This article will outline how to accurately and efficiently calculate which mast and carriage rollers are needed for a specific model in addition to answering how to replace forklift mast rollers. This includes: mast model, bearing part number, outer diameter size.
Installing Lift Bracket Rollers (for all mast models)
To disassemble, follow the sequence in reverse.
|1. Lift Bracket||2. Lift bracket upper rollers||3. Lift bracket middle rollers|
|4. Lift bracket lower rollers||5. Side rollers||6. Inner Mast|
Clearance G: clearance between roller side surface and inner mast thrust surface. This is used to determine the amount of shims at the bearing seat. Measure Clearance G between the side of the surface of the roller and inner mast. Measurement range: 0.1 to 0.5 mm (0.004 to 0.020 in.)
Clearance F: clearance between roller circumference and inner mast thrust surface. This is used to determine the proper size of the rollers. Measurement Range: 1.0 mm (0.04 in.) or less
Clearance G1: clearance between side roller circumference and inner mast side roller thrust surface. Measurement Range: 0.1 to 0.5 mm (0.004 to 0.020 in.)
- Choosing Correct Roller Diameters
Measure clearance F for upper roller 2, middle roller 3, and lower roller 4. If not in the range, replace the rollers. The rollers should function smoothly.
- Adjusting clearance G between the middle roller and thrust plate
Measure clearance G between the middle roller and thrust plate. If not in the measurement range, adjust clearance G.
If clearance G is too high, increase the thickness of shims, and vice versa.
- Adjusting clearance G between lower rollers and inner mast
Measure clearance G between the lower rollers and inner mast. Adjust clearance G as described in the previous point.
- Installing main rollers
Use a driving tool to properly install main rollers on shafts. Do not strike the outer roller surface while installing.
- Adjusting clearance G1 between the side roller and inner mast
Measure the clearance of G1 between the side roller’s rolling contact surface and inner mast. If the measure is not in the range mentioned above, adjust the clearance in the following manner: if G1 clearance is excessive, increase the thickness of the shims and vice versa.
How to Replace Forklift Mast Rollers (for all mast models)
- Measure clearance F between the rollers’ contact surface and masts
If this value is not in the range (1.0 mm / 0.04in, or less), replace with rollers with the correct diameters listed in the table below (figure 1)
- Measure clearance G between the rollers and the masts
If the measured clearances exceeds the range (0.1 to 0.5mm, 0.004 to 0.020 in.)
All mast rollers are identical in shape and size. Thus, clearance F should be 1.0 mm (0.04 in.) or less and clearance G should be 0.1 to 0.5 mm (0.004 to 0.020 in.). If the measured clearances are incorrect, replace the rollers with the correct diameters listed in the below in figure 1.
If measured value clearance G exceeds the standard value, increase the thickness of shims (e) – (j). Standard values can be seen here:
|Item||1 ton class (mm)||2, 3 ton classes (mm)|
Where do I find the part numbers?
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