• Find out how 4 Wheel Drive works

• Get an online All Wheel Drive Manual for your car

All Wheel Drive Questions and Answers

This category contains featured questions as examples. They relate to most vehicles.

Question: 2001 Ford Ranger mileage: 61,000. I have automatic four wheel drive.  Recently, the right front hub started to make a loud grinding noise whenever I disengage the four-wheel drive.  The auto hub is not fully disengaging the four wheel drive and, or so I think.  It engages roughly, and disengages smoothly on the fly, but once I stop and restart at say a stop light, there is an awful grinding, "whizzing" noise.  Is this just the hubs that need replacement, or something more serious?  I have been told auto-lockers are no good no matter who you get them from, be it Ford, Chevy, GM.  Instead of replacing the autos, can I just put in manuals, if this is even my problem?  The truck performs just fine once I get into 2WD.

Answer: It sounds like your hubs are bad and the only �fix� is to replace them.  Unfortunately, the only hubs that will work with your 4-wheel drive system are the factory automatic units, which we have found to be high maintenance components.

Question:  1994 Toyota Tercel  4WD  mileage: 70,000.  We ran into trouble with our car and thinking it was the transmission (we couldn't move w/o the gears making a horrible sound) we took it too a transmission shop.  They checked it and said it was not the transmission.  The 4WD gears had no oil so they put oil in it and the car then ran and moved fine in 4WD but the sounds would continue in 2WD.  Therefore, we can drive it in 4WD (I don't know how fast) but we cannot drive it at all in 2 WD.  What is the problem?

Answer: The problem you describe sounds like it is in the transmission/transfer case.  You might want to try a different transmission

Question: 1997 Ford Explorer mileage: 72,000.  When I turn the wheel hard left or right the automatic hubs engage and the whole axle turns, and I am still in two-wheel drive.  Both hubs were updated last year.  Any tips ?

Answer: Check the automatic hubs for proper operation.  They may be faulty.

Question: 1999 Ford Ranger mileage: 54,000.   I am having trouble engaging the 4x4 wheel drive.  When I press the 4x4 button, I hear a tick, tick, and tick from the computer behind the drivers seat, hidden behind the jump seat.  I hit the reset button and that got the light that tells you the 4x4 is engaged to come on but the wheel did not engage and pull when I spun the back wheels.  I reset the computer again and again but the wheel never engaged. 

Answer:  Try replacing the engagement motor on the transfer case.

Question: 1999 Ford Explorer mileage: 110,000.  Problem: Will not shift into 4-wheel drive.  Mechanic replaced the little motor on the transfer case but it still just clicks and does not engage.  This is one of those fancy "push the button on the roof" on the fly gismos, no locking hubs, etc.   He said he tried swapping a couple of modules (1 in the dashboard and another in the side panel behind the drivers seat, all to no avail.  The part he swapped cost $291.  When it did not work he took it out and put the old one back in.  This was greatly appreciated but I still do not have 4-wheel drive.  The mechanic says it is not the transfer case as he can shift it by hand with the motor removed and the little rod exposed. 

Answer: Check wiring for damage.  Check ground wires for good connection.  Check the �push button on the roof� to see that it is working.  Finding electrical problems can be very frustrating and time consuming.

Question: 1999 Dodge Power Ram, miles: 89,020  My 4WD won't engage.  I have replaced the vacuum switch on the transfer case along with the switch on the front axle.  I know that there is pressure in the vacuum lines because I heard a hissing sound when I took the vacuum hoses off of the switch on the transfer case.  The 4 WD lever will shift with no grinding, for both 4l and 4h.  Any help would be appreciated.  Thanks

Answer: The actuator for the four-wheel drive may not be working.  Replacing it may fix your problem.

Question: 1999 Chevrolet k 1500 mileage: 83,300.  My 4-wheel drive does not seem to engage.  The front wheel light on the floor does not come on.  The truck seems to be locked into 4x4 but wheels don�t spin.  The truck lunges hard when engaged seems like its in 4x4 don�t have any clue.  I changed the actuator switch and indicator light.

Answer: Replacing the actuator motor should get the four-wheel drive working right.

Question: 1998 Chevy Blazer mileage: 103,000.  Last week while driving through some nasty weather, I tried to engage the four-wheel option in my Chevy Blazer, and nothing happened.

Answer: The front differential actuator may need replacing.

Question: 1999 Chevrolet S10 blazer mileage: 80,000.  My 4-wheel drive won't shift into 4 wheel. It has the button that shifts on the fly; it has a vacuum diaphragm under the battery that pulls on a cable to the actuator on the front differential.  I pulled off the sensor on the actuator and can see the cable move, but the plunger doesn't come back far enough to be seen by the sensor. Does this mean the actuator is bad?  Also, there is a sensor on the transfer case that has a magnet on this sensor, But after pushing the button the transfer case sounds like it activates. But, nothing moves in front of this sensor to touch the magnet.

Answer:  Yes, the actuator has failed. Replace it with a new unit to repair problem.

Question: 2000 Ford 150 Truck mileage: 115,000.  My Dana 20 transfer case keeps slipping out of 2-hi into neutral.  4-lo and 4-hi work fine.  How do I repair this myself?  And what might be the cause?

Answer:  The Transfer case is worn out.  Replacing it should fix your problem.

Repair Topics / 4 Wheel Drive-1 / 4 Wheel Drive-2

Look up more 4 wheel drive questions in our Car Repair forum section.

Got a Car Repair Question? we will answer it for free.

Replace Air Filter

Check Engine Light