RockAuto now offers Zimmermann Rotors and Brake Pads. Zimmermann is known for their high quality brake parts for European makes like BMW, Mercedes-Benz, Porsche, Volvo and more. Zimmermann rotors are designed to absorb and dissipate heat efficiently for better braking and improved rotor lifespan and many meet the strict European ECE R90 approval for brakes. Zimmermann also offers a coated rotor line called Coat Z, which provides enhanced corrosion resistance for drivers in high salt and precipitation areas.

You can find Zimmermann Rotors and Brake Pads in the "Brake & Wheel Hub" category of the RockAuto.com catalog for many European vehicles.

After a year of searching for a low mileage 2012 Hyundai Genesis Sedan with a 4.6L engine, I finally found one with 20k miles. It had HID projector headlamps which I was excited about as all my other vehicles had "old fashion" halogen bulbs. But, when I bought it, I noticed the headlamp range was severely limited, maybe five feet in front of the car. I decided to adjust the level with the leveling screws, but they were far down into the engine bay so I went out and bought a very long screwdriver only to find out the screws were stripped by the previous owner who was probably trying to fix the same issue.

Defeated, I took the car to two different dealers to have them check it out. They both told me I had to replace the headlamp assemblies which would of cost well over a thousand dollars a piece from them. Of course I said "No thanks!" There had to be another solution.

Soon afterwards while changing the oil, I noticed a tiny little sensor hanging loose from the sub-frame close to a tiny and conveniently located socket on the control arm. The sensor snapped into that socket exactly! When I started the car, the headlamps did a new "dance" and leveled themselves out perfectly which finally solved my headlamp problem! They still work perfectly to this day. Turns out, that generation of Genesis had auto-leveling headlamps based on the weight in the vehicle. The dealerships never mentioned this as a feature nor checked into that system (I didn't know it was a feature myself). Even if I had paid thousands of dollars for new headlamp assemblies, the issue may not have been fixed! Lesson learned - look for anything out of place while performing routine maintenance! 

Paul in Michigan

Many electric vehicles have transmission fluids and filters that need to be changed even though they have neither conventional internal combustion engines (ICE) nor conventional transmissions. Gear oil or automatic transmission fluid is used to lubricate and cool the reduction gear sets/units. The oil/fluid cools the electric propulsion motor(s) on some vehicles as well.

Electric vehicles are often said to have a single speed, but that single speed is not the speed of the spinning electric motor(s). A set of reduction gears is used to convert the high speed, low torque output of the electric motor to the lower speed, higher torque output needed to turn the vehicle's wheels. This is similar to the differential turning a conventional car's axle shafts reducing the speed of the driveshaft.

Gear oil is typically used to lubricate/cool a conventional differential. Similarly, gear oil is used in many reduction gear units. Automatic transmission fluid is also commonly used because car manufacturers learned how to design hybrid vehicles that have both ICE transmissions and electric motor reduction gear sets sharing the same fluid.

Specific automatic transmission fluid or gear oil is required by the vehicle manufacturer depending on the model/year and sometimes also by the drivetrain option. For example, Ford's base-level electric Mustang Mach-E, might use gear oil in the front reduction gear unit and transmission fluid in the rear unit, while the GT version of the Mach-E may use automatic transmission fluid in both the front and rear reduction gear sets.

For some models/years, electric car manufacturers may specify an "electrical driveline fluid" rather than an automatic transmission fluid that is also used in ICE powered (and other electric) vehicles. Electrically conductive driveline fluid may be necessary when the vehicle has a "wet axle" where the fluid cools the electric propulsion motor as well as the reduction gear set. (Circulating regular automatic transmission fluid through a powerful electric motor can be a bad idea because regular automatic transmission fluid might act as an electrical insulator. When that insulating effect momentarily breaks down, there could be arcing that damages parts like bearings, gears and seals. Arcing could also speed up oxidation (deterioration) of the fluid itself.)

Follow the reduction gear set fluid replacement intervals recommended by the electric vehicle manufacturer, but be aware that manufacturers might tend to downplay electrical vehicles' maintenance needs so they compare favorably with ICE powered vehicles. Changing oil/fluid and filters more frequently could make gear sets last longer, especially in harsh driving conditions (hot, dirty, high speed, towing...). Changing the reduction gear fluid and filter is often a job appropriate for a DIYer who is comfortable doing similar work on conventional cars. For example, the spin-on filters typically used on Tesla front and rear reduction gear sets look just like ICE oil filters.

Tesla Service Kit w/ Filter, Fluid, Seals & Drain Plug

See the reduction gear set filter and fluid/oil for specific electric vehicles under the "Transmission-Automatic" and "Drivetrain" categories in the RockAuto.com catalog. A "Transmission Service Kit" may be available that conveniently includes the reduction gear set filter, fluid, gaskets, drain plug and other necessary parts all under one part number.

Tom Taylor,
RockAuto.com

To read more of Tom's articles, click this link and choose from story titles on the Newsletter Archives page.