Replacing the Ground on a 951
 

Is a royal PITA!

I haven't even gotten a socket on the bolt yet...though I did manage to drop a socket in what I think is the check hole for the clutch. Two trips to Autozone later for telescoping magnets, and I decided to call it a night.

I just re-replaced the ground lugs on my car ONLY beacause I had the intake manifold and oil separator off while performing what I call the "top-of-engine-service". Even with all that crap out of the way it is still a female dog.

While I was in there, I added a big jumper from the bell housing to the back of the cylinder head. There is a convenient threaded 6mm hole on the back of the head next to what feels like an expansion plug for this mod. Why? The coil discharges to ground through the spark plug - right? I now measure zero ohms from the negative battery POST to the head. I forgot to take a reading before I did this, but I will disconnect it this weekend and report my findings. I'm sure it will be more than zero.

I ended up buying a 13mm swivel socket. It made the job much easier (though not easy).

The main ground (13mm) or the #7 one down by the air-oil separator?

I personally find the latter to be a lot worse - it's perfectly situated to drop the bolt into the top "OT mark" window on the bell housing if you're not careful - on top of being a pain to get at.

Clean grounds make 944s happy. Best of luck to you.

And yes, a 13mm socket with built-in wobble is a tool that should be in every 944 owners' toolbox.