I believe it is a viscous coupling but I'm still worried, the silicone fluid within the coupling can break down after being overheated. A massive speed differential between the front and rear axles could cause this.
My real worry is that is semi-fucked in a way that is fails at some future point.
In that case the centre diff is probably shagged by now. On account of the viscous fluid no longer being viscous. Fixable, but it's a big specialist job.
I believe it is a viscous coupling but I'm still worried, the silicone fluid within the coupling can break down after being overheated. A massive speed differential between the front and rear axles could cause this.
My real worry is that is semi-fucked in a way that is fails at some future point.