The future of bus transit in new millennium is promising. This
optimism is based on an anticipated long-term slowdown in growth of
suburbs and revitalization of central cities. It reflects and
escalates the public concern with traffic congestion, sprawl and
pollution. This calls for double the use of public transport to
address above issues. It calls for changing the mind-set of society
towards public transports like buses, coaches etc. This could
happen if bus design ensures right comfort, safety & TCO by
ensuring refined bus transport. Hence, it is responsibility of OEMs
to provide the new generation buses and coaches, which will ensure
the public demands of comforts in terms of NVH refinement. This
paper covers the innovative approach used to convert the existing
bus NVH refinement to next level as a short-term solution and with
the intention of articulating NVH strategies for new generation bus
development. This work explains combined experimental and
simulation approach deployed through advanced signal analysis
tools, root cause analysis, source ranking and identifying the
major potential sources. Vehicle measured with non-linear noise
patterns, boom noise, inferior sound quality parameters and high
tactile and floor vibrations. This was because of common chassis
platform, common engine mount system, drive line system and clutch
system for trucks and buses & the absence of acoustic material
in different part of body. Limited CAE analysis was carried out to
identify weak areas in chassis. With all potential solutions,
updated on vehicle, it was found that cabin noise improved by 6-7
dB(A), articulation index improved by 20-25% & vibration
improved about 70% at all load conditions. The bus was successfully
demonstrated to juries for reduced noise and vibration levels and
confirmed for class leading NVH refinement levels. It was possible
with improvement in bus manufacturing processes, critical to
quality component and subsystems for NVH improvement with minimum
cost impact.