944 Foot To The Floor
This is not really a why, but more of a must in my situation. Having had my 944 for little more than six months I began to notice a small fuel leak under the rear of the car. And after a bit of reading on the web it seems early 944's are suseptable to this due to the metal fuel tank they use, which either corrodes or develops cracks due to the flexing caused by the fuel vacuum. So to get to the fuel tank the transmission has to come off. This got me thinking about what else I could do to the transmission if I was going to have to go to all this trouble. So, I decided to change the shifter mechanism, swap out the transmission oil, change the transmission mounts, re-grease the CV joints on the axles and underseal the body work. If you're gonna do a job do it properly. It may sound daunting but the removal of the transmission is relatively simple.
Removing the transmission took me about 6-8 hours being a first timer at this task. A second pair of hands to help with lowering the transmission. There's the Porsche mechanics way of doing it and then there's my way. I used that alongside the Porsche Haynes manual which is just about OK but a bit light on details. Jack the rear of the car up and support it on axle stands at their highest setting. Remove the gear knob and leather shroud by prising up the edge where it meets the centre console with a flat bladed screwdriver. Underneath you'll find a rubber shroud which removes in exactly the same way; exposing a black block with a sprung clip. Before the gear knob will come off completely you'll need to release the clip on the black block with the screwdriver. This will expose the mechanism where the gear stick meets the shifter rod.
Now get under the car and locate the shifter mechanism (located on the top of the transmission between the two rubber transmission mounts). There should be a rubber boot to slide towards the rear of the car that exposes the nut that connects the shifter rod to the shifter linkage. There will probably be a piece of wire threaded through the nut which you will need to untwine before releasing the nut with a 13mm socket. You can now separate the linkage from the shifter rod with a bit of wiggling and pushing it towards the front of the car. Now get back inside the car and remove the circlip that is used to secure the shifter rod to the gear stick with a pair of long nosed pliers and unhook the rod from the stick. You should now twist the gear stick 90 degrees and lay it over as far towards the passenger seat as possible (See photo below). The next stage involves removing the two plastic covers on the bottom of the transmission bell housing (shown below), just prise them out with a screwdriver.
This exposes the 'coupling' between the transmission and the trans-axle that runs the length of the car. There's an allen bolt at either end of the coupling (one per hole). Before you remove the bolts mark a line across the width of the splined (toothed) part of the axle at the transmission end of the coupling with a permanent pen. This will help you slide the coupling back into the same spot when you come to reassemble as you'll notice that the bolts in the coupling actually slide through indentations machine in the axle itself. These indentations are there to prevent the coupling sliding up and down the axle and to make sure the coupling sits equally between the trans axle and the axle going into the transmission. Now to undo the allen bolts (with a long 8mm allen key or wrench) you will need to rotate the trans-axle by hand so you can get to them squarely. To do this you'll want to wedge something onto the clutch pedal (See photo below).