Difference between revisions of "AB-1386~U"
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| + | ==No gearbox, or inoperable gearbox== | ||
| + | If the gearbox is missing, this tower can still be used. you simple remove the drive screw and manually extend the tower. You will need something to place between the last section to hold it up, or a pin to prevent it from collapsing. The process for removing the drive screw is detailed in the TM linked below. | ||
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| + | ==Section will not collapse== | ||
| + | The tower is designed so that the sections cannot collapse until the one below it is fully down, there is a small toggle inside the "lock" where the "post" unlocks the next section. If for some reason the "post" engages but does not unlock the next section, use a flat screwdriver to toggle the lock and the section will unlock. | ||
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==Frozen Bearing== | ==Frozen Bearing== | ||
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[[File:AB1386_GEARBOX_1280.JPG|thumb|right|Pressing new bearing onto the aluminum backing]] | [[File:AB1386_GEARBOX_1280.JPG|thumb|right|Pressing new bearing onto the aluminum backing]] | ||
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==Crank turns, but won't raise or lower the tower== | ==Crank turns, but won't raise or lower the tower== | ||
Revision as of 02:43, 27 September 2012
Contents
Description
AST AB-1386/U - NSN 5985-01-381-6341
Total mast height is variable from 8.3 to 33.1 ft (2.5 to 10.1 m) with all mast sections fully deployed. Accessories are provided to assist with guying, anchoring, and operating the mast in its ground mount configuration. They include a hammer, a tripod, guy assemblies, guy stakes, baseplate stakes, crank handle, baseplate, and a radius rope.
Two mounting kits may be used to adapt the HMMWV and the tracked vehicle with brackets and hardware to deploy the mast. The mounting kits are used to anchor the mast to the vehicle and to stabilize the mast when deploying it under normal conditions (i.e., winds below 25 mph [40 kph]).
Common problems
No gearbox, or inoperable gearbox
If the gearbox is missing, this tower can still be used. you simple remove the drive screw and manually extend the tower. You will need something to place between the last section to hold it up, or a pin to prevent it from collapsing. The process for removing the drive screw is detailed in the TM linked below.
Section will not collapse
The tower is designed so that the sections cannot collapse until the one below it is fully down, there is a small toggle inside the "lock" where the "post" unlocks the next section. If for some reason the "post" engages but does not unlock the next section, use a flat screwdriver to toggle the lock and the section will unlock.
Frozen Bearing
Upon removal there is a large bearing, I had to replace this, as mine was frozen up. the proper replacement bearing is a Koyo #62052RDC3. You will need a press to do this..
- Remove the bearing from the housing
- Lightly tap the bearing while holding the outer ring to remove it (the one with the notch)
- Place the bearing in the press or suitable jig, and knock the brass bushing out from the rear.
- Remove the aluminum backing is attached to the bearing in the center, this wasn't meant to be re-used, so you will have to cut the bearing from around it. I tried using different pullers, but the aluminum will bend and deform, before the bearing is removed.
- Once this is cut off you can press this into the new bearing and re-install it.
Crank turns, but won't raise or lower the tower
This is usually due to the output shaft notch no longer being tight. When the crank shaft is turned, this also turns inside the saft and wont turn the large screw on the tower.
To test this, put a screwdriver in the output shaft, and attempt to hold the shaft in place while turning the crank, if you can turn the crank, and the screwdriver doesn't turn, you have confirmed it.
I attempted to resolve this many ways,
- Dimpling the edge of the shart to make the notch tight
- JB Weld
- Wedging it by taping it fron the back
- Welding
Welding was the only one that worked. What you dont want, which i was privileged enough to experience, is to get the tower up, then have this loosen up again, and have no way to lower it. Weld it, you don't want this problem.. trust me.
Gear Box Images
All parts view
Stripped Gearbox
Main crank gear
Main crank gear closeup
Gearbox with crank gear installed
Closeup of output shaft
Side view of output shaft
Top view of output shaft
Output shaft, with gear installed
Output shaft and brake? disk installed
Output shaft and brake disk
Side view of output shaft, with gear and bearing installed
Truck Pictures
Fully deployed mast
Base in the bed pocket, with mast without gearbox
Side view of bottom support, without gearbox
View of upper attachment
View of bottom support without the mast
Mast fully stored for transport
Detail of rear storage bracket
Wide view of mast in storage
Detail of front storage bracket
Wide view front to read
View of mast on base, with gearbox
Mast upright, with gearbox and new upper clamp
Additional Files
- OPERATOR'S AND UNIT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST EQUIPMENT DATA
- MAST AB-1386/U (NSN 5985-01-381-6341) (EIC:N/A)
- OPERATOR PMCS WITH ELECTRICAL EQUIPMENT MOUNTING MT-6967/G (NSN MT-6968/G (NSN 5975-01-390-9612) (EIC: N/A)