One of our most popular tools recently has been the Win 3747-123. It takes the place of the Miller 8516A, 8387, 8426 and 10102. This tool is used to work on 3.7 V6 and 4.7 V8 Chrysler engines used in many Mopar applications. The tool can be used to change out or re-install the rockers when they fall (a common problem). Or the combo tool can be used to replace broken valve spring or install valve seals. The Valve Holder is required to help prevent dropping a valve if removing the keeper depending upon the job being done. No valve holder is needed if not removing the keeper. Repair manual instructions should always be followed.

The Power Tech engine was said NOT to be a Mercedes design, however anyone that remembers working on older Chrysler engines like the slant six or the long used 318 can attest that the 3.7 and 4.7 bear no resemblance. There’s an obvious European design influence. Many specialty tools are needed compared those old classic Mopar engines.

I remember the 4.7 first being used in the 1999 Jeep Grand Cherokee. It has over head camshafts and with that a more complex timing chain and gear set-up. I remember thinking that it must be a Mercedes design.

Many people love this engine. I had a 2007 Dodge Dakota that had the 4.7 that gave me no problems at all. Full disclosure though, I traded it before it had too many miles on it. I remember several dropped rocker arms when I used to work at Carmax. All that was available back then was the expensive factory tools. Here’s a list of 4.7 vehicles that can use our Win 3747-123.

4.7 is an option in the following applications:

• 1999-2009 Jeep Grand Cherokee
• 2000-2007 Dodge Dakota
• 2000-2009 Dodge Durango
• 2002-2007 Dodge Ram 1500
• 2006-2009 Jeep Commander
• 2007-2009 Chrysler Aspen
• 2006-2007 Mitsubishi Raider

The 3.7 is basically the same engine with two less cylinders. A strong engine, however plagued with a pretty bad vibration due to an imbalance. It’s like they just chopped two cylinders off rather than designing a V6 from scratch. Many new owners of this engine think that the engine is “missing” but there’s no misfire needed for it to vibrate.

3.7 is an option for the following applications:

• 2002-2010 Dodge Ram 1500
• 2011-2012 Ram 1500
• 2004-2011 Dodge Dakota
• 2004-2009 Dodge Durango
• 2007-2011 Dodge Nitro
• 2002-2013 Jeep Liberty/Cherokee
• 2005-2010 Jeep Grand Cherokee
• 2006-2010 Jeep Commander
• 2006-2010 Mitsubishi Raider
• 2002 Dodge M80