Dunasso

Yea Green mine is consistantly wanting her own. Actually, she wants this one. I've tried giving her the 78 SC but she says it smells like wet carpet inside. Besides the engine went south, so I'm in the process of rebuilding the SCs engine after a unfotunate event at which point I am contemplating a 996 or a Boxter for her. I'll be trading in the SC or selling it outright. It was a purchase that I wish I hadn't made and I've held on to it for too long.

Adrian

This is the main gear assembly which is part of the centre differential lock engage mechanism. It is a Planetary gear set up. A centre gear with three surrounding sun gears.
When the diff lock is engaged all these gears are pushed together. If one is out of alignment for any reason (there are many) the gears which are spinning, will quickly will self destruct.
Out of the 10s of thousands of C4s built I know of around 10 cases of the planetary and sun gear assembly coming apart.
It is not a car design issue it is a people problem. Most people have no idea of the mechanics behind such systems they just jump in and go for it. Dump the clutch at 6000 rpm in front of their friends saying "Look at me". Going bang is going to happen eventually.
The catch word is Torque which twists the whole drivetrain assembly under massive load like when dumping the clutch.
Ciao,
Adrian.

Johan K

Duncan, nice avatar! Looks like it's cut from a sales brochure.

Dunasso

Jessica and I just made the Feb. 5th fun run through Colonial James Towne, Va. with The First Settlers Porsche Group. You should check out the thread by Carrera Mike. It was an awsome event.

Sten

Adrian,
Looking at the remains, it appears that the shaft the planet gears spin on has been rotating in the carrier (the hole the shaft fits into has worn oval). Eventually the planet gear has jumped out of mesh and done the damage. I'll try and get a photo and post it in the thread.
Barry