Dodge Nitro. Manual - part 115

The upper main bearing (2) has a oil feed hole and a center groove to allow lubrication of the main journal and 
must be properly positioned in the block. 

MAIN BEARING SELECTION CHART 

CRANKSHAFT DIAMETER 

BLOCK MAIN BORE DIAMETER 

BLOCK MAIN BORE GRADE 

REMOVAL 

BEARING -CRANKSHAFT MAIN 

surface. See Fig. 189. For verification, refer to for number to size identification.

Crankshaft Main Journal 
Grade Marks  
Each bearing grade increment of 
0.003 mm is for wall thickness 
so diametrical clearances are 
adjusted 0.006 mm per select fit 
class

Main Bearing Bore Grade Marks 

 

1 

2 

3 

A 

(3) Standard

(2) +003 mm 
(+0.0001 in.)

(1) +0.006 mm 

(+0.0002 in.)

B 

(4) -0.003 mm (-

0.0001 in.)

(3) Standard

(2) +003 mm 
(+0.0001 in.)

C 

(5) -0.006 mm (-

0.0002 in.)

(4) -0.003 mm (-

0.0001 in.)

(3) Standard

 

Crankshaft Diameter (mm)

Min

Max

Grade

63.9870 mm

63.9956 mm

A

63.9957 mm

64.0042 mm

B

64.0043 mm

64.0130 mm

C

 

Block Main Bore Diameter 

(mm)

Min

Max

Grade

68.9895 mm

68.9964 mm

1

68.9965 mm

69.0034 mm

2

69.0035 mm

69.0105 mm

3

Crankshaft Journal Grade 

 

Block Main Bore Grade 

 

1 

2 

3 

A 

Class 3

Class 2

Class 1

B 

Class 4

Class 3

Class 2

C 

Class 5

Class 4

Class 3

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

Fig. 190: Main Bearing Cap Identification 
Courtesy of CHRYSLER LLC 

Bearing caps are not interchangeable and are marked to insure correct assembly. See Fig. 190. Upper and lower 
bearing halves are NOT interchangeable. 

1. Remove oil pan. See REMOVAL.  

2. Remove oil pick-up tube and windage tray.  

3. Identify bearing caps before removal. See Fig. 190. 

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

Fig. 191: Removing/Installing Upper Main Bearing With Special Tool C- 3059 
Courtesy of CHRYSLER LLC 

4. Remove bearing caps one at a time. Remove upper half of bearing by inserting Main Bearing Tool C-

3059 into the oil hole of crankshaft. See Fig. 191.  

5. Slowly rotate crankshaft clockwise, forcing out upper half of bearing shell.  

INSTALLATION 

BEARING -CRANKSHAFT MAIN 

1 - SPECIAL TOOL C-3059
2 - BEARING
3 - SPECIAL TOOL C-3059
4 - BEARING

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro

  

Fig. 192: Main Bearing Identification 
Courtesy of CHRYSLER LLC 

Bearing caps are not interchangeable and are marked to insure correct assembly. Upper and lower bearing 
halves are NOT interchangeable. See Fig. 192. 

When installing a new upper bearing shell, slightly chamber the sharp edges from the plain side.

CAUTION: Main bearings are select fit. See STANDARD PROCEDURE. 

NOTE:

Only one main bearing should be selectively fitted while all other main bearing 
caps are properly tightened.

 

2007 Dodge Nitro R/T 

2007 ENGINE 4.0L - Service Information - Nitro