Pontiac 19256448 Bearing Kit,Connect Rod

When overhauling an engine, it is standard practice to replace the main and connecting rod bearings with new ones, but it is useful to retain the old bearings, as these will reveal much about the condition of the engine. Some of the causes of bearing failure include inadequate lubrication, the presence of dirt or foreign particles, overloading the engine and corrosion, all of which have to be eliminated before re-fixing the engine for the same not to recur again. While inspecting the bearings they should be taken out of the engine parts and arranged in the same position on a flat surface so that in case of any flaw it may be matched with the crank shaft journal. Particles from other sources can be introduced in the engine during assembly time or through the filters, the PCV system, or can be residual chips or abrasives from a previous machining or reconditioning. The former may get lodged within the bearing material, while the latter score or gouge the bearing surface. To avoid such failures the interior as well as the exterior part of the car should be well cleaned and the oil and filter should be changed. Crushing of bearing due to lack of lubrication is normally due to heat stress, overloading, oil leaking or blocked oil ways and results in the bearing material being wiped fully off its backing. Some driving practices also affect bearing life in a vehicle; for example very low speed with a full throttle puts a lot of load which forces out the oil in the bearings while short journeys may cause corrosion owing to low heat generation. Also, incorrect bearing fitment leads to lasting oil starvation, or high spots that lead to failure sometimes.

In most cases when the engine is overhauled one is required to remove the main & connecting rod bearings then replace them with fresh ones while the removed bearings act as a bench reference on the status of the engine. Failure of bearings mainly results from lack of lubrication, presence of dirt or other particles, overloading of engine, and rusting hence corrections must be done before assembly to avoid the same. While inspecting the bearings they should be withdrawn from the particular place or area and arranged on the clean surface so that they can be match-marked or compared to the crankshaft journal. Contaminants can be brought into the engine during assembly, thru filters, or from machining operations and become lodged in the bearing material and cause scoring or gouging. To avoid this, all parts should be cleansed properly, and the oil and filter changed as often as should be. Lubrication can fail by burn-off, over; loading, leakage of oil, or plugging of the oil passages, and consequent severe damage may include the bearing material being extruded from its backing. There are also driving habits, which have considerable effect on bearings; for example, luging the engine will cause high loads and short trip causes corrosion. Further, improper bearing installation also shorten the life of the bearing as they can cause proper oil starved or, high spots that leads to failure.

With the pistons complete with piston rings and connecting rods, they can be installed in the engine. Ensure the cylinder bores are perfectly clean by wiping the cylinder walls several times with light engine oil and a clean, lint-free cloth. Lubricate the connecting rod bearings and install them into their appropriate rod and rod cap, ensuring the tang on the bearing fits into the notch in the rod or cap. Lightly coat the pistons, rings, and cylinder walls with light engine oil. To prevent the threaded bolts from possibly damaging the cylinder wall or crankshaft journal as the piston/rod assembly is pushed into place, install a length of rubber or plastic tubing over the connecting rod studs on one rod assembly. Check that all the piston ring gaps are positioned properly. Verify that the piston/rod assembly is correctly positioned, with most pistons marked with an 'F' or a drilled-out area indicating the front of the engine, and ensure the rod bearing tang slots are towards the outside of the engine block once installed. Place a piston ring compressor around the piston, with the base of the compressor about 1/4 inch above the bottom of the piston skirt, and tighten it until the rings are flush with the piston surface; gently cap the outside of the compressor to ensure the rings are fully compressed. Push the piston assembly into the bore, using a wooden hammer handle to tap the top of the piston slightly, and hold the ring compressor solidly against the cylinder block until all rings are inside the bore, continuing to push until the connecting rod is near its installed position. Ensure that all bearing surfaces and the crankshaft journal are coated with engine oil, then remove the tubing protector pieces and install the connecting rod bearing cap (with bearing) to the connecting rod. Torque the nuts to specification and repeat this procedure for all cylinders, using the rubber or plastic tubing on each assembly to prevent damage as the pistons are pushed into place, rotating the crankshaft as necessary to make the connecting rod nuts accessible for tightening.

When an engine is being overhauled, the main and connecting rod bearings should be replaced with new ones. Nevertheless, the old bearings must be kept for examination because they can tell a lot about the condition of the engine. Bearing failure may arise due to various causes including absence of lubrication, presence of dirt or foreign particles, overloading of the engine and corrosion. Regardless of the cause, avoiding future bearing failures requires that one rectifies the current failure before reassembling the engine. In referencing to any issues that may exist in relation to a corresponding crankshaft journal, these bearings should be taken from the engine block and main bearing caps as well as from connecting rods and rod caps and arranged on a clean surface in their original positions. Foreign material and dirt can enter into engines through improper assembly; passing by filters/PCV system or even present in oil. These particles sink into soft bearing material causing damage to it. This type of bearing failure can be prevented by regular cleaning of engine components and frequent oil and filter changes. Insufficient lubrication results from excessive heat; overloading; oil leakage or throw off; blocked oil passages etc. Such wiping leads to overheating when there is not enough lubrication whereby bearing material is wiped or extruded out from steel backing plates. Driving habits such as full throttle open throttle operation, short trip driving at low speeds in high gears also affect bearing life. Due to such habits we can experience high loads on bearings, which cause flexing, fatigue failure/corrosion. Poorly installed bearings during engine assembly like tight fitted bearings or trapped dirt/foreign particles have also been known to cause failures.

When working with Plastigage, three precautions should be taken, Before testing, make sure that all the oil and grease have been removed from the crankshaft and bearing surfaces, do not rotate the crankshaft whilst it has the Plastigage in position, and, when removing the Plastigage after the testing process, be very careful not to harm the crankshaft or the bearing surfaces; this can be done via wiping off the Plastigage with a fingernail or a blunt wood stick rather All major and big-end bearings should be checked for clearance when an engine is being overhauled, a procedure which applies whether new or reconditioned bearings are being fitted. First, it is advisable to fit in the main bearings and caps into the engine block after which you have to clean the crankshaft and the bearing portions with oil, grime, and other interferences. Take a strip of Plastigage and fit it along the extent of each of the main bearing journals, then fasten and snug each of the main bearing caps into position in accordance with the torque specifications and in such a way that the arrow on the cap points towards the front part of the engine. Following this tighten all bearing caps and then withdraw them with a view of measuring the flattened width of the Plastigage strip using the scale present on the Plastigage envelope to determine the bearing clearance. To find out if the cylinder bores are out of round, unbolt the Plastigage gently, turn the crankshaft 90 deg and then measure the clearances again using Plastigage the values with the first measurements to gauge for eccentricity. For connecting rod bearing clearance, assembled each piston/rod assembly as well as using the Plastigage as mentioned earlier and also for connecting rod side clearance. If the bearings are within tolerances they may be installed as described above, if not they must be replaced by correct size bearings and where upper and lower bearings are affected they must be replaced together.

When an engine is being overhauled, the main and connecting rod bearings should be replaced with new ones. Nevertheless, the old bearings must be kept for examination because they can tell a lot about the condition of the engine. Bearing failure may arise due to various causes including absence of lubrication, presence of dirt or foreign particles, overloading of the engine and corrosion. Regardless of the cause, avoiding future bearing failures requires that one rectifies the current failure before reassembling the engine. In referencing to any issues that may exist in relation to a corresponding crankshaft journal, these bearings should be taken from the engine block and main bearing caps as well as from connecting rods and rod caps and arranged on a clean surface in their original positions. Foreign material and dirt can enter into engines through improper assembly; passing by filters/PCV system or even present in oil. These particles sink into soft bearing material causing damage to it. This type of bearing failure can be prevented by regular cleaning of engine components and frequent oil and filter changes. Insufficient lubrication results from excessive heat; overloading; oil leakage or throw off; blocked oil passages etc. Such wiping leads to overheating when there is not enough lubrication whereby bearing material is wiped or extruded out from steel backing plates. Driving habits such as full throttle open throttle operation, short trip driving at low speeds in high gears also affect bearing life. Due to such habits we can experience high loads on bearings, which cause flexing, fatigue failure/corrosion. Poorly installed bearings during engine assembly like tight fitted bearings or trapped dirt/foreign particles have also been known to cause failures.

In most cases when the engine is overhauled one is required to remove the main & connecting rod bearings then replace them with fresh ones while the removed bearings act as a bench reference on the status of the engine. Failure of bearings mainly results from lack of lubrication, presence of dirt or other particles, overloading of engine, and rusting hence corrections must be done before assembly to avoid the same. While inspecting the bearings they should be withdrawn from the particular place or area and arranged on the clean surface so that they can be match-marked or compared to the crankshaft journal. Contaminants can be brought into the engine during assembly, thru filters, or from machining operations and become lodged in the bearing material and cause scoring or gouging. To avoid this, all parts should be cleansed properly, and the oil and filter changed as often as should be. Lubrication can fail by burn-off, over; loading, leakage of oil, or plugging of the oil passages, and consequent severe damage may include the bearing material being extruded from its backing. There are also driving habits, which have considerable effect on bearings; for example, luging the engine will cause high loads and short trip causes corrosion. Further, improper bearing installation also shorten the life of the bearing as they can cause proper oil starved or, high spots that leads to failure.

In most cases when the engine is overhauled one is required to remove the main & connecting rod bearings then replace them with fresh ones while the removed bearings act as a bench reference on the status of the engine. Failure of bearings mainly results from lack of lubrication, presence of dirt or other particles, overloading of engine, and rusting hence corrections must be done before assembly to avoid the same. While inspecting the bearings they should be withdrawn from the particular place or area and arranged on the clean surface so that they can be match-marked or compared to the crankshaft journal. Contaminants can be brought into the engine during assembly, thru filters, or from machining operations and become lodged in the bearing material and cause scoring or gouging. To avoid this, all parts should be cleansed properly, and the oil and filter changed as often as should be. Lubrication can fail by burn-off, over; loading, leakage of oil, or plugging of the oil passages, and consequent severe damage may include the bearing material being extruded from its backing. There are also driving habits, which have considerable effect on bearings; for example, luging the engine will cause high loads and short trip causes corrosion. Further, improper bearing installation also shorten the life of the bearing as they can cause proper oil starved or, high spots that leads to failure.

In most cases when the engine is overhauled one is required to remove the main & connecting rod bearings then replace them with fresh ones while the removed bearings act as a bench reference on the status of the engine. Failure of bearings mainly results from lack of lubrication, presence of dirt or other particles, overloading of engine, and rusting hence corrections must be done before assembly to avoid the same. While inspecting the bearings they should be withdrawn from the particular place or area and arranged on the clean surface so that they can be match-marked or compared to the crankshaft journal. Contaminants can be brought into the engine during assembly, thru filters, or from machining operations and become lodged in the bearing material and cause scoring or gouging. To avoid this, all parts should be cleansed properly, and the oil and filter changed as often as should be. Lubrication can fail by burn-off, over; loading, leakage of oil, or plugging of the oil passages, and consequent severe damage may include the bearing material being extruded from its backing. There are also driving habits, which have considerable effect on bearings; for example, luging the engine will cause high loads and short trip causes corrosion. Further, improper bearing installation also shorten the life of the bearing as they can cause proper oil starved or, high spots that leads to failure.