Hoist Test

After a road test, it is sometimes useful to do a similar test on a hoist. (Use an axle hoist, not a frame hoist. An axle hoist will not change the driveline angles. If only a frame hoist is available, axle stands should be used.)
1. Elevate the front wheels slightly, check to make sure that both wheels are turning freely, start and run the engine rpm up with the vehicle in gear.
2. Explore the speed range of concern using the drive/cruise/coast/float tests.
3. A coast down in N (neutral) should also be conducted. If the vehicle is free of vibration when operating at a steady indicated speed and behaves very differently in drive and coast, an axle concern is likely.