Tranmission Flush: Can it be done?
 

Hey gang,

I got about 67K miles on the '01 986 and the tranny fluis never had been service. I would like to flush out all of the fluid in there.

1. is there a hose or location of fluid return line?
2. approximately how many qt does the tranny/TC hold?

I have done these flush on other cars (FWD and RWD) w/ and w/o transmission cooler and they all have a return line that dumps the fluid back into the pan.

Manual trans or Tip trans?

You don't need to do a "flush". Just a drop and refill with the manual trans. Not sure about a Tip.

Manual takes about 3 quarts of Porsche OEM 75W90 fluid that can be purchased at Sunset for about $28/quart. You can do an UOA on the old oil at Blackstone and get a report like this:

check the tool you need to get the fill port open - if your car is a five speed you need a 16 mm XZN triple square bit. it would suck to get the fluid drained and then not be able to fill it back up. on that note, you'll also need something to lift the fluid up to the fill port; most use a suction gun.

as stated, the oem fill is the most accepted approach here, but some also use redline 75w90ls. beware, however - transmission fluid generates as much discussion as 'what oil to use' around here.

assuming you have a tip:

the tip wasn't built to be regularly serviced. it's supposed to be "lifetime" fluid. that said, yes it can still be changed. to do so you'd need to drain the current oil, drop the pan, replace the gasket, replace the filter, put pan back on. fill through the same hole it was drained from until it starts to come back out. run the car until the transmission gets to a specific temperature (i believe ~95ºf). fill until the fluid starts to run out. get back in, run through the gears and top off the fluid again.

i'm at 103k miles on the original fluid, fwiw.

For Tip tranny fluid change check out this Wheeler Dealers episode on a Boxster S, or PelicanParts's site;

Wheeler Dealers:
Wheeler Dealers - Porsche Boxster S by carvideoseu - Car Videos on StreetFire

Pelican Parts:
Pelican Technical Article: Changing Boxster Automatic Transmission Fluid - 986 / 987

1. There are no fluid return lines as the water to oil transmission cooler is mounted directly on the side of the transmission; only coolant lines run to it and back to the main system.
2. Refilling the Tip is a treat (there is no dipstick for these transmissions), it is done from the bottom of the transmission pan using a pump or air displacement system to push the fluid up into the gear box. Dumping the pan and changing the filter, you will need about 6 quarts of fluid because a normal service does not drain the converter. We only use Porsche spec'd fluids as these transmissions are sensitive to what kind of fluid is in them. As others have mentioned, you need to bring the car up to temp while up in the air, run the trans through the gears, and let any excess fluid bleed out of the fill port.

Like other "so-called" lifetime fluids, the Tip should be serviced at least every 50-60k miles.

Oops, yes, it's an automatic tranny.

I'll just drain and fill several times in the next oil change. I really don't like the method because I'm switching to a non-porsche brand but compatible and I believe it's best to switch to it completely isntaed of mixing it. I guess it is what it is!

Thanks guys.
Close thread please!