Buick Enclave: Camshaft
* PLEASE READ THIS FIRST *
NOTE: Examples used in this article are general in nature and do not necessarily relate to a specific engine or system. Illustrations and procedures have been chosen to guide mechanic through engine overhaul process. Descriptions of processes of cleaning, inspection, assembly and machine shop practice are included.
Always refer to appropriate engine overhaul article, if available, in the ENGINES section for complete overhaul procedures and specifications for the vehicle being repaired. Camshaft service depends heavily on the exact engine design, bearing layout, lubrication path, timing system, and valve train configuration. When this information is used for a Buick Enclave engine overhaul, it should be treated as a practical process guide, while all final measurements and installation steps must come from the correct engine-specific procedure.
CLEANING & INSPECTION
NOTE: Examples used in this article are general in nature and do not necessarily relate to a specific engine or system. Illustrations and procedures have been chosen to guide mechanic through engine overhaul process. Descriptions of processes of cleaning, inspection, assembly and machine shop practice are included.
Always refer to appropriate engine overhaul article, if available, in the ENGINES section for complete overhaul procedures and specifications for the vehicle being repaired.
Clean camshaft with solvent. Ensure all oil passages are clear. Inspect cam lobes and bearing journals for pitting, flaking or scoring. Using micrometer, measure bearing journal O.D. The camshaft should be handled carefully during cleaning because the lobes and journals are precision-machined surfaces. Any grit, dried oil, metal particles, or solvent residue left in oil passages can damage the camshaft bearings, lifters, followers, or cam journals after the engine is started.
Inspect each lobe under good lighting and compare the wear pattern from one lobe to the next. A healthy lobe should show smooth, even contact without sharp edges, abnormal flattening, heat discoloration, cracks, or surface breakdown. If one lobe is damaged, inspect the matching lifter, follower, rocker arm, or tappet because paired components often fail together.
Support camshaft at each end with "V" blocks. Position dial indicator with tip resting on center bearing journal. The supports must be clean and stable so the dial indicator reading reflects actual camshaft runout rather than movement in the test setup. Place the indicator tip squarely on the journal surface and rotate the camshaft slowly.
Rotate camshaft and note camshaft runout reading. If reading exceeds specification, replace camshaft. Excessive runout can cause uneven bearing loading, oil clearance problems, timing irregularities, and abnormal valve train wear. A camshaft that is bent or distorted should not be reused simply because the lobes appear serviceable.
Check cam lobe lift by measuring base circle of camshaft using micrometer. Measure again at 90-degree angle to tip of cam lobe. Cam lift can be determined by subtracting base circle diameter from tip of cam lobe measurement. Measure carefully and record each lobe separately, because intake and exhaust lobes may have different dimensions. A worn lobe may reduce valve lift enough to cause power loss, misfire, rough idle, or poor cylinder filling.
Different lift dimensions are given for intake and exhaust cam lobes. Reading must be within specification. Do not compare intake and exhaust readings as though they should always match. The correct comparison is between the measured lobe and the specification for that exact lobe type and engine location.
Replace camshaft if cam lobes or bearing journals are not within specification. Reusing a camshaft with worn lobes or damaged journals can quickly damage new lifters, bearings, or followers. During Buick Enclave engine service, camshaft condition should be considered together with oil pressure history, valve train noise, metal contamination, and any previous timing or lubrication failure.
Inspect camshaft gear for chipped, eroded or damaged teeth. Replace gear if damaged. On camshafts using thrust plate, measure distance between thrust plate and camshaft shoulder. Replace thrust plate if not within specification. Gear damage can affect valve timing accuracy and may also introduce metal debris into the engine. If the thrust plate is worn, the camshaft may move forward and rearward beyond the allowed range, causing timing variation, noise, or accelerated wear at the thrust surface.
CAMSHAFT BEARINGS
NOTE: Examples used in this article are general in nature and do not necessarily relate to a specific engine or system. Illustrations and procedures have been chosen to guide mechanic through engine overhaul process. Descriptions of processes of cleaning, inspection, assembly and machine shop practice are included. Always refer to appropriate engine overhaul article, if available, in the ENGINES section for complete overhaul procedures and specifications for the vehicle being repaired. Camshaft bearing replacement requires clean oil passages, correct bearing orientation, and accurate alignment with the block lubrication holes.
Removal & Installation
Remove camshaft rear plug. Camshaft bearing remover is assembled with shoulder resting against bearing to be removed according to manufacturer's instructions. Tighten puller nut until bearing is removed. Remove remaining bearings, leaving front and rear bearings until last. These bearings act as a guide for camshaft bearing remover. Work slowly and keep the tool centered so the bearing bore is not scratched or distorted. If the remover is allowed to cock in the bore, it can damage the block and make proper installation of the new bearing difficult.
To install new bearings, puller is rearranged to pull bearings toward the center of block. Ensure all lubrication passages of bearing are aligned with cylinder block. Coat new camshaft rear plug with sealant. Install camshaft rear plug. Ensure plug is even in cylinder block. Bearing oil holes must align correctly with the block passages; even a slight misalignment can restrict oil flow and lead to rapid camshaft or bearing failure. After installation, inspect every bearing bore visually and confirm that no burrs, chips, or sealer remain in the oil path.
New camshaft bearings should be installed squarely and to the correct depth. They must support the camshaft without tight spots, scraping, or uneven contact. Before final assembly on a Buick Enclave engine, test-fit the camshaft carefully if the procedure allows, and confirm that it rotates smoothly with proper lubrication.
CAMSHAFT INSTALLATION
NOTE: Examples used in this article are general in nature and do not necessarily relate to a specific engine or system. Illustrations and procedures have been chosen to guide mechanic through engine overhaul process. Descriptions of processes of cleaning, inspection, assembly and machine shop practice are included.
Always refer to appropriate engine overhaul article, if available, in the ENGINES section for complete overhaul procedures and specifications for the vehicle being repaired. Installation procedures may differ between in-block camshaft engines and overhead camshaft engines, so the correct bearing cap position, timing reference, and lubricant requirements must be followed.
Lubricate bearing surfaces and cam lobes with ample amount of Molykote or camshaft lubricant. Carefully install camshaft. Use care not to damage bearing journals during installation. Install thrust plate retaining bolts (if equipped). Tighten bolts to specification. On overhead camshafts, install bearing caps in original location. The camshaft must be supported while it is being slid into position so the lobes and journals do not scrape across the bearings. Avoid forcing the camshaft through the bearings; if resistance is felt, stop and inspect alignment, bearing condition, and lubrication.
On overhead camshaft designs, bearing caps are usually machined for a specific location and direction. They should be installed exactly where they were removed from, with all markings aligned. Tighten the cap bolts gradually and evenly to avoid bending the camshaft or damaging the cylinder head bearing surfaces.
Tighten bolts to specification. On all applications, check camshaft end play. After the camshaft is installed, rotate it by hand if the service procedure allows. It should turn smoothly without binding, scraping, or sudden tight spots. Any abnormal resistance should be corrected before the timing components, lifters, followers, or valve train parts are installed.
CAMSHAFT END PLAY
NOTE: Examples used in this article are general in nature and do not necessarily relate to a specific engine or system. Illustrations and procedures have been chosen to guide mechanic through engine overhaul process. Descriptions of processes of cleaning, inspection, assembly and machine shop practice are included.
Always refer to appropriate engine overhaul article, if available, in the ENGINES section for complete overhaul procedures and specifications for the vehicle being repaired. Camshaft end play affects timing stability, thrust surface wear, and valve train alignment, so the measurement must be checked before final assembly continues.
Using dial indicator, check camshaft end play. Position dial indicator on front of engine block or cylinder head. The dial indicator must be mounted securely, and the tip should contact a flat surface of the camshaft in line with its forward and rearward movement. A loose gauge mount or angled contact point can give an unreliable reading.
Position indicator tip against camshaft. Push camshaft toward rear of cylinder head or engine and adjust indicator to zero. Move the camshaft gently so the thrust surface is fully seated without damaging the camshaft, gear, plate, or cylinder head surface.
Move camshaft forward and note reading. Camshaft end play must be within specification. End play may be adjusted by relocating gear, shimming thrust plate or replacing thrust plate depending on each manufacturer. Too little end play can cause binding as the engine warms, while excessive end play can allow the camshaft to walk forward and backward, creating timing variation, noise, or thrust plate wear.
For Buick Enclave camshaft service, do not rely on visual alignment alone after installation. Measure end play, verify smooth rotation, confirm lubrication path alignment, and make sure all thrust-control components are installed exactly as required. These checks help prevent early valve train wear and protect the engine during the first start after overhaul.
