Diagnose that Vibration in your Classic Car, Custom Vehicle, or Street Rod

Classic Cars and Trucks, Custom Vehicles, and Street Rods of any model year are supported by the NVH app’s Unlisted Vehicle feature. Simply enter your own vehicle’s axle gear ratio, tire sizes, and engine type, the NVH app can tell you the type of vibration your vehicle is experiencing.

Transmission Direct Drive Warning:

Many vehicles have a transmission gear with a 1:1 gear ratio (also called Direct-Drive). In Direct-Drive, the vehicle’s driveshaft(s) can spin at the same speed as the engine’s crankshaft.

Suppose you drive the vehicle primarily using Direct-Drive during the road test procedure. In that case, a first-order driveshaft speed-related vibration detected by the NVH App may be a first-order engine speed-related vibration. Conversely, An engine speed-related vibration detected by the NVH App may be a driveshaft speed-related vibration.

Classic and vintage vehicles with 2-speed and 3-speed transmissions use Direct-Drive as their high gear. However, modern vehicles have overdrive transmissions and typically do not use the Direct-Drive gear for long durations while driving. Therefore, try to avoid using direct drive when using the NVH app.

Although the NVH App cannot automatically tell the difference between two separate parts rotating at the same speed, the vibration amplitude will increase as you move your phone or tablet closer toward the source of the vibration. Therefore, the amplitude of a driveshaft speed-related vibration should be higher towards the center or rear of the vehicle. 

NOTICE: Electric Vehicles (EV) have fewer moving parts than a traditional Internal Combustion Engine (ICE) and transmission equipped vehicle. There is still a possibility of an EV experiencing a tire speed related vibration or an electric motor speed related vibration. The NVH app is great at detecting tire speed related vibrations, but detecting electric motor speed related vibrations has some limitations depending on the vehicle’s gear reduction gear ratio and the hardware in your phone or tablet**.

Although electric motor vibrations are very rare on vehicles, the electric motors in some electric vehicles rotate at a very high RPM at highway vehicle speeds. The ability of the NVH app to measure electric motor vibrations above 100 Hz (6000 RPM) can be limited by the iPhone hardware, not the app. Many Android phones/tablets have the ability to measure higher frequencies than 100 Hz. It is possible that electric motor vibrations will be detectable at lower vehicle speeds.

**Apple iOS devices with NVH version 4.0 or higher are electric vehicle ready. Android devices with NVH for Android version 3.3 will also be updated to 4.0 in 2022 to work with electric vehicles.


Turn your Phone or Tablet into an all-in-one Noise, Vibration, and Harshness (NVH) diagnostic tool! Purchase our new App to use the internal sensors of your Phone or Tablet to diagnose automotive and truck vibration problems. There are close to 300 individual vibration sources on a typical vehicle; the NVH App knows each one of them and can guide you through the entire diagnostic and repair procedures for each one of them.

What issues have you had with diagnosing vibration, harshness and noise issues?

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