Porsche 944 S - Changing transmission fluid

Yesterday I changed the transmission fluid on the Porsche 944 which was a bit of a giggle of a job. It’s not a difficult job as you can see if you read the how to over at the awesome Clark’s garage. I put Castrol TAF-X transmission fluid in after doing a fair amount of research and got it delivered from Opie Oils. Getting the plugs out (making sure I could undo the fill plug first of course) was OK – needed a bit of power but nothing too bad. First mistake was when I was removing the drain plug and had the bucket ready but then when I thought I had one more turn it popped out and so I missed what was probably a couple of hundred mm of fluid that went on the floor! Not to worry, lots of kitchen paper later and it was mostly clear.

Unlike others, my fluid didn’t smell awful and wasn’t a terrible colour which makes me think that it has been replaced previously and so I didn’t have as much hope for a good increase in slickness and less whine. Once all the fluid was draining out it was time to refill. This, was a giggle. The transmission takes 2.7 litres of fluid to fill and fortunately I had 3. I say fortunately because I lost a far amount of fluid trying to find the best way to fill her up. Access to the fill plug is not easy.

My first try was using some hose into the fill plug and then pouring the fluid into the hose. That proved to be shockingly slow as I could only get hold of some 8mm wide hose. So I had read previously that if your bottle has a long neck you can invert it and slot it in to the fill plug. I tried this and all was going well until I moved my finger off the bottle neck and tried to simultaneously push it into the fill plug. I lose a far bit of fluid there, so that method could not be used for the next two bottles.

So the next bottle I shaved off the top of the bottle neck and shoved it into the 8mm hose. It didn’t really fit but it did enable me to squeeze the fluid through the hose into the transmission. If I squeezed too hard though the fluid would also come backwards out of the join as the bottle neck was too big for hose. Didn’t lose much fluid though. Lastly I used a funnel gaffered to the hose (as the join wasn’t tight). Which wasn’t too slow but the hose could still of done with being bigger. Finally though, with only 200ml of fluid left in my last bottle, the transmission started over flowing meaning it was full – which is good.

So job done – took 2 hours, should be much faster if I ever do it again and the more preparation you put into the filling technique the better. Also I think removing the rear wheel (passenger side) would have been very beneficial.