I have a 2000 forester with a 5MT and to my knowledge I have the viscous diff. I am pretty sure the center diff is bad. It has the right symptoms, once it is warmed up it will clunk when I turn hard at slow speeds. I am wondering how much does a fried center diff effect the whole AWD system? As far as I can tell the AWD is working, but I don't know how much it is working.

 

thanks

-Lance

It isn't great. Basically the center diff is locking. So it's like leaving an old subau or truck in 4wd and driving it on pavement. It's hard on the tires, axles, tranny, etc.

I ran mind for three months with minor symptoms (i.e. only binding under hard lock turns) before I finally replaced it with a new viscous coupler. It took that long for me to give up on trying to find a good used one.