The only 4x4 I ever had was an '82 Toyota p/u with the 22R engine. It finally threw a rod at about 190K and got "retired". About the last 50K on that truck, it had a cracked block that a friend helped me drop the oil pan and patch a curved 4"+ crack under the #4 cylinder. Despite not holding, the JB Weld slowed the oil loss to a qt. every 4-500 miles. That truck got so old (15 years) that the floor panels on BOTH sides developed fist-sized holes behind both of the front tires. Never had any mechanical problems other than the cracked block and a cracked exhaust pipe at the flange that bolted it to the manifold. We ended up having to weld that sucker twice but it worked.