5.Remove change over pawl (22), spring shaft (23) and change over spring (24) from lever handle assembly (25).
6.Carefully pry change hand wheel (28) from change over gear (20).
7.Remove screw (64), washers (65) and prevailing torque type nut (60) from threaded spacers (94). Remove brake cover assembly (19).
8.Secure drive shaft (3) to prevent rotation and unscrew disk hub (15).
9.Remove friction disk (17), ratchet disk (18) and free spring (16).
10.Remove snap ring (63) from posts on side plate assembly B (12). Remove pawls (14) and pawl spring (13).
Accessing Gear End
1.Remove four prevailing torque type nuts (60) from side plate threaded spacers (94).
2.Remove gear case assembly (1).
3.Remove driver shaft assembly (2).
4.Remove snap ring (62) from load sheave assembly (7) if complete hoist is to be disassembled.
Accessing Load Sheave
Follow steps 1 through 10 in ‘Accessing Brake End’ and steps 1 through 4 in ‘Accessing Gear End’.
1.Slide out Drive shaft (3) from gear end.
2.Carefully remove side plate assembly B (brake side) (12).
3.Remove chain leaders (9) and (11), stripper (10), guide ring B (8) and top hook (45) with top pin (48).
4.Remove splined gear (4) from load sheave assembly (7). Remove load sheave from side plate assembly A (gear side)
(5).
5.Only if necessary, tap side plate threaded spacers (94) from side plate assembly A (gear side) (5).
Bottom Hook Disassembly
1.On single fall hoists remove prevailing torque type nut (77) and capscrew (52). Separate load chain from hook.
2.On 6 ton double fall hoists remove retainer rings (95).
3.Carefully slide idler sheave shaft (96) from hook block (57). Remove idler sheave (56) and remove rollers (97) from idler sheave (56).
4.Slide out idler sheave shaft (96) and remove bottom hook (51).
Cleaning, Inspection and Repair
Use the following procedures to clean and inspect the components of hoist.
Cleaning
Clean all hoist component parts in solvent (except for brake disks). Use of a stiff bristle brush will facilitate removal of accumulated dirt and sediments on gears, shafts and housings. Dry each part using low pressure, filtered compressed air. If brake disks are
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 shaft.
3.Inspect all threaded items and replace those having damaged threads.
4.Inspect brake disks for oil. If brake disks are
5.Measure thickness of brake disks. New brake disk thickness is 3 mm. Discard brake disks if thickness is 2 mm or less.
Repair
Actual repairs are limited to removal of small burrs and other minor surface imperfections. Use a fine stone or emery cloth for this work.
1.Worn or damaged parts must be replaced. Refer to 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 minor nicks, burrs, or galled spots on shafts, bores, pins or spacers.
4.Polish edges of all shaft shoulders to remove small nicks which may have been caused during handling.
5.Remove all nicks and burrs caused by lockwashers.
Hoist Assembly
Refer to Dwg. MHP0773 on page 12.
Load Sheave Assembly
1.Install side plate threaded spacers (94) in side plate assembly A (gear side) (5).
2.Install load sheave (7) in side plate assembly A (5).
3.Apply grease to Bearing A (91) located on end of load sheave (7).
4.Install chain leaders (9) and (11), stripper (10), guide ring B
(8) and top hook (45) on top pin (48) in side plate assembly A (5).
5.Carefully install side plate assembly B (brake end) (12) to engage locating diameters of parts installed in step 4.
6.Push side plates together to ensure all parts are located and secure.
Gear End Assembly
Follow steps 1 through 6 described in ‘Load Sheave Assembly’.
1.Install splined gear (4) on load sheave (7). Install snap ring
(62)on load sheave (7) to secure splined gear (4).
2.Install drive shaft (3) through center of load sheave (7).
3.Install driver shaft gears (2) so gear teeth are correctly timed and spigots locate in bearing sleeves in side plate assembly A (5). Refer to ‘Gear Timing’ section.
4.Apply a thick coat of grease as recommended in “LUBRICATION” section to all gear teeth. Install gear case
(1)over driver shaft (2) to locate and engage gear spigots.
5.Secure gear cover with prevailing torque type nut (60).
10 | MHD56109 - Edition 9 |
