The 80 Series Land Cruiser is one of the most popular four wheel drives, even today. Even though the first models are over 20 years old, they are still very common and for a number of reasons. However, one of the issues with the 80 Series Land Cruiser is the sloppiness that develops over a long, hard life. These Land Cruisers are full time four wheel drive, which means that the engine powers all four wheels even when you are driving on bitumen. This puts a lot more wear and tear on various components, and you end up with slop.
To see if you have it, coast along a road, and put your accelerator flat to the floor, then release it all the way very quickly, and put it flat to the floor again. If your vehicle makes a nasty noise, or shakes forwards and backwards then you have found it! Land Cruisers that have done a large number of kilometres (say over 300,000) are the most prone to this problem, and today most of them have done well over that.
One of the best ways to remove this slop is to get rid of the centre differential. This splits the power from the front of the vehicle to the rear, but on road full time four wheel driving is not that great. By fitting a part time kit, you install manual locking hubs at the front, and remove the centre differential. This is replaced with a spool, and now your Centre Diff Lock button becomes the four wheel drive button.
You will find on road that the vehicle handles better, especially in the steering department! Other advantages are less wear and tear, better fuel economy, and a more natural feeling vehicle. When you go off road, its easy to engage 4WD and away you go. The amount of fuel you save may vary from case to case, but you are effectively not driving the front tail shaft, differential and axles. This creates less heat and uses less energy, thus the reduced fuel bill!
If you have an 80 Series Land Cruiser with ABS, you may want to think the part time kit over before making a decision. The ABS that came with some of the newer 80 Series Land Cruisers gets disabled when you have the vehicle in part time. This may make it illegal on road, and if you get caught with it then there could be trouble!