For FTRTIL (Model AS20R), the existing 9 mm exhaust choke must be removed, and the existing 6 mm charging choke must be replaced with 9 mm choke to prevent wheel shelling.

For KBIL (Model MGS2), the existing 7 mm exhaust choke must be removed, and the existing 5 mm charging choke must be replaced with 9 mm choke to prevent wheel shelling.

The bearing seat requires CAREBOX 0018529 ISVA lubricant during installation to ensure proper fit and prevent galling.

Axle bearings require Molykote M55 lubricant for proper functioning and reduced friction.

For control arm support, the specified lubricant is Brasol 135 or ESSO Beacon 2, ensuring proper lubrication and wear prevention.

For class C and D screwed assemblies according to DIN 25202, M16 has reduced torque of 10.19 Kg-m (46,000 N) preload at mounting.

For class B screwed assemblies according to DIN 25202, M16 has standard torque of 17.33 Kg-m (78,000 N) preload at mounting.

The nut connecting bogie and car body (nut bogie-car body) must be tightened to 250 Nm torque, strictly respecting prescribed tightening torque.

During brake pneumatic system check, after supplying air to brake units of one axle and sealing the plug, pressure drop should not be higher than 0.2 bars after 10 minutes.

The lateral bump stop support screw M20x100/46 requires tightening torque of 340 Nm, which is higher than primary suspension screw due to different loading conditions.

The primary suspension screw M20x100/46 must be tightened to 170 Nm torque, ensuring proper clamping force for the primary suspension assembly.

The difference in tread diameter of the two wheels on the same axle should not exceed 0.5 mm after tyre turning to ensure balanced running and prevent uneven wear.

The rejectable limit of hollow tyre is more than 5 mm as specified in IRCA part IV. A monitoring limit of 3 mm has been set to study wheel shelling effects.

For axle box temperature 65°C or above but less than 80°C, information must be given to next halting station through control for checking the temperature. Traveling C&W supervisor must also check the temperature.

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 using a calibrated torque wrench, ensuring secure mounting of the security disc.

The mounting force for SKF make CTRBs is 28-32 tonnes, ensuring proper seating of the bearing on the axle journal.

As per RDSO L/No. MC/CTRB/Defects dt-29/12/17, the pressing force for TIMKEN make CTRBs is 17-29T. Earlier specification of 37-42 tonnes has been revised.

The mounted end play at installation for new bearings is 0.025-0.330 mm, while for refurbished bearings it is 0.250-0.500 mm. Refurbished bearings have higher end play due to wear and reconditioning.

The bench end play for Cartridge Taper Roller Bearings is 0.58 - 0.64 mm. This is the internal clearance measured before mounting on the axle.

Before measuring damping force, 10 complete priming cycles must be provided to damper to ensure proper conditioning and accurate readings.

During damping force test of FIAT Dampers, stroke of 50 mm should be provided. Before measuring damping force, 10 complete priming cycles must be given to damper.

In lateral damper, fit the damper in such a way that "THIS SIDE DOWN" sticker must be facing towards the ground. The side with protection cover needs to be kept at upper (elevated) side i.e. to be mounted on bolster.

The correct size of nylon nut is M16 X 1.5 (1.5 mm pitch size). Using standard M16x2 nut damages the damper end spindle threads.

Secondary lateral damper for air spring bogies has drawing no. RDSO/CG/DRG/21049 Alt. 1 or LW05122, with capacity 8000 N and colour RAL 9005 (Black).

Secondary vertical damper for AC coaches has capacity of 3500 N, while for Non-AC coaches it has capacity of 4050 N, a difference of 550 N due to different loading characteristics.

Primary vertical damper requires mounting torque of 100 Nm for M16 size. It has capacity of 2500 N and colour RAL 7012 (Basalt Grey).

After 15 minutes at internal pressure 6.0 kg/cm², no pressure drop is targeted. However, pressure drop should not be more than 1% of Test Pressure.

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.

The dome of Bolster beam has been used as an additional reservoir of 60 litres for each air spring, providing adequate air volume for proper suspension function.

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

The control arm should be coated with "BLASOL 135" solution (Equivalent to Cortec VCI-368 & Molytec EP) during POH/IOH, whether new or reused control arm is used, to prevent wear and corrosion.

For diameters between 230.5 and 230.312 mm, the control arm may be re-machined by providing a cut of 0.3-0.5 mm on the face of control arm. This machining operation should not be carried out more than once.

If the control arm bearing surface reaches a diameter of 230.5 mm (wear exceeding 0.5 mm), whether locally or on the complete surface, the control arm must be rejected.

After proper cleaning of shot blasting surface with air, high performance anti-corrosion epoxy coating must be applied within 30 minutes of shot blasting to prevent oxidation and ensure proper adhesion.

Small pitting holes up to a maximum depth of 4 mm may be permitted provided these are staggered, non-continuous, and not concentrated on the bottom bend portion of the side frame.

There are four main bogie variants: 1267400, 1267334, 1267700, and LW08001. These differ in primary and secondary suspension assemblies, frame assemblies, and brake assemblies to suit different coach types.

The distance between wheels is specified as 1600+2/-1 mm, meaning it can be up to 1602 mm maximum and 1599 mm minimum, ensuring proper track gauge interface.

The diameter of maximum worn wheel is 855 mm for wheels having web thickness 14+3/-0, and 845 mm for wheels having web thickness 17+3/-0. This 10 mm difference accounts for the different wheel designs and their wear characteristics.

The axle distance of the FIAT bogie is 2560 mm, which is the distance between the two axles. This dimension critically affects the bogie's stability at high speeds and its ability to negotiate curves smoothly.