Solenoid Tech Tips By Dan Smith The following are some fast facts that we’ve picked up along the way and wanted to share. Hopefully there’s something here that might save you time or a warranty return. Delco 10-27MT Industrial Starters Using a heavy-duty 132-wind so- lenoid on all Delco 10-27MT indus- trial starters that have a large body drive will greatly improve the overall performance. The stronger coil will help to give positive drive engagement and ensure that the contacts are fully closed. Bosch Industrial Starters Bosch not only has three different types of moving contacts in the indus- trial “402” type solenoid, but also uses avariety of different plungers. Be sure to match the plunger style and length to the solenoid and to the starter ap- plication. Bosch Automotive Starters Bosch “303” type solenoids come in a standard and heavy-duty version. The heavy-duty type uses a thicker can wall and a smaller coil bobbin. Care must be taken to match coils to cans. A heavy-duty coil will fit into a stan- dard can, but because of the additional air gap, will not work properly. As with their industrial units, Bosch also uses different plungers for different starters. Overall length as well as the shift fork hole can vary. There are also different bolt patterns on some of these sole- noids. Bosch “302” type solenoids have a variety of plunger lengths and shift fork hole sizes. Hitachi Crimp cap Hitachi solenoids have numerous lengths of shift lever support springs. Be sure to match replacements to the OEM. 24V Hitachi solenoids used on in- dustrial applications will often have brass or steel plated studs. Industrial solenoids may have a flat bottom plunger rather than the typical concave type. They are not inter- changeable. Mitsubishi Mitsubishi automotive type sole- noids have many different stem lengths on the moving contact. The plunger used must be matched to the contact used. Industrial starters such as the Lester 17037 have two different length solenoids and they use different plung- ers. Be sure to match them. The package of spacer shims found with many Mitsubishi solenoids is not a packaging error. The shims are what are used to adjust pinion clear- ance. Nippondenso Some large Nippondenso starters use a shunt coil in the starter as part of the solenoid circuit. If this coil shorts, it will cause a malfunction of the sole- noid. Nippondenso gear reduction start- ers that have worn contacts should have the coils removed and inspected. When the contacts fail the starter will try to draw starting current through the switch terminal and coil wires. This is very common on industrial and late sil- ver body starters. Nikko/28MT There are two different versions of a four-terminal cap used on Nikko/ Delco 28MT. One is a normal “R” ter- minal, while the other is a dummy. MAY, 2000 Page 1 of 1