RACK AND PINION POWER STEERING GEAR
TRACK AND PINION POWER STEERING GEAR NEW CAST IRON TOP HAT (CITH) DESIGN
VEHICLES AFFECTED: 1988 MODEL YEAR "J" AND "N" CARS (ALL NAMEPLATES) ----------------- 1988 MODEL YEAR "W" CARS Beginning with the following VIN breakpoints, 1988 model "J" and "N" body vehicles equipped with power steering are utilizing a new type of center take-off power rack and pinion steering gear assembly. This new type gear assembly utilizes a cast iron 'top hat' in the upper portion of the valve housing assembly. It can be easily identified by visual observation of the housing assembly, or by checking for correct bi-letter codes stamped on the tie rod lock plate (refer to figure). All 1988 model year Cutlass Supremes are equipped with a cast iron 'top hat' design steering gear assemblies from start of production. Breakpoint Information ---------------------- "J" Body Vehicles Leeds Assembly Plant (Vin Code K) Bi-Letter Oldsmobile Buick Ratio Code VIN VIN ----- --------- ---------- ----- 16:1 CP JK308623 JK420707 14:1 MW JK308724 JK420909 Janesville Assembly Plant (VIN Code J)
Chevrolet Cadillac VIN VIN --------- -------- 16:1 CP JJ184475 14:1 MU JJ504243 14:1 MW JJ184451
Lordstown Assembly Plant (VIN Code 7)
Chevrolet Pontiac VIN VIN --------- -------
16:1 CP J7158411 J7540428 14:1 MW J7158403 J7540419
Lansing Assembly Plant (VIN Code C)
Pontiac VIN ------- 16:1 CP JC700907 14:1 WX JC700140
"N" Body Vehicles
Lansing Assembly Plant (VIN Code M)
Oldsmobile Buick VIN VIN ---------- -----
16:1 CP JM247851 JM027556 14:1 WX JM248596 JM08120
Service Part Number Information
When replacing a steering gear assembly, be sure to properly identify the type of rack assembly (Cast Iron Top Hat valve housing or Aluminum valve housing) in the vehicle. The GMSPO parts catalog will indicate the correct part number(s) to order based on the model, model year, and type of valve housing (Cast Iron or Aluminum) the vehicle steering gear is equipped with.
Notice: There is an error in the January 1988 issue of the Oldsmobile "N" Parts Catalog.
On the model reference page for 1988 Oldsmobile steering gears (Group 6.508):
The usage for part number 26008644 indicates "N w/Sport SUSP (FE3), w/ALUM VLV HSG". It should read as follows: "N w/SPORT SUSP (FE3), w/CAST Iron VLV HSG".
Additional Bulletins regarding the usage of Cast Iron Top Hat steering gear assemblies in A, C, H, and E body vehicles will be published as information becomes available.
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.
