* Rear Main Seal: This seal prevents oil from escaping where the crankshaft exits the engine block. It's a common failure point on many vehicles, including Rangers of this era. Given the extensive oil coverage, this is a strong suspect.
* Valve Cover Gasket(s): While less likely to cover the *entire* undercarriage, a severely leaking valve cover gasket can contribute significantly to the problem, especially if combined with another leak.
* Oil Pan Gasket: A leaking oil pan gasket will cause oil to pool under the engine. The extensive coverage suggests this might be contributing, but probably isn't the sole cause.
* Crankshaft Seal (front): Less likely to coat the entire undercarriage, but possible.
* Timing Cover Seal: A leak here would likely cause oil to run down the front of the engine. Again, less likely to be the *sole* cause of the extensive leak.
* Oil Filter: While less common, a faulty oil filter could contribute.
Important Note: It's nearly impossible to diagnose the exact source of the leak without a thorough visual inspection. The oil might be traveling down from a higher point, making it difficult to pinpoint the origin.
What you should NOT do:
* Continue driving the truck: Driving with a significant oil leak risks serious engine damage due to low oil pressure.
What you SHOULD do:
1. Stop driving the truck immediately. This is crucial to prevent catastrophic engine failure.
2. Find a qualified mechanic: A professional mechanic can accurately diagnose the problem and provide a repair estimate. They have the tools and experience to locate the leak's source.
3. Consider the cost of repair vs. the value of the vehicle: A major engine seal repair can be expensive. Depending on the age and overall condition of the truck, it might be more cost-effective to sell it as-is or for parts rather than investing in a significant repair.
Do not attempt a DIY repair unless you have significant automotive experience. These leaks often require specialized tools and techniques to properly address.
