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HOMESERVICE MANUALSGMC1981VANDURA SPECIAL AUTOMATIC TRANS, TRANS MFR CD 400/M40REPAIR AND DIAGNOSIS (SINGLE PAGE)DRIVELINES & AXLESDRIVESHAFT & UNIVERSAL JOINTSPROPELLER SHAFT ALIGNMENTADJUSTMENTSFLANGE ALIGNMENT & RUNOUT
1981 GMC Vandura Special Automatic Trans, Trans Mfr CD 400/M40

Flange Alignment & Runout

1981 GMC Vandura Special Automatic Trans, Trans Mfr CD 400/M40SECTION Flange Alignment & Runout
  1. All flanges must be perpendicular in both vertical and horizontal planes to engine crankshaft. The only exception is "broken back" type driveline which has flanges that are not perpendicular in vertical plane. See Fig. 5. 
  2. With nonparallel or "broken back" type installation, working angles of universal joints of a given drive shaft are equal. See Fig. 7.  Angle A = Angle B. This is calculated as follows: Angle of output shaft centerline is subtracted from angle of drive shaft. Difference should equal angle of drive shaft subtracted from pinion shaft angle.
  3. Parallel type joints maintain a constant velocity between output shaft and pinion shaft. Vibration is minimized and component life maximized when universal joints are parallel.
  4. Using dial indicator, measure runout of transmission flange, center bearing flange, and pinion flange. If runout exceeds 0.003 - 0.005", replace flange. If dial indicator cannot be used, push a rod with a slip fit through flange bearing bore and see if it aligns with opposite bore. If not, replace flange.
  5. Rotate transmission flange until it is vertical, measuring from side. Check center bearing and pinion flanges; they cannot be more than 1° off vertical.
    NOTE: See Propeller Shaft Phasing in this Section.
RENDER: 1.0x

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