1988 FIRENZA AND CUTLASS CALAIS MODELS AND 1988 CUTLASS SUPREME MODELS
Beginning with the following VIN breakpoints, 1988 Firenza and Cutlass Calais models 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 Cutlass Supreme models are equipped with a cast iron 'Top Hat' design steering gear assemblies from start of production.
Firenza
Leeds Assembly Plant (VIN Code K)
Ratio Bi-Letter VIN Breakpoints ----- --------- --------------- 16:1 cp JK308623 14:1 mw JK308724
Cutlass Calais
Lansing Assembly Plant (VIN Code M)
16:1 cp JM247851 14:1 wx JM248596
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.
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 'N W/SPORT SUSP (FE3), W/CAST IRON VLV HSG".
Additional bulletins regarding the image of cast iron top hat steering gear assemblies in Cutlass Ciera, Delta 88, Ninety-Eight and Toronado models 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.