When diagnosing drive problems in heavy trucks with tandem drive axles, how many differentials are typically present?

When diagnosing drive problems in heavy trucks with tandem drive axles, how many differentials are typically present?

• A. One
• B. Two
• C. Three
• D. Four

Answer: (B)

Two differential assemblies are typical with tandem drive axles. Each driven axle has its own differential to split power between the left and right wheels on that axle. This lets the wheels on the same axle rotate at different speeds when turning or traveling over uneven ground, preventing tire scrubbing and drivetrain binding. If there were only a single differential feeding both axles, they would be forced to turn at the same rate, causing steering issues and excessive tire wear. So the standard tandem-drive setup includes a separate differential for each axle.

Two differential assemblies are typical with tandem drive axles. Each driven axle has its own differential to split power between the left and right wheels on that axle. This lets the wheels on the same axle rotate at different speeds when turning or traveling over uneven ground, preventing tire scrubbing and drivetrain binding. If there were only a single differential feeding both axles, they would be forced to turn at the same rate, causing steering issues and excessive tire wear. So the standard tandem-drive setup includes a separate differential for each axle.