andrew2008

I changed the transmission fluid today. With only about 12000 miles, there
was still quite a bit of metal debris on the drain plug:

before


after


The recommended interval to change the transmission fluid is 120000 miles/12 years, which seems too long.

The DIY writeup to change the fluid was very helpful. One thing I might add is to remove the plastic
panels under the car a T20 star (torx) driver is needed.

Crazy Canuck

I change my mostly track driven 996 GT3 twice a year. I only drive it about 4000km.

malmasri

This shows that the plug is doing its job...for a track vehicle it is not a bad idea for annual fluid replacement on transmission and gearbox.

TRAKCAR

On tracked GT3's annual is not enough IMHO. I waited a year and 30 track days and it was way too long. I do it every 8-10 track days now.

atr911

If you ask the guys who rebuild them, they'll say it depends mostly on the length of your sessions at the track. The oil in the gearbox will continue to rise indefinitely during track use if you don't have any sort of cooling system on it. The gear oil temp is generally acceptable until you surpass 20 minutes of continuous track driving. The degradation of the fluid and it's ability to protect your diff and gearbox is drastically affected by heat. If you're only seeing 20 minute sessions on the track, you're probably good with oil changes every year (maybe twice if you have an LSD and want to be safe). If you regularly see sessions going over 20 minutes or are racing, most shops will recommend a cooling system ($$$$$) or changing fluid every or every other event.

This is what I learned when I was researching driveline upgrades and maintenance. Heat = bad

mooty

who does track session less than 20min? you might as well not drive.
30 is about good. longer the better.

i did 17 days on one change. i got sludge coming out. so i will try 8 days next.

911SLOW

^When you start measuring oil intervals in days or minutes you know that you are in the dead zone of the slippery slope. Nice.

BTW if you have added shorter R&P better change every 5K regardless of track usage.

Simple rule so one won't forget I change oils every 5k including tranny and everything else every 10k. 2 numbers I can remember.

atr911

Most sessions here are 25 minutes. PCA is about that too.

The point was that at around that time, the fluid starts to get hot enough to start reducing it'd benefit. 30+ mins and you should be using a cooling system.

LSD in a GT3 increases gearbox temps quite a bit too.

mooty

every event brk are bled (i dont need to, but i do it anyways), and pads fliped.
every other event, i change oil
every other oil change, car is re-aligned and tranny oil changed.
every year, all spark plugs changed, all fluid changed.
every other year all coolant related tubings, connections changed.
when in doubt, just change it.

TRAKCAR

every event brk are bled (i dont need to, but i do it anyways), and pads fliped.
every other event, i change oil
every other oil change, car is re-aligned and tranny oil changed.



every year, all spark plugs changed, all fluid changed.
every other year all coolant related tubings, connections changed.
when in doubt, just change it

Sounds like good advice, just added it to my calender through 2020.
My RS will have to last till my 50th birthday, so another 300 or so track days.

gota911

Mooty, have you ever kept a car long enough to do #4 and #5????

malmasri

Are you kidding me, 30 track days/year, that is like 2 years for me

mooty

yep. but usually i sell them right after they are fully serviced. my girls leave fully pampered.

452gt3

Mooty, can you expand a little on the cooling system maint. you do?