny oil temp. Should I start off with pumping in a quart, let the temp reach 40C, remove/unscrew the fill tube, and once it comes to slow drip, plug it back up?

I read a lot online but it gets fuzzy understanding the details around filling it up. Do I intentionally overfill before it reaches 40C and unplug it at 40C to let it drain?

deilenberger

Logically I can't see anything wrong with what you propose.. if you fill it cold to the overflow height then let it heat up to temperature, and cap it when it reaches 40C (and stops dribbling) you should be OK. Of course it's not my car, so I will be interested in how it works out.

garrett376

These cars are way too particular, and expensive, to do this without the manual guiding you. With that said, it's extremely important to follow the instructions about moving through each of the four gear positions for 2 seconds, several times. And if you opened the cooling circuit to do a flush of sorts, you will need to make sure you reach 100ºC to fill that circuit up completely, otherwise your final filling level will be off as well. And finally, if the vehicle is not level, your filling level will be off. Overall, there are far fewer issues and less of a chance of being under filled if you fill at the lowest part of the range, at 35ºC. That means when the AC is off, idling engine, in Park, there is a slight stream dribbling out at 35ºC.

twodollardoug

If I remember correctly, I overfilled mine (on purpose) then brought it up to temperature, then drained to the correct level.

deilenberger

If the system hasn't been drained, and also if the valve body wasn't touched - even if the system has been drained, it's much less critical to go through the going through the gears routine on refilling or topping it off. The oil circuits for the valve body and the hydraulic solenoids that move gears around are designed not to drain. They only drain when the valve body is removed. If the valve body is removed then it is critical to go through the gears to make sure all the hydraulic circuits in the valve body and above it are filled.

The process of filling it when cold, then letting it dribble out until the temperature reaches 35-40C should work just fine IMHO if done as a "topping-off" procedure. One comment - to do this you need the fill-tube stub that screws into the inner hole in the drain plug. It's that or you're going to have to use a rubber cone or other device to make a seal to push oil up into the transmission (it's filled through the drain plug..) If you have the fill tube, that can be screwed in and a hose from your hand transmission oil pump can be connected. Without that part - which is pretty cheap - it will be a difficult job to complete.

Jaxmemo

Super helpful. Thank you all! Also, has anyone else used over 7 quarts of oil during the refill process?

CAVU

OP,

Did you reference AllDataDIY or MItchells DIY? There are two different fluid level check procedures depending on whether or not you also opened and drained the ATF cooler lines. There are also a series of shift positions to select.

Jaxmemo

I didn’t reference those two sites, I don’t have subscription to access them and I didn’t drain the cooler lines. I read the DIY on rennlist, for top off procedure, it requires the car to be in P, basically overfill and once the temperate reaches the magic number, let it drain it until it forms continuous drip and install the plug.

CAVU

I recommend a subscription to either. Price is very reasonable for the value considering it is all Porsche provided instructions and specific to your model. What is your model and year?

as Garrett376 noted also:

For example, without opening the transmission cooler lines, one of the steps after adding the fluid for "ATF cooler lines were not opened ...Press the brake pedal and shift the gear lever slowly through P-R-N-D three times. Hold the selector lever in each position for 2 seconds..."

Another example are steps that are different if the cooler lines were opened: "...The ATF temperature must be 100 °C (cooling system open). .....Let ATF cool down to approx. 35 °C...."

Jaxmemo

It’s 2013 v6 3.6L Base

Jaxmemo

First of, I like to thank everyone for your time and for contributing! With your help, I followed the top off procedure and got my issue resolved:

I turned on the engine, went through P-R-N-D for 2 second in each gear, 3 times. I proceeded to unscrew the drain plug and hardly any fluid came out. I pumped in a quart of new ATF while the engine was running. I disconnected the fill pump from the tranny and left the plug off, small amount of fluid came out in a steady stream before the tranny reached 35C. When the tranny reached 38C, the oil started to drip and I eventually put the plug back on.

I went for a long drive where the car reached its operating temperature. Drove it like I stole it to repeat the conditions that caused the issues outlined in my original post however the car drove great. I experienced smooth upshifts and downshifts.

In conclusion, the tranny was running almost a quart low on ATF.