Turbo Inspection Procedures: Dodge Ram 5.9L Diesel Engine

A series of actions should be conducted when visually examining a turbocharger and exhaust manifold gasket surfaces for possible damage. Use the following turbo inspection procedures for turbine powered 5.9 liter engines.

NOTE: While these turbo inspection procedures can be applied to most turbocharged vehicles. The exact measurements listed only apply to the 2001, 2002, 2003, 2004 Dodge Ram 5.9 liter diesel trucks.


1. Check the mounting studs and replace any corroded or stripped studs.

  • Visually check the turbocharger for damage or cracks. The following cracks should not be considered passable:
  • Cracks existing in the compressor housing and the turbine that fully go through.
  • Cracks that measure more than 0.6 in. (15 mm) on the turbo’s mounting flange.
  • Cracks that intersect bolt through-holes on the turbocharger mounting flange.
  • Two cracks existing on the turbo’s mounting flange that are within .025 in. (6.4 mm) to each other.

2. Carefully examine the turbo compressor wheel fins and the impeller for damage, this includes chips, nicks or cracks. It should be noted that on some Dodge Ram turbos a paint mark was placed on the impellers during the manufacturing process. This paint mark often appears to be a crack after normal operation. Verify this mark is not a crack by using a suitable solvent to remove the mark.

3. Look closely at the turbo’s compression housing for signs of impeller contact. A rubbing impeller condition will create scuff marks. If scuffing exist replace the turbo.

Check compressor housing for signs the impeller is rubbing agains the housing.
Impeller Rubbing Against Housing

4. Measure the turbo’s axial end play using a dial indicator. Be sure to zero the indicator at one end of travel. Then measure the impeller shaft by moving the shaft fore and aft. Keep a written measurement of the results.

How to measure shaft play, also termed turbo axial end play.
Measure Axial End Play

Specifications for 2001-2002 models: Tolerable end play would be as follows: 0.0015 in. (or 0.038 mm) minimum and 0.0035 in. (or 0.089 mm) maximum. Replace the turbo assembly if the recorded measurement does not fall within these specifications.

Specifications for 2003-2004 models: Tolerable end play would be as follows: 0.0001 in. (or 0.026 mm) minimum and 0.005 in. (or 0.127 mm) maximum.

5. Insert a narrow wire style feeler gauge between the turbo housing and the compressor wheel so that you can effectively measure the bearing radial clearance. Then, without applying to much pressure, push the turbocharger compressor wheel in the direction of the housing. Keep a written record of the clearance measurement. Next place the feeler gauge in the exact location and carefully push the turbo compressor wheel in the opposite direction and record the clearance. Lastly, subtract the smallest clearance measurement from the largest measurement. The end result is the radial bearing clearance.

Measure the turbo bearing radial clearance on Dodge Ram 5.9 engine.
Measure Bearing Radial Clearance

Specifications for 2001-2002 models: Acceptable radial bearing clearance is any number that falls between 0.0128 in. (or 0.326 mm) minimum and 0.0195 in. (or 0.496 mm). Replace the turbo assembly if measurements fall outside these parameters.

Specifications for 2003-2004 Models: Acceptable radial bearing clearance is any number that falls between 0.013 in. (or 0.33 mm) minimum and 0.020 in. (or 0.50 mm) maximum. If measurements fall outside these parameters, replace the turbo assembly.

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