3.Do not heat a part with a flame to free it for removal unless the part being heated is already worn or damaged beyond repair and no additional damage will occur to other parts. In general, the hoist is designed to permit easy disassembly and assembly. The use of heat or excessive force should not be required.
4.Keep the work area as clean as practical, to prevent dirt and other foreign matter from getting into bearings or other moving parts.
5.When grasping a part in a vise, always use
6.Do not remove any part which is press fit in or on a subassembly unless the removal of that part is necessary for repairs or replacement.
Disassembly
Brake Disc Replacement
1.Unscrew
2.Remove hand chain (46) from hand wheel (31).
3.Remove cotter pin (34), unscrew pinion nut (33) and remove washer (32).
4.Remove hand wheel (31) by holding the load chain (43) and rotating hand wheel (31) counterclockwise until it can be lifted off pinion shaft (13).
5.Remove brake cover (30) and brake disc A (27).
6.Remove ratchet gear (29) and brake disc B (28).
Cleaning, Inspection and Repair
Use the following procedures to clean and inspect the components of the hoist.
Cleaning
Clean all hoist component parts in an acid free solvent (except for the brake disc). The use of a stiff bristle brush will facilitate the removal of accumulated dirt and sediments on the gears and frames. Dry each part using low pressure, filtered compressed air.
Inspection
All disassembled parts should be inspected to determine their fitness for continued use. Pay particular attention to the following:
1.Inspect all gears for worn, cracked, or broken teeth.
2.Inspect shafts for ridges caused by wear. If ridges caused by wear are apparent on shafts, replace the shaft.
3.Inspect all threaded items and replace those having damaged threads.
4.Measure the thickness of the brake discs. If brake discs do not have uniform thickness or are less than 5/64 in. (2 mm) thick replace brake discs.
Repair
Actual repairs are limited to the removal of small burrs and other minor surface imperfections from gears and shafts. Use a fine stone or emery cloth for this work.
1.Worn or damaged parts must be replaced. Refer to the applicable parts listing for specific replacement parts information.
2.Inspect all remaining parts for evidence of damage. Replace or repair any part which is in questionable condition. The cost of the part is often minor in comparison with the cost of redoing the job.
3.Smooth out all nicks, burrs, or galled spots on shafts, bores, pins, and bushings.
4.Examine all gear teeth carefully, and remove nicks and burrs.
5.Polish the edges of all shaft shoulders to remove small nicks which may have been caused during handling.
6.Remove all nicks and burrs caused by lockwashers.
Assembly
CAUTION
•The brake will not operate properly if there is too much oil on the brake discs (27 and 28). Excessive oil or grease on brake components could cause the load to slip.
1.Dip replacement brake discs (27 and 28) in ISO VG32 hydraulic oil or SAE 10 oil for two seconds. Wipe off excess oil.
2.Place brake disc B (28) over hub (26). Brake disc B (28) has a smaller outside diameter than brake disc A (27).
3.Install ratchet gear (29) on hub (26) so recessed face fits over brake disc B. Teeth of ratchet gear (29) must engage pawl (24). Ratchet gear (29) should not rotate counterclockwise and should “click” when rotating clockwise.
4.Place brake disc A (27) on ratchet gear (29).
5.Place brake cover (30) over stay bolts on side plate 1 assembly (1).
6.With brake surface of handwheel (31) towards the brake disc A (27), place handwheel (31) on pinion shaft (13). Rotate handwheel (31) clockwise until clicking occurs.
Hold load chain (43) if necessary.
7.Place washer (32) over pinion (13). Install pinion nut (33) and cotter pin (34). Refer to “Brake Adjustment.”
8.Install hand chain (42) on handwheel (31). Make sure hand chain (42) is seated properly.
9.Place wheel cover (35) over stay bolts. Install
Gears (14)
1/2, 1 and 2 ton units do not use gears with a circle.
On
(Dwg. MHP0044)
NOTICE
• The 1/2 ton hoist has a center pinion gear with only 5 teeth.
10