For train services running at speed ≥ 130 Kmph, the wheel sets should be balanced as per RCF specification MDTS-168.

The lateral bump stop support screw M20x100/46 requires tightening torque of 340 Nm.

The bump stop nut M12 requires tightening torque of 70 Nm.

The primary suspension screw M20x100/46 must be tightened to 170 Nm torque.

When length of shelling marks reaches 40 mm, the wheel requires re-profiling to ensure safety.

When depth of shelling marks reaches 1.5 mm, the wheel requires re-profiling to ensure safety.

The limits for permissible maximum flat surfaces on tread for BG ICF coaches is 50 mm as per Railway Board's letter no. 83/M(N)/960/1/Vol I dated 15/18.3.99.

The phonic wheel bolt M8x35 must be tightened to 30 Nm torque as per RDSO letter no MC/CTRB/Genl dated 10.08.2021.

The security disc screw M20x60 must be tightened to 200 Nm torque.

If the temperature difference between two bearings is more than 20°C, the warmer bearing should be removed for inspection.

If axle box temperature is 80°C or more, the coach must be withdrawn from service immediately.

The mounted end play at installation for refurbished bearings should be 0.250-0.500 mm, while for new bearings it is 0.025-0.330 mm.

The mounted end play at installation for new bearings should be 0.025-0.330 mm, while for refurbished bearings it is 0.250-0.500 mm.

The bench end play for Cartridge Taper Roller Bearings is 0.58 - 0.64 mm.

One axle bearing on each bogie is fitted with a current return device. One bearing on each axle is fitted with sensors for speed detection, and the remaining one is without any attachment.

Cartridge Taper Roller Bearing units are self-contained, pre-assembled, pre-lubricated, and fully enclosed units used on wheel sets of LHB coaches.

There are total four bearing units (CTRBs) in each bogie, with different configurations for speed sensors and current return devices.

Secondary vertical dampers and secondary lateral dampers require mounting torque of 70 Nm for M12 size.

Yaw damper requires mounting torque of 170 Nm for M16 size.

Primary vertical damper requires mounting torque of 100 Nm for M16 size.

Yaw damper has capacity of 11000 N and colour RAL 7012 (Basalt Grey) with mounting torque of 170 Nm.

Secondary vertical damper for Non-AC coaches has capacity of 4050 N and colour RAL 3011 (Brown Red).

Secondary vertical damper for AC coaches has capacity of 3500 N and colour RAL 6027 (Light Green).

Primary vertical dampers are coloured RAL 7012 (Basalt Grey) with capacity of 2500 N.

The primary vertical damper has a capacity of 2500 N and colour RAL 7012 (Basalt Grey) with mounting torque of 100 Nm.

During leakage test, the air spring must be installed at design height of 289-294 mm. The final installation height should be adjusted to 294+0/-5 mm.

120 KN capacity air springs are identified by Light green colour coding.

140 KN capacity air springs are identified by Red colour coding.

160 KN capacity air springs are identified by Sky blue colour coding.

The colour coding scheme for air springs is: 180 KN - Grey, 160 KN - Sky blue, 140 KN - Red, and 120 KN - Light green.

The traction centre transmits traction and braking forces between bogie frame and body through a traction lever on the bolster beam pin and two rods.

The bogie frame is linked to the coach body through two yaw dampers, which control rotational movement and enhance high-speed stability.

The bogie frame is linked to the bolster beam through two vertical dampers, a lateral damper, four safety cables, and traction rods.

The Anti-roll bar fitted on the bogie frame maintains a constant, reduced inclination coefficient during running, significantly improving stability while negotiating curves.

The primary suspension comprises two steel coil springs (internal and external) laid out on the Control Arm upper part, positioned using a centering disk with adjustment shims.

The total weight of the FIAT bogie is 6300 Kg, making it a robust yet lightweight structure capable of withstanding dynamic forces.

Each axle is fitted with two brake disks of diameter 640 mm and width 110 mm. These are low ventilation type disks with friction lining in organic material.

The diameter of new wheels on LHB coaches is 915 mm. When worn, the maximum diameter is 855 mm for wheels with web thickness 14+3/-0 or 845 mm for wheels with web thickness 17+3/-0.

The axle distance of the FIAT bogie is 2560 mm, which is the distance between the two axles of the bogie.

The FIAT Bogie used in LHB coaches is a two-axle type bogie featuring both primary and secondary suspension systems, offering superior ride comfort, stability, and safety at high speeds.