1. Conventional Elevators (In Ground)
    1. Rough upstarts only (Westinghouse Elevators before 1989): Remove lower wiper in impact plate (See Diagram 2.)
    2. Rough down-start noise in Dover Elevators predating 1995 or in Southeastern Elevators: These units have Babbitt bearings integrated with heads. If the elevator overshoots the top floor and impacts the stop ring, the bearing will deform and proper clearance will be removed. Remove head and machine integral Babbitt bearing to restore proper clearance. Removing 0.005”/0.010” will usually restore proper functioning of elevator. (See Diagram 3.)

      Diagram 2:

  2. Dual Piston Telescopics
    1. Leaks or synchronizing problems should be treated as safety concerns. One piston not extending fully will cause uneven distribution of weight on the crosshead. Severe cases cause the elevator cab to rack. Newer units are equipped with a pressure deferential switch when the pressure differential becomes too large. Jacks are automatically synchronized. Jacks not equipped with this feature should be resynchronized on regular schedules based on the condition of the seals and a visual inspection of the synchronized jacks.
    2. If you are pulling your hair out over trying to figure out the type of elevator head, please carefully measure the piston and take three photographs of this head, each photo from a different angle, and send them to us by mail (P.O. Box 968, Cedar Hill, TX 75106) or by e-mail ( Please attach a cover letter describing your difficulties, the location of the site, and your business information (your name, company name, location, and phone or e-mail. Also, please measure the jack as precisely as possible. This information will enable us to assist you much better.
  3. Holeless Dual Piston
    1. When riding holeless hydraulic elevator, a common problem is making noise when leveling at top floor or on slow speed.
    2. How to check and find out if the packing is too tight: Use light grease to make a paste. Rub on one plunger and make a run on the elevator. If the elevator is still making noise, rub the paste on the plunger a second time. Repack faulty piston. Check for proper bearing clearance.
  4. Synchronous Telescoping Pistons
    1. External leaks will cause synchronizing problems, by causing the small piston to not fully extend.
    2. Internal leakage of bottom or internal seals will cause the large piston to not fully extend.

All Jacks

Measuring Jack Formulas

  1. Regular Measuring Tape: Please note: Measure Jack with regular tape to the nearest 16 th of an inch.
    Example: Jack “X” measures 17-1/16”
    1. Divide the fraction. Ex: 1/16 or 1 ÷ 16 = 0.0625
      This means that the dimension of the circumference of Jack “X” is 17.062
    2. Divide the circumference by Pi. Ex: 17.062 ÷ 3.142= 5.437 or 5-7/16”
      The Seal Size is F05437-LF1.
  2. Pi Measuring Tape with a 100ths range:
    From Normal Size: -0.04
    5.43 or 5.44
    Range 5.42-5.44
  3. Pi Measuring Tape with a 64ths range:
    Range 5-26/64 – 5-29/64

Fine Measuring to Determine Seal Type (LF1, LF2, E, Oversize)
LF1 – These are –0.02”, +0.02” nominal size, -1/64, +1/64
LF2 – Telescopic and Roped Hydros
E – These are –0.02, -0.04, -2/64, -4/64
O – These are –0.040, -4/64 (Does not apply to United heads.)

Measuring Bearing Clearance

Proper bearing clearance is critical to elevator performance. Most jacks perform well with 0.020”/0.035” clearance with some exceptions. For example, Schindler F2 head (MPH) has minimal clearance due to the design of the small cross-section of the seal. To measure for proper bearing clearance, a magnetic base and dial indicator are necessary. Proper Procedure for Measurement

  1. Follow all procedures for safely removing packing.
  2. Remove all packing and wipers.
  3. Reinstall separate bearings and lantern rings.
  4. Replace at least two fasteners to head assembly.
  5. Secure magnetic base to casing or head. Place the tip of the dial indicator at right angles to the jack surface.
  6. Gently pry jack into and away from the dial indicator. Notate the range of motion.
  7. Repeat 5 & 6 at right angle to first reading.
  8. The largest reading is your bearing clearance. Special bearings should be made if the clearance exceeds 0.040” Dimensions above this range shorten the packing life and increase seal-related maintance


Oil-Related Troubleshooting

Resources: Gorman Co., Inc. Oil Analysis Kit


Viscosity-Related Problems
Low viscosity causes tight packing. High viscosity causes car to overshoot floor. Low viscosity problems add to viscosity related problems. Add IU9891 Caterpillar Hydraulic oil additive or Maxton Valve Maxglide.
1%-2% total volume of elevator
High viscosity problems: You must replace tank oil with ISO 32 grade oil.

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