transfercase clunking np203

[zooman jones]

Hey guys I had my 78 chevy out today with the np203 part-time kit. I noticed when in park I could here a clunking noise coming from the transfercase. I put the truck in 4 wheel drive and put it reverse and it didn't really want to move. I had to give it some good throttle to move.

Do you guys think my chain is toast? I put it in 2 wheel drive and I could still here the clunking but it would move in reverse no problem. Is it still safe to drive in 2 wheel or should I just park it for now?

Is it possible to change the chain with transfercase still in the truck?

Thanks guys
Matt