Replacement Procedure:

Usage:

ENGINES3406B AND 3406C ENGINES

Problem:

Reports of early hour oil consumption and slobber may sometimes be attributed to excessive valve guide wear. This wear is generally isolated to the exhaust valve guides only.

Solution:

The worn valve guides can be replaced without removing the cylinder head. This maintains the integrity of the head to block seal. Existing service tools can be modified to do this task. See TOOL MODIFICATION and REPLACEMENT PROCEDURE.

Tool Modification:

Modify the Plate Assembly (part of the 1U9347 Valve Spring Compressor Group) as shown in Illustration 1. The Plate Assembly is used to compress all four valve springs for a cylinder at once. The modification will provide clearance with the rocker arm stands. This will allow the valve guides closest to the exhaust manifold "outboard guides" to be replaced without draining the coolant or removing the rocker arm shaft assembly.

Modify the 1U95725/8Inch Extractor (part of the 1U9570 Dowel Puller Group) as shown in Illustration 2. The inside diameter of the slotted end of the extractor must be enlarger to a diameter of 17.53 to 17.63 mm (.690 to .694 in). This diameter should be maintained to the end of the slots or 38 mm (1.5 in). The larger diameter will allow the extractor to fit over the valve guide.

Modify the 1U9577 Forcing Collar (part of the 1U9570 Dowel Puller Group) as shown in Illustration 3. The outside diameter of the collar must be reduced to 46 mm (1.8 in) for a length of 57.0 mm (2.25 in). Do not modify the end of the collar with the "knurl". This modification will provide clearance between the outside of the forcing collar and the cylinder head bridge dowel and the fuel injector nozzle adapter in the cylinder head.

Modify the 7S8859 Driver as shown in Illustration 4. The length of the bore guide pilot is shortened to 13 mm (.5 in). This will prevent the driver pilot from contacting the end of the valve when installing the guide in the cylinder head.

Replacement Procedure:

1.Remove the valve cover, base, and related components. See the appropriate Service Manual Disassembly and Assembly module.

2.If the engine is eguipped with a compression brake, remove the compression brake.

3.Remove the rocker shaft assemblies and bridges.

4.Turn the crankshaft until the pistons of the No.1 and No. 6, or No. 3 and No. 4, or No. 2 and No. 5 are at the top of the cylinder. Two cylinders may be worked on at each position. When the pistons are at the top of their travel, they can support the valves as the valve stem keepers are removed.

5.The modified plate assembly (part of the 1U9347 Valve Spring Compressor Group) can be used without removing the rocker arm stands. Special Instruction, SEHS9032, "Using 1U9347 Valve Spring Compressor Group" is included with the tooling. Use the valve spring compressor group to remove the valve keepers, rotocoil assemblies, springs, and guide washers.

6.Inspect the area for debris on top of the valve guide and excessive side to side movement of the valve stem in the valve guide. The presence of debris or valve stem movement indicate a worn valve guide that should be replaced.

7.Inspect for debris in the dowel hole in the bridge. If debris is present, clean the bridge, valve springs, rotocoil assembly, and the general area of the cylinder head.

8.If valve guides need replacing:

NOTE: Two cylinders can be worked on at one time. See Step 4.

NOTE: If the "inside" (closest to the rocker arm shaft) guides need removed, the coolant must be drained and the rocker arm shafts removed to provide clearance for the puller.

A.Slowly turn the crankshaft to position the top of the valve stem at or slightly below the top of the cylinder head.

B.Use the modified 1U9572 Extractor and 1U9577 Forcing Collar from the 1U9570 Dowel Puller Group to remove the guides.

C.Clean the valve stem. Clean the valve guide bore in the cylinder head. Clean the new valve guides (inside and the outside diameters).

D.Lubricate the inside diameter of the new valve guide and the valve stem with 8T2998 Camshaft Break-In Lubricant. Lubricate the outside diameter of the new valve guide with engine oil.

NOTE: To prevent damage to the valve during valve guide installation, slowly turn the crankshaft to raise the top of the valve stem approximately 6.4 mm (.25 in) above the top of the cylinder head.

E.Install the new valve guide over the valve stem. Seat the guide in the cylinder head with the modified 7S8859 Driver. See the appropriate Service Manual Disassembly and Assembly module.

F.Turn the crankshaft to raise the valves in the guides. Hold the valve stem and move the valve up and down, and rotate the valve in the valve guide. This will check for free movement of valve in the new valve guide and will also distribute the lubricant in the new valve guide bore.

G.Install the guide washers, springs, rotocoil assemblies, and valve keepers. Fill the recess in the top of the rotocoil assemblies with engine oil.

9.Repeat Steps 4 through 8 on the next cylinder or pair of cylinders that require valve guide replacement.

10.After all the worn valve guides are replaced, install the components removed in Steps 1, 2 and 3 in reverse order.

Please share this information with your TEPS Dealers.

Illustration 1. Dimensions for modifying the Plate Assembly (part of the 1U9347 Valve Spring Compressor Group.