Duramax LLY – CAMSHAFT BEARING REPLACEMENT – Bearing Replacement Procedure

1. Remove camshaft plug at rear of block (Figure 2-109).
Use long wood dowel or pipe tool and hammer to tap plug out rear of block. Discard plug afterward. It is not reusable.

2. Remove No. 2 bearing as follows:
a. Insert pilot from tool set J–33049 in No. 1 bearing (Figure 2-109).
b. Slide puller screw from tool set J–33049 through pilot and through No. 2 bearing.
c. Install adapter J–6098-11 on puller screw and seat adapter in No. 2 bearing.
d. Tighten nut on puller screw to remove bearing.

3. Remove bearings 3 and 4 as described in step 2.

4. Remove bearing No. 5 with driver handle from tool set J–6098-01 and adapter J–6098-12 (Figure 2-110).

5. Remove bearing No. 1 with driver handle and J–33049 (Figure 2-110).

CAUTION: It is extremely important that the cam bearings be properly aligned during installation. Failure to align the oil feed holes in the bearings and oil feed slots in the bearing bores, will result in engine failure.

6. Note ID numbers on new bearings. Place bearings in order to maintain correct installation sequence.

7. Mark center position of oil slot in each bearing bore with grease pencil or chalk. Place marks adjacent to each bearing bore so it is easily viewed. Make two marks for no. 1 bearing to ensure that both oil holes will be aligned.

8. Align oil hole in new No. 5 bearing with J–6098-01 alignment mark on block. Seat bearing in block with driver handle and adapter J–6098-12 (Figure 2-111).

9. Align both oil holes in new No. 1 bearing with oil holes in block (Figure 2-111). Bearing notch should be facing out and seam at 11 O’clock position. Seat bearing in block with driver handle and adapter J–33049 (Figure 2-111).

10. Check installation of bearing number 1 and 5. Verify that bearing oil holes are centered on slots in bores and that bearings are flush with edges of bearing bores. The small groove in each bearing should be towards upper part of block. Remove and reposition either bearing if misaligned (Figure 2-111).

11. Install remaining bearings, starting with No. 2, as follows:
a. Insert pilot in No. 1 bearing.
b. Slide puller screw through pilot and No. 2 bearing bore (Figure 2-112).
c. Position new bearing on adapter J–33049 (Figure 2-112).
d. Secure adapter to puller screw.
e. Align bearing oil hole with paint mark on block.
f. Tighten puller screw to draw bearing into place.
g. Verify that bearing oil hole is properly aligned.
h. Install bearings 3 and 4 in same manner.


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