DETROIT DIESEL 53
the housing as shown in Fig. 14. Take measurements across
the entire length of each rotor lobe to be certain that a
minimum clearance of .004 " exists at the air outlet side of all
blowers and a minimum clearance of .0075 " (in-line engine
blower) exists at the air inlet side of the blower (Fig. 15).
b. Measure the clearance between the rotor lobes, across the
length of the lobes, in a similar manner. By rotating the
gears, position the lobes so that they are at their closest
relative position (Fig. 15). The clearance between the lobes
should be a minimum of .010 ".
Fig. 17 - Inserting Cam in Blower Drive
c. Measure the clearance between the end of the rotor and the blower end plate as shown in Fig. 16. Refer to the
chart for the required minimum clearances.
NOTE: Push and hold the rotor toward the end plate at which the clearance is being measured. After timing the rotors,
complete assembly -of the blower.
14. Remove the bolts and washers used to temporarily secure the front end plate to the housing. Then install the front
end plate to the blower with six bolts and special washers and two reinforcement plates and tighten the bolts to 20-25 lb-ft
BLOWER ROTOR END CLEARANCES
Engine Front End Plate Rear End Plate
15. Assemble the blower drive spring support as follows:
Place the drive spring support on two blocks of wood (Fig. 17).
Position the drive spring seats in the support.
Apply grease to the springs to hold the leaves together, then slide the two spring packs (15 leaves per pack) in
Place the blower drive cam over the end of tool J 5209, insert the tool between the spring packs and press the
cam in place.
16. Install the drive spring support coupling on the rotor gear at the rear end of the blower.
17. Secure the cam retainer to the coupling with four 1/4"-28 bolts and tighten them to 14-18 lb-ft torque.