0309708 JOHNSON BEARING HEAD

Maintenance Intervals
The Maintenance Schedule requires all previous interval maintenance items to be performed first. For instance, if the Every 250 Hour maintenance is being done, then the Daily and Every 250 Hour maintenance items must be completed BEFORE performing the Every 1000 Hour maintenance.Engines may be equipped with various optional components and the Schedule may recommend maintenance for items not installed on your engine. Simply disregard reference to any extraneous items. If unsure of any item, consult your Caterpillar dealer.Overhaul Interval
One interval for some engines is labeled TOP END because it involves removal, inspection, and rework of the cylinder head components. This interval is dependent on load-sensitive items/total amount of fuel consumed. The last interval in each chart lists the components inspected, rebuilt, exchanged or replaced at overhaul. OVERHAUL is defined as the interval at which the major wear items in the engine should be replaced. The intervals represent maintenance of a non-failed engine. In other words, the engine is being rebuilt with certain new parts replacing worn parts such as piston rings, engine rod and main bearings, valves and valve seats., etc. Incidental to the replacement of these relatively few parts is the complete inspection of all other parts that are visible during the overhaul of the engine. The disassembly required to do an overhaul means that disturbed seals and gaskets, etc., will be replaced, and the internal passages of the engine and block be cleaned.* The OVERHAUL interval assumes that regular maintenance recommendations in the rest of the chart have been carefully followed.* Some users may obtain significantly longer or shorter life than the chart recommends between overhauls, but if the recommended intervals are followed, OVERHAULS will occur BEFORE actual FAILURE, and the total COST of operation will be minimized.Although most users will obtain more life between overhauls than the chart recommends, Caterpillar has determined that these limits are the best (least cost) for the vast majority of our engine users. Extend the intervals to overhaul ONLY if your experience shows strong evidence that the intervals are too short for your application and maintenance practices.The most important criteria for TOP END and OVERHAUL is Fuel Consumption. The hours criteria is mainly for reference.Interval Terminology
Engine components can generally be grouped into speed sensitive and load sensitive categories. Therefore, the maintenance interval for each item listed in the Maintenance Schedule is primarily based on the item and its relationship to either engine speed or load. Speed sensitive items such as water pumps, alternators, air compressors, etc., are not primarily affected by the load on your engine during operation. The load on an engine will not significantly accelerate the repair or replacement cycle for speed sensitive items. Therefore, the maintenance intervals established for speed sensitive items are based on calendar time and service hours. Load sensitive items such as piston rings, cylinder liners, bearings, etc., are affected by the load on your engine during operation. Generally speaking, the lower the load, the longer the engine life and conversely, the higher the load, the shorter the engine life. A heavy load on an engine will accelerate the repair or replacement cycle for load sensitive items. Load sensitive items are normally internal engine components. The amount of fuel consumed is directly related to the load on your engine. The amount of fuel consumed is a better indicator of when to perform maintenance than time, however Caterpillar recognizes that fuel consumption is difficult to document in some applications. An estimated fuel consumption figure can be used to determine some intervals.Maintenance Options
Rebuild with New Parts - Genuine Caterpillar parts are constantly tested and modified to incorporate the latest design advancements. Your Caterpillar dealer can rebuilt or provide the parts needed for overhauling your engine. Your benefit; long lasting replacement parts at competitive prices. New Components - Replace worn or failing components with new components. Repair Kits - These useful kits can be obtained from your Caterpillar dealer. These kits include all the necessary parts and instructions to repair the components in either the owner's maintenance shop or at a Caterpillar servicing dealer's facility. Repair kits simplify parts ordering, help speed repairs and reduce parts cost. Exchange - This cost-cutting service permits you to exchange worn engine components for quality Caterpillar Remanufactured or Caterpillar dealer rebuilt components on an over-the-counter basis. When you need them, these parts are ready for a substantial savings in both time and money. If there is a component you need, contact your Caterpillar dealer to see if it is offered under his Dealer Exchange Component Program. Caterpillar Factory Remanufactured Components - The latest remanufacturing techniques and procedures are used to restore components to Caterpillar's original functional specifications. Usually Caterpillar Remanufactured Components have a warranty identical to that of a new part. Remanufactured parts may not be available in your area. If there is a component you need, contact your Caterpillar dealer to see if it is offered under his Dealer Exchange Component Program. Contact your Caterpillar dealer for information. To minimize downtime, Caterpillar recommends that the use of Remanufactured components (subject to availability) is the most cost effective option. Before deciding which method is best, make sure all of the options and costs associated with repair have been considered. Some considerations are:* The costs associated with using separate parts from inventory versus the cost of a repair kit.* Downtime costs while the product is being rebuilt or repaired.* Total parts and labor costs for repairs versus the actual Remanufactured cost.* Remanufactured components from Caterpillar (if available) are covered by a standard, factory warranty.The following is a list of (R) Remanufactured components currently being offered by Caterpillar* in many countries:* Cylinder head - bare* Cylinder head - assembly and group* Crankshaft - undersized* Crankshaft - upgrade to new* Complete turbocharger* Turbocharger cartridges* Water pumps* Oil pump* Connecting rods* Air Compressor* Alternator* Electric starting motor If the component you need is not listed here, contact your Caterpillar dealer to see if it is offered under