Usually a timing chain will last the life of the engine with normal oil changes, Are you sure you need a timing chain replacement? Timing belts need replacement about every 90,000 miles But your Pathfinder doesn't have one. The parts ( timing chain ) runs about $86 at the dealer plus any additional parts and fluids needed during the replacement procedure and the book time to replace this is 8.7 hours labor.
thanks for that reply, wow I can't believe that timing chain is only $86! We were quoted $1500.00 for parts & labor to replace the timing chain. We took it to another mechanic & he said it wasn't the timing chain that it was the transmission & that would be about $4000.00, so we don't know where to turn or what to do. The catalytic converters(2) are also out, which they estimated at $1900.00, parts, labor & 02 sensors. Anyway thanks for your help