Some 1986 Delta 88 models may exhibit a rear suspension banging noise noticeable on rough roads. This noise can result from the rear spring upper coils contacting each other on compression.
To correct this condition, replace the rear springs. If the vehicle has optional F41 or FE3 suspension, replace the springs with the comparable 1987 replacement spring. Refer to Spring Chart below for replacement spring application.
1986 Original Spring 1987 Replacement
Code Load Part Number Code Load Part Number ---- ---- ----------- ---- ---- ----------- Base Suspension 43.0 N/MM Rate
NYS 3480 10035259
NYT 3720 10035260
NYU 3960 25523979 SAME
NYW 4200 25523980
Base Suspension with G67 33.0 N/MM Rate
NTZ 3010 10027114
NUA 3190 10027115
NUB 3370 10027116 SAME
NUC 3550 10027117
F41 - FE3 Suspension 47.0 N/MM Rate
MBG 3260 25526961 SAME
NZB 3520 25524840 RRL 3432 25530359
NZC 3780 25524841 RRN 3900 25530361
NZD 4040 25524842 RRN 3900 25530361
NZE 4300 25524843 RRR 4368 25530363
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.