This article is a work in progress that we started to cover important information about various accessory drive setups on 6.2 and 6.5L diesel engines

V-Belt water pumps are all REVERSE rotation vs serpentine belt configurations and are not cross compatible

These model years have the early serpentine drive setup with a driver side alternator and passenger side AC compressor

1. Forgetting the spacer/engine lift bracket on the driver side cylinder head. This bracket spaces out the power steering pump and alternator and is easy to forget

2. Forgetting the rear alternator support brace that attaches the alternator to 2 of the intake manifold bolts

   1. Alternator will eventually break and crack the housing from excessive vibration

3. Incorrect alternator pulley size causes wrong RPM reading on dashboard

   1. Get the correct pulley from us! https://quadstartuning.com/products/6-5l-alternator-pulley

4. Belt slack/slop

   1. Many replacement tensioners are not up to the task for a diesel engine. Our HD tensioner addresses this

      1. https://quadstartuning.com/products/6-5l-heavy-duty-belt-tensioner-1

5. AC Compressor leaks

   1. The factory R4 AC compressor on early serpentine drives suffers from a design flaw where the torque of the mounting bolts warps the housing and they all fail over time

      1. There are upgraded scroll compressors available that address this and update to a more modern design

This image shows the engine lift bracket that's often forgotten on early serpentine belt setups

This image shows belt routing options for the early serpentine drive

These model years have the late serpentine drive setup with a driver side AC compressor and passenger side Alternator(s)

This setup is more robust than the early serpentine drive

1. Water Pumps

   1. The water pump was changed multiple times

      1. 1996 thru early 1999 used a bolt on fan clutch

         1. 1997 changed to a higher output water pump that still utilized the bolt on fan clutch

      2. Mid year 1999 and later changed to a threaded, spin-on fan clutch and the highest output water pump

2. AC Compressor leaks and performance

   1. An upgraded scroll type AC compressor is available for these also.

      1. It's a simple upgrade that comes with 4 spacer washers to lift it up slightly and get the correct belt spacing so don't forget to use those

3. Belt Tensioner Quality

   1. Many replacement tensioners aren't up to the task

      1. Quadstar Has your fix! https://quadstartuning.com/products/6-5l-heavy-duty-belt-tensioner-1