Every vehicle on Iowa roads has a differential, and it is important to the proper operation of the vehicle.  But most Marion residents don't have a clue what it is.

The differential compensates for differing wheel speeds. For example, when you turn, the inside tire on the turn travels a much shorter distance than the outside wheel. So the inside wheel of the vehicle must move at a slower speed than the outside wheel. Without a differential, the wheels would hop and scrape while turning.

Have you ever seen the large bulge in the middle of the rear axle of a truck? That's the differential. In a rear-wheel drive vehicle, the differential is located on the back axle. Four-wheel drive vehicles and SUV's have differentials on both the front and the rear axle.

You might expect that the differential is located on the front axle of a front-wheel drive vehicle. You'd be right. But the differential is called a transaxle on a front-wheel drive vehicle because its location allows it to be combined with the transmission.

In an all-wheel drive vehicle, an additional differential or transfer case is located between the front and rear axles. Differentials are strong: They have to be because of the job they do. But those tough parts need proper lubrication. You don't want your differential to seize up. That results in damage to your vehicle.

So you need to have your vehicle differential serviced regularly. It's not a complicated job. At Blair's Ferry Automotive in Marion, we've been servicing differentials for years. The used lubricating fluid is simply drained and then replaced. Some vehicles require specific additives in the differential fluid; your Marion service center will ensure you are getting what your vehicle needs.

The intervals in time or mileage for servicing your differential vary greatly from vehicle to vehicle. Check with your owner's manual or Blair's Ferry Automotive service advisor to find out how often your vehicle differential needs to be serviced.

Blair's Ferry Automotive
1565 Blairs Ferry Rd.
Marion, Iowa 52302
319-447-6310
http://www.blairsferryautomotive.com