Camshaft Journals

Cleaning

1. If not done as part of engine disassembly, remove camshaft center bearing (6262) or gear from camshaft (6250) and camshaft from engine (6007) as outlined in Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).

2. Clean the camshaft in an appropriate solvent and wipe it dry.

3. Remove light scuffs, scores, or nicks from the camshaft machined surfaces with an oil stone.

Inspection

Inspect the camshaft journals and lobes for scoring and signs of abnormal wear.

Lobe pitting, except in the general area of the lobe toe, is not detrimental to the operation of the camshaft. The camshaft should not be replaced unless lobe lift loss has exceeded the specifications or pitting has occurred in the lobe lift area. Refer to Camshaft Journals, Cam Lobe Lift in this section.

Camshaft Runout

NOTE: Check camshaft journals for out of round before checking for runout, or an out of round condition on the center journal could be confused for an excess runout condition.

1. Set suitable V-blocks on surface plate. Support outer camshaft journals on V-blocks.

2. Set up Dial Indicator with Bracketry TOOL-4201-C or equivalent to check center bearing journal.

3. Zero dial indicator.

4. Slowly rotate camshaft to determine overall runout. If runout exceeds 0.03mm (0.0012 in.), replace camshaft.

   

Cam Lobe Lift (Camshaft Removed)

There are two ways of measuring cam lobe lift with the camshaft removed, with a vernier caliper camshaft or on a lathe or cam grinder with a dial indicator. The second method is more accurate.

With Calipers

1. Inspect camshaft as outlined in this section.

2. Measure the distance of each cam at the major diameter.

3. Measure the distance of each cam at the minor diameter.

4. For each cam, subtract the minor diameter from the major diameter. The result for each lobe is the lobe lift.

5. Check the lobe lift for each cam against the specifications in Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).

6. If any cam is worn excessively, the camshaft and valve tappet (6500) will have to be replaced.

   

On a Camshaft Grinder or Lathe

1. Clean and inspect the camshaft as outlined in this section.

2. Install the camshaft on the lathe or camshaft grinder centers.

3. Position the dial indicator which comes with the machine at the heel of the cam which you are going to check.

4. Zero the dial indicator.

5. Slowly turn the camshaft until the point of the dial indicator is on the tip of the cam.

6. Read the dial indicator. This is your cam lobe lift.

7. Check the lobe lift against the specifications in Section 03-01A (4.9L SFI), Section 03-01B (5.0 and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel). If any cam is excessively worn, the camshaft and valve tappet will have to be replaced.

Camshaft Bearings

1. If engine has not been disassembled and cleaned, wipe bearing bore clean with a clean rag and solvent. Dry with a clean rag.

2. Inspect for scoring and visible wear. Inspect if babbitt has been worn away to base. If visibly worn or damaged, bearings will have to be replaced. If one of the center bearings is worn significantly more than the end bearings, check camshaft for excessive runout.

3. Using suitable bore gauge or inside micrometer, measure each bearing twice, 90 degrees apart, to determine bearing size and out of round.

4. Check results against specifications in appropriate Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel). If bearings are out of specifications, they will have to be replaced. Check camshaft journals before replacing bearings to determine if undersize bearings are required.

5. If necessary, replace bearings as outlined in Section 03-01A (4.9L SFI), Section 03-01B (5.0 and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).

Camshaft Journal Oil Clearance

1. Measure camshaft bearings and camshaft bearing journals as outlined in this section.

2. Subtract size of journal from the size of its bearing.

3. Check clearance against specifications in Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).

4. If clearance is excessive, but camshaft journals are within specifications, simply install new bearings. If both bearings and journals are worn, turn camshaft journals to a standard undersize and install new bearings.

Camshaft Journal Diameters

1. Measure each journal twice, 90 degrees apart, to determine journal wear, size, and out of round.

2. Check measurements against specifications in Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).

3. If journals are excessively out of round or worn, regrind to a standard undersize. Refer to Master Parts Catalogue. If journals are too worn to be refinished to an available undersize, camshaft will have to be replaced.

Camshaft Sprocket

Inspect camshaft sprocket or gear for worn or broken teeth. If a gear (4.9L), check backlash as outlined in this section. If necessary remove as outlined in Section 03-01A (4.9L SFI), Section 03-01B (5.0L and 5.8L MFI), Section 03-01C (7.5L MFI) or Section 03-01D (7.3L diesel).