How To Repair Solenoids for Ford PMGR, Delco PMGR and Delco $D210/260 Starters WAI Technical Update 25 COLUMN BY JOE DAVIS In this update I would like to review the repair of domes- tic crimp-type sole- noids—solenoids that have the sole- noid body crimped over the cap to hold the solenoid together. Although crimp-type sole- noids have been around for some time on import starters, they are only recently being used on domestic units—specifically Ford PMGR (per- manent magnet gear reduction), Delco PMGR and Delco $D210/260 series. In the procedures below we used a crimp-cap tool as an aid in opening and closing the solenoids. Ford PMGR Solenoids Repairing the solenoids for Ford units is fairly straightforward, as long as you take a few precautions. Here is the best way we have found to proceed. Opening the Solenoid 1. Secure the solenoid to a base plate. 2. Scribe a mark in the solenoid body to indicate the position of the switch terminal. 3. Place the base plate, with the sole- noid mounted, in a press. 4. Select a round press bar with an open end that fits over the plastic part of the solenoid plunger. CAUTION: Pressing on the plastic tip of the plunger will destroy it! (See Figure 1.) 5. Insert the press bar onto the sole- noid plunger and press through the solenoid. This will open the crimp and push the cap and solenoid assembly out of the solenoid body. 6. Service or replace the solenoid cap and coil as necessary. Note that some Ford solenoids have a diode molded into the cap that is connected in parallel to the hold-in windings. (See Figures 2 and 3). This diode clamps the induced voltage that is created in the windings when the solenoid is deactivated. To test for the presence of this diode while the solenoid is assembled, use a digital-reading diode tester that meas- ures forward voltage drop. Connect one test lead to the switch terminal and the other test lead to ground and note the reading. Reverse the positions of the test leads and note the reading again. If the readings are the same, the diode is not operational. This may be due to a poor ground, a bad diode, or the absence of a diode. On the tester we used, the readings were .792 and .747. In all cases you can install a solenoid with a diode in place of a solenoid with- out a diode to provide the ability to clamp spike voltage. Closing the Solenoid First, you will probably want to enlarge the crimp area of the solenoid to make installation of the coil and cap easier. To do this try putting a trailer- hitch ball against the crimp area and giving it a bump with a hammer. Then proceed as follows. 1. Align the switch terminal with the scribe mark on the solenoid body and install the coil assembly and cap. Make sure you have two wires at the switch terminal. 2. Place light pressure on the sole- noid cap and peen over the crimp in two places 180 degrees apart. This keeps the cap in place during the crimping operation. 3. Place the solenoid base plate onto the press and place the crimping die over the solenoid. Place the cover over the crimping die and press the assembly. 4. Turn the crimping die over and press the crimp again. This will flatten out and seal the crimp. 5. Solder the two wires at the switch terminal and the one wire at the motor terminal. 6. Test the solenoid. Delco Solenoids Delco solenoids, on the other hand, are a more challenging project than Ford for several reasons. First, there are no threaded holes for attaching the base plate. Second, the plunger sleeve is flared outward, so the flared end must be removed before the solenoid will come apart. (See Figure 4.) Third, later style solenoids have RTV_ sealant sealing the coil at the plunger opening. Finally, keep in mind that early solenoids have a round contact disk, whereas later ones have a rectangular contact disk. Here is how to deal with the quirks of these solenoids. Opening the Solenoid 1. Cut off the crimped/welded part of the switch and motor terminals. Grind the tip of these terminals to open the hole and release the wires. 2. Using a lathe, cut off the flared end of the plunger sleeve. (See Figure 4.) 3. Secure the solenoid to a base plate. The plate we use has three screws posi- tioned 120 degrees apart, to match the three recesses in the sole-noid body. However, these recesses may not exist on some SD210/260 series solenoids. In this case, tighten the three screws into the solenoid body until they dimple the body to a depth of approx- imately .030″ to .050.” Make sure you keep the solenoid square with the base plate or it may cause binding during the pressing operation. 4. Scribe a mark in the solenoid body to indicate the position of the switch terminal. 5. Place the base plate, with the solenoid mounted, in a press. 6. Select a round press bar that fits into the solenoid plunger opening and press until the solenoid cap comes out of the body approximately .115.” OE sole- noids have a ridge in four places around the lip of the cap that can be used to gauge this distance