C4 four wheel drive knob

[nine11speedster]

Hi everyone

Does anyone have any idea what/how exactly does this knob/dial work?

I have had the car (89 964 C4) for years and never knew how to work this...

Thanks
Carson

[Newsboy]

It locks all your wheels together , like 4 wheel drive for getting out of snow etc.. There are speed limitations, so only use it when needed.

[group911@aol.co]

Carson
Like he said, it locks up front and rear differentials. It should disengage automatically above a certain speed.
Can't remember what speed that is but it's pretty low.

[59 burst]

PDFD - porsche dynamic four wheel drive I think. As stated previously , it’s to get unstuck from sand , snow and not for shift on the fly. Normally , C4 send 31%. power to front axle and 69% to rear but engaging Traction program ( clockwise rotation) allows equal power front & rear as diffs are locked up.
Works up to 18 mph and auto release around 25 mph. You don’t want to normally drive around engaged in this mode as handling will suffer greatly. It is for getting car unstuck. I read this system was adopted from 959 - rally anyone. I’ve never tested mine and don’t plan on it. BTW, I believe the modern 4’s still start out with this 31/69 split and varies accordingly. At least my 991.1 did.

[r-mm]

Can be used to (slowly) bleed the diff locks if you don't have a PDT999 / Hammer