However, if you're determined to do it yourself, here's a general overview. This is not a complete, step-by-step guide, and omitting crucial steps can cause serious engine damage. Consult a repair manual specific to your 1999 Ford Explorer's engine (either the 4.0L SOHC or the 4.0L OHV – the procedure differs slightly). A Haynes or Chilton manual is a good investment.
General Steps (Consult your repair manual for precise details and torque specifications):
1. Safety First: Disconnect the negative battery terminal. Properly support the vehicle on jack stands.
2. Access: Remove components that obstruct access to the timing belt, including:
* Serpentine belt
* Air intake components
* Various covers and pulleys
3. Identify Timing Marks: Locate the timing marks on the crankshaft, camshaft(s), and possibly the balancer shaft (if applicable). These marks are crucial for proper alignment. Take pictures before disturbing anything.
4. Tensioner Release: There's usually a tensioner pulley that needs to be released to remove the timing belt. This may involve using a special tool (often a specific socket or wrench) to compress the tensioner or turn it to a specific position.
5. Belt Removal: Carefully remove the old timing belt, paying attention to the orientation of the belt and its routing around the pulleys.
6. Installation of New Belt: Install the new timing belt, ensuring it's properly seated on all pulleys and aligned with the timing marks. You'll likely need to re-tension the belt using the tensioner.
7. Tensioner Re-engagement: Once the new belt is installed and aligned correctly, re-engage the tensioner pulley.
8. Reassembly: Reinstall all removed components in reverse order. Pay close attention to proper torque specifications for all bolts and nuts.
9. Verification: Rotate the engine by hand (a few revolutions) to ensure the timing marks remain aligned and there are no interference issues.
10. Final Check: Reconnect the battery, and start the engine. Listen for any unusual noises. Check for leaks and inspect for proper belt tension.
Crucial Considerations:
* Engine Type: The 4.0L SOHC and 4.0L OHV engines in the 1999 Ford Explorer have different timing belt configurations and procedures. You MUST use a repair manual specific to your engine type.
* Tools: You'll need a variety of tools, including sockets, wrenches, ratchets, a torque wrench (absolutely essential), and potentially specialized tools for the tensioner.
* Timing Marks: Misaligned timing marks can cause serious engine damage. Take your time and double-check everything.
* Water Pump: Many mechanics recommend replacing the water pump at the same time, as it's often driven by the timing belt and may fail soon after.
Disclaimer: This is a simplified overview and should not be considered a complete guide. Incorrectly performing this repair can cause irreparable engine damage. Always refer to a repair manual specific to your vehicle for detailed instructions and safety precautions. If you are not comfortable with this level of repair, please take your vehicle to a qualified mechanic.
