Chevrolet Citation/Omega/Phoenix/Skylark 1980-1985 Repair Guide

A Note About Terminology


There are a few descriptive words used in connection with the X-Body cars which may be new to you.

First, of course, is the term "X-Body" itself. The explanation for this, used to collectively describe the Citation, Omega, Phoenix, and Skylark, is quite simple. All General Motors cars have code names, used within the corporation to designate a body size series. For example, the full-size Impala, Eighty-Eight, LeSabre, and Bonneville are known within G.M. as "B-Bodies." The 1972 Nova was the first "X-Body," and all cars built on that floorpan since have been known by the term.

If this is your first front wheel drive car, you may not be familiar with the terms "transaxle," "halfshaft," or "constant velocity joint."

In a front wheel drive car, the transmission and differential share a common housing, and the front axles (halfshafts) are driven directly by this unit. Thus, a "transaxle" is a combination transmission/differential/drive axle. The X-Body cars use a manual transaxle as standard equipment and an automatic transaxle as an option.

"Halfshafts" are drive axles. The term came about as a way to describe the two shafts which emerge from the transaxle case and connect to the front wheels, transmitting power from one to the other. In a conventional front engine/rear drive car, a driveshaft is used to transmit power from the transmission to the drive axle. Thus, in a front wheel drive car, where there are two driveshafts, each one becomes half of a driveshaft, or a halfshaft. The halfshafts are also known as "drive axles."

A "constant velocity joint" is a variation on a conventional universal joint. Differences between them lie in the greater flexibility of the constant velocity joint, and its ability to transmit power at an angle without fluctuations in speed (thus, "constant velocity"). Two constant velocity joints are used on each halfshaft.

Because the X-Body is an all-metric car, there are a few metric terms with which you should be familiar, if only so that you won't become annoyed by the constant references to them in this guide. Newton-meters are the metric equivalent of foot-pounds, a measurement of torque. Thus, the "Nm."s you see in these pages are torque values in Newton-meters. Millimeters are abbreviated to "mm"; liters are "L". Celcius temperature measurements are of course abbreviated to "C." In all cases, conventional English equivalents are given in the text along with the metric value.