4 Wheel Drive Problem

[cleetus]

Hello

I have a Hilux 2.5lt D4D 52 plate with 230,000 on the clock. The problem I have is the gear box seems to keep trying to put its self in to 4 wheel drive. A while back first gear went so we replaced the gear box with one that had done 50 miles and had come from a vehicle which had been written off on the transporter. Both the old and now the replacement gear box both had the same problem. Is it the gear box? The problem dosn't happen all the time, just when it feels like it.

Any help in this matter would be very helpfull