Looking to buy a 2001 4x4 Exploder with 140K miles. It has the timing chain rattle these engines are famous for. It is of course ineligable for the warranty recall that would fix it for free. The PO put new tensioners on the front and back chains, but that did not fix the problem. I've read in some posts that there are revised parts that will fix this problem. My question is, what exactly will I need to purchase in order to swap in the good parts, and at approximately what cost?
I understand that I'll have to pull the motor to do this also?
Any info is apriciated. I will be negotiating this week, and would like to know what I'm getting into in advance. Thanks

 

I'm not really well-versed on the 4.0 SOHC engines, but here's the TSB on it. I put the section about required parts in bold font:

Engine - 4.0L SOHC - Rattle noise from primary chain drive area between 2K-3K RPM - Cold engine operation only

Noise - Rattle noise from primary timing chain drive area between 2K-3K RPM - Cold engine operation only - vehicles equipped with 4.0L SOHC Engine only

Ford: 99-02 Explorer, 01-02 Sport Trac, Explorer Sport, Ranger
Mercury: 99-02 Mountaineer

Issue:

Some vehicles equipped with the 4.0 SOHC (Single Over-Head Cam) engine may exhibit a Primary Timing Chain rattle noise. The noise is audible during hot and cold engine operation (but predominantly found on cold engines) under acceleration, typically at 2400-2500 rpm. To confirm presence of this noise, accelerate in 2nd gear between 2000-3000 rpm and listen for rattle noise that sounds similar to spark knock. This may be caused by the Primary Timing Chain Tensioner system.

Action:

Replace the Primary Timing Chain Tensioner, Chain Guide, Jackshaft, and Crankshaft Sprockets with a Primary Timing Chain Tensioner Kit. The kit includes an improved Primary Chain Tensioner, as well as updated Primary Chain Guide, Jackshaft, and Crankshaft Sprockets. Required fasteners, primary timing chain, and front cover gaskets are also included. Refer to the following Service Procedure for details.

Service Procedure:

Verify the condition. Obtain the correct kit and follow the sheet supplied with the kit.

Use kit 2U3Z-6D256-AA (balance shaft engines) for:
-99-01 4x4 Explorer/Mountaineer
-01-02 4x4 Sport/Sport Trac
-All 02 Explorer/Mountaineer, except engine codes 2G-960-AA and 2G-964-AA

Use kit 2U3Z-6D256-BA (non balance shaft engines) for:
-99-01 4x2 Explorer/Mountaineer
-01-02 4x2 Sport/Sport Trac
-02 Explorer/Mountaineer with engine codes 2G-960-AA and 2G-964-AA
-All 2001-02 Ranger

Labor Time: Estimated around 6 hours