Common Repair Issues of a Four Wheel Drive
A four wheel drive (4WD) offers superior power and maneuverability on off-road terrain. You also get increased towing power and your vehicle drives better on icy, snowy, or muddy roads. But a four wheel drive vehicle also has additional parts that can cause additional mechanical problems. A four wheel drive repair can be costly depending on the type of problem that you are confronted with. There are numerous potential problems that you should be aware of if you are planning to purchase or already own a four wheel drive.
Inaccurate Signaling of 4WD Engagement
Sometimes the four wheel drive fails to engage, but the indicator lights on your dashboard tell you a completely different story. It can also happen the other way round with the 4WD being engaged and the lights telling you it is not. In order to determine if the 4WD engages properly the best way is to go to a mechanic that will be able to lift the car and see if the rear wheels are engaged. You can only tell by yourself from the way the car turns. If it turns smoothly then it is not in 4WD mode.To fix this problem you will need to check it there is a problem with the bulb. Alternatively there might be a problem with the transfer case control module.
Getting Stuck in 4WD
Some four wheel drive cars, especially older models, can get stuck in 4WD mode or they can engage in this mode after the vehicle is started. If this happens, the indicator light usually starts to flash. One way to disengage the 4WD if this happens is to turn off the engine. To fix this problem on the spot try to put the vehicle in reverse and move back about 12 feet. Then put it back in drive. The 4WD should be now disengaged. If this does not work try to put the four wheel lever in the four wheel low mode and then to move it to two wheel mode before shutting it off. If the problem persists there might be a problem with the automatic transmission that should be checked by a mechanic.
Broken Transfer Shifter Fork
The transfer shifter fork which makes the shift between the normal drive and 4WD is a piece that is under a lot of pressure. It can break after a while and that might lead to the car slipping from the engaged mode to neutral. If this happens you might need to replace the transfer shift fork.
If you have a 4WD vehicle you will probably drive it on rough roads. Depending on the vehicle, this can lead to cracked chassis outriggers at the point where they join the main frame. The chassis is also susceptible to rust, especially at the low points of the chassis that regularly come into contact with water. Also check for rust signs under the interior carpets. Chassis cracks and rusted spots need to be cleaned, sanded, welded, and sprayed with a layer of rubberized undercoating that will prevent further problems.
Because of driving on hard roads the springs will become saggy and will lead to chassis damage and the hammering of suspension bump stops. The health of the shock absorbers will greatly diminish after a while and leaks will appear, but the only way to determine this is at a mechanical test. If you notice a problem with the suspension check the mounting nuts and bolts to see if the problem is not a result of looseness. Next, inspect tied rods, the steering rack, and the shocks or struts as these may need to be replaced.
Four wheel drives, although powerful and built for hard roads, are not perfect. They suffer from many common faults. But the numerous additional mechanical parts make a failure more probable. A 4WD needs to be constantly checked and taken care of if you want to reduce the maintenance costs and want to keep your vehicle in top condition. Avoid vehicles that have been neglected or worked hard and have your vehicle serviced regularly.