6-39.1 REMOVAL. Remove the valve tappet (head installed) according to the following steps.
a. Insert wooden dowels of sufficient diameter and length into the push rod tube holes and into the top of each tappet securely. When properly installed, the dowels can be used to pull the tappets up and should not be able to be pulled out without considerable force.
NOTE
Remove only one tappet at a time.
b. Pull tappets up and wrap a rubber band around the top of the dowel rods (figure 6-48). This will prevent the tappets from dropping down when the camshaft is removed.
c. Remove the camshaft; refer to paragraph 6-40.1.
d. Insert a trough made out of plastic half pipe (PVC) to the full length of the cam bore (figure 6-49).
e. Remove the rubber band from two companion tappets. Secure the dowel for the tappet not being removed to the nearest adjoining dowel.
Figure 6-48. Retaining Valve Tappets S9233-C9-MMA-010
f. Pull the wooden dowel from the tappet bore; allow the tappet to fall into the trough.
g. Ensure the tappet is laying over (figure 6-49) in the trough before the trough is removed. Carefully pull the trough and tappet from the cam bore and remove the tappet.
h. Repeat step d through step f until all tappets are removed.
6-39.2 CLEANING AND INSPECTION. Clean and inspect the valve tappets according to the following steps.
a. Inspect the socket, stem, and face for pitting, cracks, or excessive wear. If excessive wear is noted on the face contact surface, replace the tappet.
b. Measure the valve tappet stem diameter (minimum 0.627 inch; maximum 0.629 inch).
6-39.3 REINSTALLATION. Reinstall the valve tappets (head installed) according to the following steps.
a. Insert the plastic trough the full length of the cam bore.
b. Feed the installation tool down the tappet bore and into the plastic trough (figure 6-50).
c. Feed the installation tool through the cam bores by carefully pulling the plastic trough and installation tool out of the cam bore.
d. Lubricate the tappets with Lubriplate 105. e. Insert the installation tool into the tappet.
Figure 6-49. Valve Tappet Removal
NOTE
To aid in removing the installation tool after the tappet is installed, work the tool in and out of the tappet several times prior to installation.
f. Slide the trough back into the cam bore.
g. Pull the tool and tappet through the cam bore and up into the tappet bore (figure 6-51). If difficulty is expe- rienced in getting the tappet to make the bend from the trough up into the tappet bore, due to the webbing of the block, pull the trough out just enough to allow the tappet to drop down and align itself, then pull the tap- pet up into the bore.
h. After the tappet has been pulled into position, slide the trough back into the cam bore and rotate it 1/2 turn. This will position the round side of the trough up, which will hold the tappet in place.
i. Remove the installation tool from the tappet.
j. Install a wooden dowel into the top of the tappet and wrap a rubber band around the dowel to secure the tap- pet in place.
Figure 6-50. Inserting Installation Tool into Tappet Bore
Figure 6-51. Pulling Installation Tool/Tappet through Cam Bore S9233-C9-MMA-010
k. Repeat step b through step j for all tappets. l. Reinstall the camshaft. Refer toparagraph 6-40.5. 6-40. CAMSHAFT.
6-40.1 REMOVAL. Remove the camshaft according to the following steps. Unless otherwise noted, callouts refer to figure 7-36.
a. Remove the cylinder head. Refer toparagraph 6-36.1.
b. Rotate engine on stand and remove the oil pan. Refer to paragraph 6-37.
NOTE
Keep the adjoining gear from moving when checking the camshaft backlash or the readings will be the total of both gears.
c. Prior to removing camshaft (5), measure the camshaft backlash as follows: 1. Position a dial indicator on a tooth of camshaft gear (1).
2. When checking the backlash, hold the adjoining gear (fuel pump drive) from moving.
3. Record the camshaft gear backlash. Mark the camshaft gear and crankshaft gear for further analysis if the backlash exceeds limits; gear backlash limit A is 0.003 inch to 0.013 inch. Seefigure 6-52.
4. Repeat steps 2 and 3 while holding the crankshaft gear in position. d. Remove hex head cap screws (2).
e. Remove camshaft (5) and thrust support (3) from the cylinder block. Do not drop the thrust support. f. Remove valve tappets (6).
6-40.2 CLEANING AND INSPECTION. Clean and inspect the camshaft according to the following steps. a. Clean the camshaft and gear with an approved solvent and a clean, lint-free rag.
Figure 6-52. Measuring Camshaft Gear Backlash
b. Inspect the fuel transfer pump lobe, valve lobes, and bearing journals for cracking, pitting, or scoring. c. Inspect the gear teeth for pitting and cracks at the root of the teeth.
d. Measure the bearing journals and valve lobes. Lobe diameters at peak: intake (minimum 1.861 inch; maxi- mum 1.866 inch); exhaust (minimum 1.850 inch; maximum 1.855 inch); transfer pump (minimum 1.410 inch; maximum 1.422 inch); and journal diameter (minimum 2.1245 inches; maximum 2.1265 inches).
6-40.3 CAMSHAFT GEAR. Replace the camshaft gear according to the following steps. Unless otherwise noted, callouts refer to figure 7-36.
a. Using a hydraulic press, remove gear (1) and key (4) from camshaft (5).
b. Remove any burrs and smooth rough surfaces caused by removing the gear from the camshaft. c. Reinstall key (4) in the camshaft keyway.
d. Lubricate the camshaft gear surface with Lubriplate 105. e. Heat the gear in a 250°F oven at for 45 minutes.
WARNING
To prevent injury, exercise extreme care and wear insulated gloves when handling heated solutions or metal.
f. Reinstall gear (1) onto the camshaft. Ensure the timing marks are facing away from the camshaft and the gear is seated against the camshaft shoulder.
6-40.4 CAMSHAFT BUSHING. Replace the camshaft bushing according to the following steps. Unless other- wise noted, callouts refer tofigure 7-37.
NOTE
The limit of wear on the number 1 bushing is the same as for the other bores without bushings.
NOTE
If the bores without the bushing are worn beyond the limit, the cylinder block must be replaced.
a. Replace the camshaft bushing if it exceeds the wear limit. The limit is 2.1324 inches. b. Remove camshaft bushing (14) with a bushing remover and hammer.
NOTE
Mark the cylinder block so the oil hole in the block and bushing can be aligned when the bushing is installed.
S9233-C9-MMA-010
c. Install new camshaft bushing (14) so it is even with the front face of the cylinder block. Ensure the oil holes align.
d. Measure the installed camshaft bushing. The limit is minimum 2.1295, maximum 2.1314 inches.
6-40.5 REINSTALLATION. Reinstall the camshaft according to the following steps. Unless otherwise noted, callouts refer tofigure 7-36.
a. Lubricate the camshaft bores with Lubriplate 105.
b. Lubricate the camshaft journals and lobes with Lubriplate 105.
c. Install the camshaft and gear assembly into the cylinder block up to the last journal. Ensure the timing marks are aligned.
d. Lubricate thrust plate (3) with Lubriplate 105 and install the thrust plate. e. Push camshaft (5) fully into the cylinder block.
f. Install thrust plate hex head cap screws (2). Torque the cap screws to 18 lb-ft.
NOTE
The end play is controlled by the thickness of the thrust plate and the groove in the camshaft.
g. Using a dial indicator, measure the camshaft end play. The end play limits are 0.007 to 0.011 inch.
h. Ensure the gear backlash is correct for any replaced gears. Measure the gear backlash with a dial indicator. The limits are 0.003 to 0.013 inch.