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Chevrolet Silverado: 4WD General Info and Maintenance Schedule

Don't let your 4WD system become faulty; follow your maintenance schedule to ensure your Chevrolet Silverado 1500 can switch into 4WD without any problems.

By Charlie Gaston - June 2, 2015

This article applies to the Chevrolet Silverado 1500 (1999-present).

Four wheel drive, also known as "4WD" or "all-wheel drive" (AWD), means exactly what the name suggests: All four of your vehicle's wheels will operate with the exact same turn-by-turn level of drivability and power, which is ideal for off-road conditions. However, unless you use your vehicle almost specifically for off-road adventures, you won't need to keep your vehicle in 4WD. Plus, running your vehicle in 4WD reduces fuel economy, and that is something most drivers want to avoid. At the opposite end of the spectrum, you also don't want to use your vehicle without ever switching into 4DW, as doing so could cause problems with your 4WD selector light and overall system. Let's go over what you'll need to do to keep your 1500's 4WD system in top working order.

Switching into 4WD

Switching your Silverado 1500 into 4WD is easy. Simply push the "4WD" button; this will automatically switch your vehicle out of "2WD." It's recommended that you only switch into 4WD when driving in snow or mud, or going off-road (also known as "off-roading"). Switch back into 2WD when you return to regular driving conditions. Driving in 4WD can lower your fuel economy considerably.

Figure 1. An illustration of the 4WD system.

Servicing Your System

  • Change transfer case fluid (extreme duty service) at 25,000, 50,000, 75,000, 100,000, 125,000 and 150,000 miles.
  • You'll need a plastic plunger to add the new fluid; be sure to drain the old fluid first, though.
  • It's recommended that you clean the case entirely before topping it off with clean oil.
  • Follow your maintenance schedule for the rest of your vehicle to avoid future problems.
Figure 2. Sample bottle of transfer case fluid.

What You Need to Consider

  • Keep things lubricated by running your system regularly.
  • Check your fluids regularly.
  • If at any point your vehicle does not shift into 4WD, or takes longer than usual to do so, check your transfer case switch. It could be defective.
  • If at any point your vehicle fails to shift into 4WD completely, the culprit is likely a bad solenoid. This is a fairly cheap repair that you can perform at home.
  • Always make sure your buttons are working properly.
Figure 3. 4WD is best for "off-roading."

Common Questions

Can I switch into 4WD when I am not driving off-road?

It's recommended that you only switch into 4WD when driving in mud or snow, or when crossing especially rugged, uneven terrain. Driving on dry or flat and structurally reinforced surfaces in 4WD could lead to extensive damage to your drive shafts, differentials and transfer case, which, depending on the damage, could be costly repairs.

What is the proper fluid for my transfer case?

It's recommended that you use AutoTrak II to top off your transfer case. You'll need about 2 quarts per application. Generally speaking, your DIY cost should be around $16 to $20.

Should I drive a certain amount of distance in 4WD per month?

It's recommended that you drive at least 10 miles in 4WD per month; however, it is best to drive as many miles as possible rather than to avoid to switching into 4WD altogether.

Common Issues

Service Light Appears on the Dashboard

There could be a serious electrical problem with your 4WD system. See a licensed automotive professional for help.

4WD Won't Transfer

If you don't switch your vehicle into 4WD regularly, you could find that your vehicle won't transfer at all, or will take several attempts before transferring. It's recommended that you switch into 4WD high at least once per week and 4WD low at least once per month. Try to drive at least a mile when switching into 4WD high or low, if possible.

4WD Selector Light Won't Go Off or Come On

This common problem can usually be resolved by changing your transfer case fluid, as directed, and/or installing a new selector. The total DIY cost for installing a replacement 4WD selector light is around $55 to $60 including parts. Your total cost should not exceed $75.

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