Drive Shaft Alignment Buick Roadmaster VIII

BODY CODE IDENTIFICATION

BODY CODE IDENTIFICATION

Note. Camaro, Corvette and Firebird drive shaft alignment information not available at time of publication

DESCRIPTION & OPERATION

Drive shaft is used to transmit power from transmission to rear axle assembly. Use proper universal joint alignment angle to provide smooth operation of drive shaft. Check front and rear universal joint angles with vehicle at proper ride height and a full gas tank. Adjust front universal joint by shimming transmission mount. Adjust rear universal joint angle by shimming transmission mount, repositioning pinion nose or by replacing rear control arms.

Scheme 1

Scheme 2

Scheme 3

1. Ensure vehicle is at proper ride height with a full tank of gasoline. Measure axle tube-to-frame height (ride height) from top of axle tube to bottom of frame. (Scheme 1) Bounce vehicle and allow to return to normal ride height before measuring. Refer to the below «RIDE HEIGHT & UNIVERSAL JOINT ANGLE SPECIFICATIONS»(/buick/roadmaster/viii-1991-1996/remont/driveshaft-universal-joints/#drive-shaft-alignment) table.
2. If ride height is not within specification on models with electronic suspension, adjust height sensor. See «HEIGHT SENSOR»(/buick/roadmaster/viii-1991-1996/remont/driveshaft-universal-joints/#drive-shaft-alignment__height-sensor) under ADJUSTMENTS. On models without electronic suspension, add weight to trunk to obtain correct ride height.
3. With vehicle level, measure universal joint angles. Clean bearing caps. Install Inclinometer (J-23498-A ) on rear drive shaft bearing cap. (Scheme 2) Bearing cap must be vertically aligned (straight up and down). Center bubble in sight glass, and record reading.
4. Remove inclinometer, rotate drive shaft 90 degrees and install inclinometer on drive yoke bearing cap. Measure angle and subtract smaller reading from larger reading to determine rear universal joint angle.
5. Attach Inclinometer Adapter (J-23498-20 ) to front drive shaft bearing cap. (Scheme 3) Attach inclinometer to adapter and repeat procedure used on rear universal joint to obtain front universal joint angle.

HEIGHT SENSOR

Scheme 4

1. With link attached to metal arm, loosen metal arm-to-height sensor plastic arm lock bolt. (Scheme 4) To increase ride height, move plastic arm upward. To decrease ride height, move plastic arm downward. Tighten lock bolt.
2. For every one degree change in angle arm, the trim (riding) height will change by approximately 1/4" (6 mm). The arm angle may be changed at total of 5 degrees, approximately 1 1/4" (32 mm).

"B" & "D" Bodies

Adding one shim at transmission mount decreases front universal joint angle 1/2 degree, and increases rear angle 1/4 degree. Removing one shim from transmission mount increases front universal joint angle 1/2 degree, and decreases rear angle 1/4 degree.

Note. Production transmission mount bolt is M10-1.5 x 35 mm. When using 2 or more shims, a M10-1.5 x 50 mm bolt must be used.

Rear universal joint angle corrections +/-1 degree can be made by loosening all rear suspension control arm bolts. Reposition pinion nose up or down, and tighten all bolts.

By using different length control arms available for universal joint angle service, joint angle can be corrected. Rear joint angle can be corrected to within +/-2 degrees. Front joint angle can be corrected to within +/-1/3 degree.

RIDE HEIGHT & UNIVERSAL JOINT ANGLE SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• RIDE HEIGHT & UNIVERSAL JOINT ANGLE SPECIFICATIONS
• HEIGHT SENSOR