ELECTRICAL REBUILDER’S ASSOCIATION—Technical Document $S201402B www.electricalrebuilders.org Rebuilding Prelub™ Starters It’s not rocket science BY BOB THOMAS AND WES GRUENINGER SR. relub™ Delco-Remy starters have been on the market since 1985, yet most rebuilders seldom ever see one. The idea of pressurizing an engine’s lubrication system prior to starting the engine was then, and still is, a good idea. The benefits are many, and when added up, far exceed the cost. Prelub™ is the registered trademark of RPM Industries, Inc, who manufactures the components and converts new Remy starters into Prelub™ starters in their Washington, PA factory. Since 1985, they have converted thousands of 40MT, 41MT, 42MT and 50MT starters. Prelub™ starters are easily identified by the gear pump on the commutator end housing. When a start switch for an engine with a Prelub™ starter is turned on, initially, the engine will not crank. Instead, the starter will motor to operate the gear pump, which then pressurizes the engine’s lubrication system. Once pressurized, an oil pressure switch allows the solenoid to engage the starter in a normal manner. Depending on the engine and the amount of oil required to pressurize any particular system, cranking may be delayed by a few seconds or up to 45 seconds, following an oil and filter change. Because they extend the longevity of the engines they have been installed on, most of the Prelub”™ starters sold are still in use today. Like all other starters, they will eventually need rebuilding or replacement. In an effort to save themselves time and save their customers money, some rebuilders are selling conventional starters to replace Prelub™ starters. If that’s you, then you are not doing your customers or yourself any favors. It’s a fact that most engine wear takes place at start-up, before the lubrication system is pressurized. This is especially a problem with either large diesel engines, where oil pressure delay times can be a lot longer than a few seconds—or with equipment that may have long time delays between starts—known as dry starts. Dry starts also occur following every oil change, when oil filters must be filled before system pressure can build. Use of Prelub™ starters has been proven to more than double the life of all wearing surfaces inside the engine, especially rod and main bearings. Engine overhauls on some of these engines can cost well into the tens of thousands of dollars. When averaged out over time, a Prelub™ starter pays for itself in less than a year—that is unless you talk your customer into replacing it with a conventional starter. Then, the value of making that up-front purchase of a Prelub™ starter, has been lost Figure 2—View of gear pump with cover removed. Figure 1—Prelub™ armature shaft and oil pump drive gear. Figure 3—View of the 6203 support bearing with oil seal below it. An ERA Publication. ©2014, Electrical Rebuilder’s Association. All rights reserved. No portion of the guide may be reproduced Page 1 in any way, or stored in any electronic retrieval system without the prior written consent of the Electrical Rebuilder’s Association. ELECTRICAL REBUILDER’S ASSOCIATION—Technical Document $S201402B www.electricalrebuilders.org PRELUB™ STARTER SYSTEM AS USED BY CATERPILLAR TO OPTIONAL SECOND-STARTER RELAY NEUTRAL SWITCH (OR COMPUTER) +2av — HH © oH PRELUB” TIMER/RELAY ASSEMBLY : STARTER +24V SOLENOID MAGNETIC }@¥ SWITCH PRELUB”” STARTER OIL PRESSURE SWITCH – NC ( How IT WORKS: | 1. The operator turns the key switch to the CRANK position and holds it. . The timer assembly sends power to the coil of the Prelub™ magnetic switch which closes and sends power to the starter motor terminal. . The starter now runs in pre-lube mode. The motor spins but the fly- wheel is not engaged. . The starter motor runs for 5 to 45 seconds until the oil pressure switch opens between 4 psi and 7 psi. . When the oil pressure switch opens, the timer assembly turns off the Pre- lub™ magnetic switch, which stops the starter motor. . The key switch is still held in the CRANK position. The timer assembly has a built in 3-second delay to allow the starter to stop spinning. . Then the timer sends power to the starter relay, the starter engages the flywheel and the engine is cranked normally. . After the Prelub™ system has been activated, the timer assembly will not allow activation again until the key switch has been in the OFF position for a least two minutes. ) An ERA Publication. ©2014, Electrical Rebuilder’s Association. All rights reserved. No portion of the guide may be reproduced in any way, or stored in any electronic retrieval system without the prior written consent of the Electrical Rebuilder’s Association. Page 2 ELECTRICAL REBUILDER’S ASSOCIATION—Technical Document $S201402B Figure 4—Side view of Prelub™ gear pump housing with cover, armature and brushes installed. forever. The original cost of the Prelub™ starter was $700 to $1,000 above the cost of a conventional starter—an investment that has already been made. It should be worth more to your customer to retain it when the starter does fail. What makes this starter different from a rebuilder’s point of view are only a few component parts. They are the armature shaft (see Figure 1) and a unique commutator end housing that contains a ball bearing, an oil seal and a gear pump (see Figures 2, 3 and 4). The remainder of the starter’s parts are the same as a conventional Remy starter. Does it cost you more to rebuild one of these? Unless a pump fails, the answer is no, not much. The bearing, a common 6203, and the pump’s oil seal are really the only additional wearing parts that you will need in most cases. The armature, if it requires replacing, is available, as are the pump’s gears. Since the Prelub™ starter is actually worth more to your customer, you can recover those added costs and still end up with more profit over a conventional starter. It is always relatively easy to talk a customer into spending less money. That is the path of least resistance, or in this case, the low road” But that is not the best road for your customer, and it is not the best road for you either. If you talk a customer into a cheaper starter, and it costs him an engine, even two or three years later, he may blame you for it. lam not suggesting that, should your customer insist on a standard starter, you should not sell it to him. I am explaining why you should make an attempt to sell your customer on rebuilding his Prelub™ starter, for the benefit of both of you. It is an easy sell if you just take the time. Thanks to Hank Henke, United Starter and Alternator of supplying the parts and information to make this possible. An ERA Publication. ©2014, Electrical Rebuilder’s Association. All rights reserved. No portion of the guide may be reproduced in any way, or stored in any electronic retrieval system without the prior written consent of the Electrical Rebuilder’s Association. www.electricalrebuilders.org