I'm a newbie here and need some advice: My '94 fj80 with 97k on it has a strange habit of locking up the center diff (as if it's in 4L) after drives at hwy speeds of at least an hour or more. My best guess is something is heating up inside the transfer case and is forcing an artificial engaging of 4L. This makes it very difficult to turn at low speeds and I'm afraid I'm putting significant wear on something when I do. When I suggested replacing the viscous coupling unit, the dealer kind of looked at me funny and said "we don't do that -- we'd only replace the whole transfer case." At about $4,000!! They could also do an "overhaul" which would run more like $3,000. Spending this kind of money could get me a head start on a newer LC. I'm wondering if anyone could shed some light on this or suggest a less expensive, yet effective, fix. I'd like to keep the truck for quite a while longer (I'm not a big fan of leather interior on newer models and I like the relative simplicity of the 80 vs. the new 100s). Many thanks in advance!