Town Car 1993

Serial Number Identification


Drive Axle

The rear axle assembly is an integral-type housing hypoid gear design with the centerline of the pinion set below the centerline of the ring gear.

The hypoid gearset consists of a 8.8 inch (224mm) diameter ring gear and an overhung drive pinion which is supported by two opposed tapered roller bearings. Pinion bearing preload is maintained by a collapsible spacer on the pinion shaft and adjusted by the pinion nut.

The housing assembly consists of a cast center section with integral cast suspension attaching ears, two steel tube assemblies, and a steel rear cover. The cover uses a silicone sealant rather than a gasket.

The differential case is a one-piece design with two openings to allow for assembly of internal components and lubricant flow. The differential pinion shaft is retained by a threaded bolt assembled to the case. The differential case assembly is mounted in the carrier between two opposed tapered roller bearings. The bearings are retained in the carrier by removable bearing caps.

Differential bearing preload and ring gear backlash is adjusted by shims located between the differential bearing cup/races and the carrier housing.

The use of a hypoid shim gauge in conjunction with a differential shim gauge is required for proper gearset adjustment.

The semi-floating axle shafts are held in the housing by C-washer locks positioned in a slot on the axle shaft splined end. These C-washers also fit into a machined recess in the differential side gears within the differential case.

The Plant Code on the axle identification tag is the official service identifier. The axle identification tag is located under the cover-to-carrier bolt in the 12 o'clock position. The Plant Code for a particular axle assembly will not be duplicated.


The engine identification code is located in the VIN at the 8th digit. The VIN can be found on the Vehicle Certification Label and on the VIN plate attached to the instrument panel. See the Engine Identification chart for engine VIN codes.

There is also an engine code information label located on the engine. This label contains the engine calibration number, engine build date and engine plant code. On the 3.8L and 5.0L engines, the label is located on the side of the right rocker arm cover. On the 4.6L engine, the label is located on the front of the engine.

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Fig. Sample engine code information label