4.0L Timing Chains

[Shawn Alexander 2]

I'm performing timing chain replacements on a 2002 ST. This is my first time. The deeper I go, the more work it needs! All three chain tensioners need replacement. Since the plastic tensioners grenaded, the oil pan and lower crank apron had to come off so I could dig out all the fragments. I wanted to do this one complete, thorough and right, and then decide if the time and money are worth it.

 

[Robert Howell]

Did that repair a several years ago. Since then I also replaced that stupid plastic thermostat housing with an aluminum one. This 4.0 now runs like a Swiss watch.

I think the cost of the new cassettes, counter balance chain, gaskets, plugs (cause the engine was out), and vacuum hoses was well worth the extra 6 years we got (and getting) out of this little truck. I can't wrap my head around the $50,000 + CDN dollars to replace her with a new small truck of some flavour.

In the end, I think you'll find it worth the hassle.

 

[Doug Menkhaus]

Same here. I had to pull my '02 4.0 L out because of a locked up oil pump and snapped oil pump drive shaft. I inititally was just going to replace the pump and shaft, but a friend chided me when he said "You're going to pull the engine and NOT replace the timing chains?!"



He was right. I replaced all the chains and cassettes, and after getting the engine back in, I was amazed at how quiet it was. I could literally hear the injectors firing once I started it.



Hollyman, where can I get an aluminum housing?

 

[Robert Howell]

Here is the link to that repair

 

[Bill Byars]

If you haven't discovered this yet, you have to borrow or buy the special timing tools to time up the engine, it isn't like the old ones where you can just line up the dots on the gears, as there none.