Power Jacks M-Series - Machine - Manual (Page 5)

5
Imperial Series – Machine Screw Jacks
3 Maintenance
3.1 Lubrication
Unless otherwise specified, screw jacks are shipped packed with grease which should be sufficient for one
month of normal operation. For normal operation the screw jack and gear boxes should be lubricated once
a month, using one of the following Extreme Pressure greases or their equivalent.
Socony Mobile Oil Co Mobilplex E.P. #1
Texaco Texaco E.P. #1
Gulf Oil Corp Gulf Crown E.P #1
Shell Oil Co Shell Alvania E.P #1
For severe service conditions, the jacks should be lubricated more frequently using one of the above
greases (daily to weekly depending on conditions). If duty is heavy, an automatic lubrication system is
strongly recommended. If ambient temperatures exceed 200°F, consult lubricant manufacturers.
Caution: Where lifting screws are not protected from airborne dirt, dust, etc., bellows
boots should be used. Inspect frequently at regular intervals to be certain that
a lubricating film is present. Lifting screws should never be run dry.
3.2 Rebuild Procedure
Power Jacks recommend the following procedures for assembly and disassembly of machine screw jacks.
1. Tag critical parts to facilitate re-assembly.
2. Mark mating surfaces to insure proper meshing.
3. Clean and lubricate all parts as required.
4. All seals must be replaced when rebuilding.
5. All screws, washers and other small common parts must be replaced if damaged in any way.
6. Replace damaged or frozen lubrication fittings with new ones.
3.3 Required Tools
A bearing puller and press, and common hand tools are necessary for proper assembly and disassembly.
3.4 Disassembly
(Refer to Section 4.3)
1. Remove lifting screw (5) from jack.
2. Remove bottom pipe (4) from shell (3) (upright models) or shell cap (2) (inverted models) or base plate
as applicable.
3. FOR ALL MODELS EXCEPT 100 & 150 TON –
Loosen and remove set screws (1) in cap (2) and remove cap from shell (3)
FOR 100 & 150-TON MODELS –
Loosen the lock screw in the shell and unscrew (Counterclockwise) the base plate from the shell.
Note: It may be necessary to break shell cap or base plate loose with a hammer.
4. Remove gear (6A) or worm gear and nut assembly (6B) from shell (3)
Note: To facilitate removal of the gear from the shell on models with 50-ton or higher load
ratings, partially reassemble the lifting screw into the worm gear (or worm gear and
nut assembly) and use a hoist or pulley block to lift on the screw.