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HOMESERVICE MANUALSFORD1987ECONOLINE E350, VAN DISPLAY EXTENDED, 6.9 1REPAIR AND DIAGNOSIS (SINGLE PAGE)DRIVELINES & AXLESDRIVESHAFT & UNIVERSAL JOINTSDRIVE SHAFT ALIGNMENTADJUSTMENTSFLANGE ALIGNMENT & RUNOUT

1987 Ford Econoline E350, Van Display Extended, 6.9 1

Flange Alignment & RUNOUT

1987 Ford Econoline E350, Van Display Extended, 6.9 1SECTION Flange Alignment & RUNOUT

All flanges must be perpendicular in both vertical and horizontal planes to engine crankshaft. Only exception is "broken back" type driveline, which has flanges that are not perpendicular in vertical plane. See Fig 1 .

Fig 1: Typical "Broken Back" Type Drive Shaft Alignment Angle "A" equals angle "B".
With nonparallel or "broken back" type installation, working angles of universal joints of given drive shaft are equal. 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.
Parallel type joints maintain constant velocity between output shaft and pinion shaft. Vibration is minimized and component life maximized when universal joints are parallel.

Fig 2: Aligning One-Piece Drive Shaft Yokes must be parallel.
Using dial indicator, measure runout of transmission flange, center bearing flange and pinion flange. If runout exceeds .003-.005" (.08-.13 mm), replace flange.
If dial indicator cannot be used, push rod with slip fit through flange bearing bore. See if it aligns with opposite bore. If not, replace flange.
Rotate transmission flange until it is vertical, measuring from side. Check center bearing and pinion flanges. They cannot be more than one degree off vertical. See DRIVE SHAFT PHASING in this article.

Fig 3: Vertical Alignment of Drive Shaft Flanges in pairs should be parallel.
Rotate transmission flange until it is vertical, measured from side. Measure angle from end and record it. Check all other flanges for same angle. They must be within 1/2 degree of each other. Adjust as required.
If difficulty is encountered when making above adjustments, horizontal alignment should be checked. Even though vertical alignment is correct, horizontal alignment can be badly out of adjustment. This is often found after major component replacement or repair of serious accident damage. See Fig 4 .

Fig 4: Horizontal Alignment of Drive Shaft Plane of trunnions should be parallel.
To make horizontal alignment checks, set straightedges up. See Fig 5 . Set transmission output flange horizontal and clamp straightedge to flange in a horizontal plane. Repeat procedure with drive pinion flange. Ensure that flanges are horizontal by checking angle of straightedge with spirit level.

Fig 5: Checking Horizontal Alignment Measure at 6 points shown using straightedges and framing squares.
Using straightedge that is 12" longer than width of rear wheel track at 90 degrees, clamp to frame side rails. Use large framing squares to align straightedge with side rails.
Measure distance "X" at each side. If both measurements are not within 1/16" (1.6 mm) of each other, transmission flange is horizontally misaligned.
Measure distance "Y" (edge of straightedge to axle shaft centerline) at each side. If 2 dimensions are not within 1/8" (3.2 mm) of each other, axle housing is misaligned.
Measure distance "W" at each side. If both measurements are not within 1/16" (1.6 mm) of each other, pinion flange is horizontally misaligned.