OPERATION OF MEDIUM WRECKER (Contd)
For lift-tow operations (except M936A2):
Attach whiffletree (3) to lifting shackles (4) of disabled vehicle. Whiffletree (3) is attached the same way
as a towbar (12). Refer to step 4c.
Lower crane block (2) and insert hook (5) through center hole of whiffletree (3). Refer to crane operation
Remove two retaining pins (11) and towbar adjustment pins (10). Slide out leg extensions (9).
Attach two clamps (8) to clevis (13) of leg extensions (9) and secure in place with clevis bolts (14) and
attached safety pins (15).
Loosen two tension adjusting nuts (7) on clamps (8).
Position clamps (8) against front axle (16) of disabled vehicle and wrap clamp chain (6) around axle and
back up through clamp (8). Lock in place by turning tension adjusting nut (7) until secure.
Repeat step f with second clamp (8) in position against axle (16) on opposite side of forward axle.
If necessary, adjust length of towbar while performing step h. Yoke end of towbar should extend one foot
or more beyond front bumper of disabled vehicle.
After both clamps (8) are secured to disabled vehicle, slide leg extensions (9) back into towbar (12) and
secure in place with adjustment pins (10) and retaining pins (11).
Install yoke end of towbar (12) on wrecker pintle hook (16).
Disengage brakes and remove propeller shafts between transmission and transfer and place transfer in
high range of disabled M939/A1/A2.
Raise crane block (2) and lift front wheels of disabled vehicle off ground until towbar is level (parallel to
To secure from lift-tow operation, reverse steps a through k