Need help with 4WD issues?
You’re not alone!
Many Chevy Blazer owners complain about 4WD engagement and related problems. Thanks to them, finding solutions to address common issues is easier.
So, let’s explore five common Chevy Blazer 4WD issues and their fixes, plus related costs and facts.
This Article Contains:
- 5 Common Chevy Blazer 4WD Problems (+Solutions)
- Cost Estimates for Chevy Blazer 4WD Replacement Parts
- Pressing Issues with Specific Chevy Blazer Models
5 Common Chevy Blazer 4WD Problems (+Solutions)
Here are some Chevy Blazer issues you might encounter:
1. 4WD Won’t Engage or Disengage
Many users struggle with switching between 2WD and 4WD modes.
Here’s what you can do about it:
- Check the locking hubs: If there’s a problem with engaging or disengaging the locking hubs, your vehicle can’t switch between 4WD and 2WD. You may need to service or replace the locking hubs.
- Examine the vacuum hoses: If the vacuum hoses are deteriorating, they won’t maintain the pressure required to engage the locking hubs and activate the 4-wheel drive. You’ll mostly need to replace the vacuum line. Conversely, if the vacuum doesn’t shut off, the locking hubs won’t disengage the front wheels. You might need to replace the vacuum line or vacuum switch.
- Check for seized differentials: In newer models, seized differentials could prevent 4WD from disengaging due to low lubrication. Refill your differential fluid.
- Inspect your electrical connections: Damaged wiring or short circuits near the transfer case control module (TCCM) can cause the 4WD fuse to blow. This may prevent 4-wheel drive engagement or disengagement. Check the wiring harness, clean any corrosion, and replace the fuse box (if multiple fuses shorted out).
- Check for a faulty vacuum actuator: The vacuum actuator and the actuator motor engage and disengage the front differentials to turn 4WD mode on or off. If they don’t work, you’ll need to replace them.
- Inspect your wheels: Tires with different sizes and tread depths can affect the wheel speed and strain drivetrain components, preventing 4WD disengagement. In this case, you’ll mostly need tire replacements.
2. 4Hi Won’t Engage, but 4Lo Does
Some Chevy Blazer drivers experience issues with switching from neutral to 4Hi. However, there’s no problem switching to 4Lo. This is mostly related to a transfer case encoder motor issue.
Here’s what could be wrong:
- Corroded wires: The Transfer Case Control Module (TCCM) and related components have sensors, switches, and solenoids that rely on electrical connections. If the connecting wires become corroded or damaged, it could lead to malfunctions in the 4WD system. Cleaning the wires, replacing damaged wires, and applying dielectric grease may help resolve the issue.
- Faulty transfer case shift motor: For an electronically operated transfer case, you should check the encoder motor (it directs your transmission to switch modes) and its wiring. If you have a faulty encoder motor, you might need to replace it.
3. 4X4 Selector Switch Not Working
If you notice a blinking 4WD dashboard light and can’t transition between 2WD and 4WD modes, you might have a faulty selector switch — possibly with worn or cracked solder joints.
Try resoldering the joints and cleaning the switch buttons. If that doesn’t work, you might need to replace the selector switch.
4. Unusual Noises When 4WD Engaged
The causes of unusual noises after activating 4WD mode include:
- A grinding noise from the transfer case (in all modes) may be due to low lubrication or a metal-on-metal issue (like the chain rubbing against other parts). You can try refilling the fluids or having a mechanic disassemble the transfer case to identify and fix the issue.
- A clicking or clunking noise when turning on the 4WD mode might mean bad CV joints or drivetrain binding damage. You could replace the CV joint, but it’s best to have a professional pinpoint the exact issue before attempting a fix.
- A popping noise can be due to a worn U-joint on the front driveshaft. If you notice any up and down play or damage, you’ll need to replace it.
5. Leaking Transfer Case
If you suspect a leak, you’ll need to check the transfer case.
Fluid leaking from the output shaft seal (a seal to prevent lubricant from leaking) could be due to an overfilled transfer case or faulty seals. You’d need to drain the excess if it’s overfilled or replace the faulty seals.
However, if there’s transfer case fluid coming from between the two transfer case halves, you might need to remove and reassemble the part to reseal it. This is best handled by a professional.
But how much would these fixes cost you?
Cost Estimates for Chevy Blazer 4WD Replacement Parts
Here are estimated costs for replacement parts related to 4WD problems:
- Vacuum Switch: Around $25
- 4WD Switch: $30 to $80
- 4WD Actuator: $80 to $180
- Transfer Case Output Shaft Oil: $200
- Transfer Case Shift Motor: $360 to $705
- Transfer Case: Around $2,435
Next, let’s see which Chevy Blazer models are prone to specific issues.
Pressing Issues with Specific Chevy Blazer Models
Here are details on prominent issues that occurred in specific Chevrolet Blazer models:
- According to carproblemzoo.com, the Chevrolet Blazer models manufactured in 2019, 2002, 2001, 2000, 1999, 1998, 1997, and 1996 commonly experienced wiring and electrical issues.
- Per carcomplaints.com, the 2000 Chevy Blazer had the most problems compared to other years. Fuel gauge issues and transmission failure were the worst among them.
- The 1994 and 2000 Chevy Blazer had multiple reports of gear-shifting troubles.
Overcoming Chevy Blazer 4WD Problems
There isn’t a simple fix to resolve all Chevy Blazer 4WD issues. However, this guide can give you the ideas you need to resolve those problems.
But remember: It can be more effective to consult an expert for car troubles that require technical expertise, like servicing the transfer case.
Why not leave it to AutoNation Mobile Service?
We’re a mobile auto repair and maintenance service that offers upfront pricing and a 12,000-mile or 12-month warranty on repairs.
Contact us to get your 4WD issues resolved right from your driveway.