NEW 120 AMP GENERATOR TENSIONER ASSEMBLY
VEHICLES AFFECTED: 1985 FWD DeVilles and Fleetwoods --------------------------------
All Front Wheel Drive Fleetwoods and DeVilles built after VIN breakpoint 321327 are equipped with a 120 amp 17 SI generator, a new rear generator bracket, serpentine belt and belt tensioner assembly. Vehicles built at or before VIN breakpoint 321327 are equipped with a 108 amp 17 SI generator. Vehicles equipped with the 120 amp generator can be identified by a VIN breakpoint greater than 321327 and the 120 amp specification and P/N 1105656 marked on the end of the generator drive end frame (see Figure 1).
IMPORTANT: Due to a larger pulley size and different rear generator mounting bracket configuration, the 120 amp 17 SI generator, new rear generator mounting bracket, serpentine belt and belt tensioner assembly are not interchangeable with respective components on vehicles with the 108 amp 17 SI generator built at or before VIN breakpoint 321327.
The new 120 amp generator uses a split tapered collar to retain the generator pulley. The collar is not removable. Therefore, to service any drive end frame components, it is necessary to replace all of the drive end frame components as an assembly using service kit P/N 10495628 which contains the parts listed below.
1. Drive End Frame 2. Rotor 3. Fan (with baffle) 4. Pulley 5. Sealed Front Bearing 6. Bearing Retainer Plate and Screws 7. Split Tapered Collar 8. Spacers 9. Lock Washer 10. Nut
The remaining generator components can be serviced using the following part numbers:
NAME P/N ---- --- Complete 120 amp Generator Assembly 1105656 Slip Ring End Frame 1989517 Slip Ring End Frame Bearing 9436831 Stator 1988989 Rectifier Bridge 1988976 Rectifier Bridge Hold Down Screws 1988971 Diode Trio 1988985 Brushes and Brush Holder 1989719 Capacitor 1988972 Capacitor Hold Down Screws 1988970 Voltage Regulator 1988988
The following are additional changes made on vehicles equipped with the 120 amp generator:
1. Serpentine Belt - The new serpentine belt (P/N 1625690) used with the 120 amp generator is slightly longer than the previous belt. This new belt may not be used on vehicles built at or before the 321327 breakpoint.
2. Tensioner Assembly - The new tensioner assembly (P/N 1636207) places 10 lbs. (44.5N) less tension on the serpentine belt. This new tensioner may not be used on vehicles built at or before the 321327 breakpoint.
3. Rear Generator Mounting Bracket - The rear mounting bracket (P/N 1631200) used with the 120 amp generator has the rear mounting bolt located 5mm closer to the generator hub centerline.
IMPORTANT: None of the above part numbers can be used on vehicles equipped with a 108 amp, 17 SI generator, built before the 321328 breakpoint.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
