The 2500 Series Chevrolet Truck That Could Not Be Repaired

by | Dec 10, 2016 | auto repair

Another memorable “can’t be fixed” vehicle was a full-sized 2500 series Chevrolet Truck. This vehicle had been sold used by a local dealership; it had a vibration problem. The service department tried several things to fix the vibration but could not. That is when I received a phone call from the service manager asking for help.
While listening to the service manager describe the history of this vehicle, I learned that in an attempt to repair the vibration, the dealership service department balanced the tires several times and had the driveshafts balanced; nothing would fix this vibration. The vehicle must be a Lemon; it can’t be fixed.
Using the same diagnostic procedure outlined in our new NVH smartphone app, the technician working on the truck and I performed a quick road test of the Truck. The road test results indicated that the vehicle had a third-order tire speed-related vibration. As the NVH app’s diagnostic help file indicates, third-order tire speed-related vibrations are only caused by a few select problems on the vehicle.
  1. A tire or wheel with excessive runout
  2. Stiff spots in the tire’s sidewalls (Force Variation)
  3. Failed or binding Constant Velocity (CV) Joints
  4. Drive axle problems
While the technician and I were working our way down this list of items to check, we could not find any problems with any parts, but I did notice that the front of the vehicle was sitting a little higher than I thought it should. We checked the ride height of this truck to another truck on the sales lot; it was too high. This truck uses Torsion bars as the front suspension springs. The torsion bar tension (and ride height) are adjustable with bolts at the cross member attached to the frame.
We adjusted the Torsion bars to set the front suspension ride height to the proper level and performed another road test; the vibration was gone! Excessive inner Tri-Pod CV joint angles caused the vibration. The CV joint inner shaft was binding on the outer housing three times per revolution of the tire. This caused the third-order tire speed-related vibration.
There were no bad parts on this vehicle; only a simple suspension ride height adjustment was necessary to repair the vibration. One very unhappy customer was the result. Hundreds of dollars were wasted on attempted repairs, many hours of labor were wasted because nobody knew how to diagnose a vibration problem; they were guessing! The NVH app eliminates the guesswork in vibration diagnosis and guides you step-by-step through the entire diagnostic and repair procedure. Get the NVH app today by clicking on the link below.

What the app can do

The NVH app is designed to automatically detect the type of vibration your vehicle is experiencing, provided the instructions of the road test procedure are followed.

There are 14 types of vibrations the NVH app can automatically detect:

  • Tire speed-related (1st, 2nd, and 3rd order vibrations)
  • Driveshaft speed-related (1st, 2nd, and 3rd order vibrations)
  • Engine speed-related (0.5, 1st, 2nd, 3rd, 4th, 5th, and 6th order vibrations)
  • Electric Motor Speed Related (1st order vibrations)

Each type of vibration has unique causes. A vibration type is not the same thing as a vibration source. There are many possible causes (sources) for each vibration type. The NVH app includes step-by-step instructions on locating the vibration source once the app has identified the type of vibration.

What the app cannot do

  •  The NVH App cannot automatically tell you the source of a vibration
  • Although the NVH app is excellent at identifying the type of vibration your vehicle is experiencing, you or someone else will need to follow the diagnostic steps described in the app help files to identify the exact cause or source of the vibration.

There are almost 300 possible sources of vibration concerns in today’s vehicles

T1 Diagnostic Help

THE NVH APP IS HERE!

Turn your Phone or Tablet into a Vibration diagnostic tool! Purchase our new App to use the internal sensors of your Phone or Tablet to diagnose the type of vibration your car or truck is experiencing. 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.

278 Ways To Fix Vibrations

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