Dodge Nitro. Manual - part 104

STANDARD PROCEDURE 

HYDRAULIC LASH ADJUSTER BLEEDING 

Fig. 155: Rocker Arm Positioned On Base Circle Of Camshaft 
Courtesy of CHRYSLER LLC 

as necessary.

6. Worn valve guide(s).

6. Ream guide(s) and replace valve(s) with oversize 
valves and seal(s).

7. Air injected into oil due to broken or cracked oil 
pump pickup tube.

7. Inspect pickup tube and replace as necessary.

8. Collapsed lash adjuster due to debris injection.

8. Clean debris from engine and replace lash 
adjuster/rocker assembly*.

9. Intake rocker arm roller clevis ear(s) contacting 
camshaft bearing journal(s) on side.

9. Inspect camshaft end play and all valve train 
components for wear. Replace as necessary.

*Lash adjusters are serviced with the rocker arms-do not disassemble. 

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

Use this procedure to manually bleed aerated oil from the lash adjuster and remove sponginess. 

1. Run the engine, bringing it to operating temperature in order to freshly pressurize and warm the 

valvetrain system oil supply.  

2. Remove cylinder head cover(s).  

3. Ensure the rocker arm is positioned on the base circle (1) of the cam. See Fig. 155. Rotate engine as 

necessary. 

Fig. 156: Special Tool 8351, Service Access Hole, Rocker Arm, Check Ball, Valve Tip & Lash 

1 - CAMSHAFT BASE CIRCLE
2 - HIGH-PRESSURE CHAMBER

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

Adjuster 
Courtesy of CHRYSLER LLC 

4. For intake rocker arm positions: 



Adjust Special Tool 8351 (1) Release Probe's gauge pin to extend approximately 20 mm (0.787 
in.). Then, carefully insert the release probe gauge pin into the lash adjuster (6) service access hole 
(2). See Fig. 156. 



Gently unseat lash adjuster's internal check ball (4).  



While the internal check ball (4) is held unseated, press the rocker arm (3) into the valve tip (5), 
allowing the lash adjuster (6) to fully collapse. Hold this fully collapsed position for about one 
second, or longer.  



Slowly release the rocker arm (3), thereby allowing the (6) to extend, which in turn refills the high 
pressure chamber with non-aerated oil.  



Remove probe to allow check ball (4) to seat.  



Recheck for sponginess. If the lash adjuster (6) sponginess is not completely or nearly eliminated, 
then repeat procedure.  



If the spongy condition cannot be removed, replace effected rocker arm(s) (3).  

5. For exhaust rocker arm (3) positions: 



Adjust Special Tool 8351 (1) Release Probe gauge pin to extend approximately 20 mm (0.787 in.). 
Then, using two release probes, carefully insert gauge pins into the lash adjuster service access 
holes. See Fig. 156. 



Gently unseat BOTH lash adjuster's internal check ball (4) at the same time.  



While the internal check ball (4) is held unseated, press the rocker arm (6) into the valve tip, 
allowing the lash adjuster to fully collapse. Hold this fully collapsed position for about one second, 
or longer.  



Slowly release the rocker arm (3), thereby allowing the lash adjuster (6) to extend, which in turn 

1 - SPECIAL TOOL 8351
2 - OIL AIR RELIEF SERVICE ACCESS HOLE
3 - ROCKER ARM ASSEMBLY
4 - INTERNAL CHECK BALL
5 - VALVE TIP
6 - HYDRAULIC LASH ADJUSTER WITHIN ROCKER 
ARM

CAUTION: If probe tip (1) breaks off within the lash adjuster (6), replace the 

affected rocker arm (3).

CAUTION: If probe tip (1) breaks off within the lash adjuster (6), replace the 

affected rocker arm (3).

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

refills the high pressure chamber with non-aerated oil. 



Remove probes (1) to allow check balls (4) to seat.  



Recheck for sponginess. If the lash adjuster (6) sponginess is not completely or nearly eliminated, 
then repeat procedure.  



If the spongy condition cannot be removed, replace effected rocker arm(s) (3).  

6. Install cylinder head cover(s).  

REMOVAL 

SHAFT -ROCKER ARMS 

Fig. 157: Rocker Arms & Shafts 
Courtesy of CHRYSLER LLC 

1. Remove cylinder head covers. See REMOVAL)  

2. Identify the rocker arm assembly and rocker arms before disassembly. See Fig. 157.  

3. Remove rocker arm assembly bolts.  

4. Remove rocker arm assembly.  

CAUTION: The rocker arm shafts are hollow and are used as lubrication oil passages. 

The rocker arm and shaft assembly on the RIGHT side of the engine has 
an oil passage hole from the cylinder head to the third rocker shaft 
support. The rocker arm shaft assembly on the LEFT side of the engine 
has an oil passage hole from the cylinder head to the second rocker shaft 
support.

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro