Check Valve Ball Removal From Oil Galleries:

The following procedures can be used (as required) to remove the check valve ball from engine oil galleries.
These procedures (A through C) are listed in sequence and should be followed accordingly.

Procedure A.

1. Insert a narrow magnet (or screwdriver with a magnet) on top of the screwdriver shank) into the check valve bore in the block.


2. If magnet contacts ball check, ball can be removed.

Procedure B

1. Remove timing chain housing from engine compartment and remove front oil gallery plug. Refer to Service Manual.

2. Insert a narrow magnet with flexible handle into the front oil gallery. Push the magnet to the end of the gallery. If magnet contacts ball check, ball can be removed.

Procedure C

1. Drain oil and remove oil pan. Refer to Service Manual.

2. With timing chain housing and front oil gallery plug removed, insert magnet into gallery approximately 1 inch to position magnet over Number 1 bearing oil feed passage.

3. Remove Number 1 main bearing cap.

4. Rotate crankshaft so the oil feed hole in Number 1 main journal is approximately at the 4:00 o'clock position as viewed from the front (crankshaft snout end) of the engine.

IMPORTANT:

Placing the crankshaft main journal oil feed hole at the 4:00 o'clock position allows the journal hole to line up with the oil hole in the upper bearing.

5. Verify that the oil feed hole in the crankshaft journal is lined up with the hole in the upper bearing by inserting a small plastic straw thru the crankshaft journal and bearing oil feed hole.

NOTICE:

Do not use a metal tool to align the crankshaft journal and upper bearing hole or bearing damage could result.

Important: When the crankshaft journal and upper bearing oil holes are aligned, the ball check (if in the main bearing oil feed passage) may be visible when looking through the crankshaft journal hole.
6. With a rubber tipped air gun, blow compressed air through Number 1 crankshaft main bearing journal oil feed hole to force ball to magnet.

If ball cannot be located, repeat procedure C, steps 3 through 6 at the other crankshaft main journals in sequence of 5, 4, 3, 2 until the ball is recovered.

PARTS INFORMATION

Parts required to perform the repair described in this bulletin are listed below. Parts are currently available through GMSPO.

DESCRIPTION PART NUMBER

Oil Flow Check Valve 22548701
Gasket Kit, Cylinder Head 22535452

WARRANTY INFORMATION:

Labor Operation Number: J0509
Labor Time : 6.9 hrs Add:

A - Remove Ball from Top of Block .1
B - Remove Ball from Front Oil Gallery Plug .3
C - Remove Ball from # 1 Crankshaft Oil Passage .8
D - Remove Ball from # 5 Crankshaft Oil Passage .3
E - Remove Ball from # 4 Crankshaft Oil Passage .3
F - Remove Ball from # 3 Crankshaft Oil Passage .2
G - Remove Ball from # 2 Crankshaft Oil Passage .2
H - To clean parts on vehicles over 30,000 miles
if necessary .4