Dear Doctor: I own a 2001 Chevy S-10 pickup with a Vortec 4300 V-6, 4-wheel-drive with 70,000 miles. I want to change the fluids in both the front and rear differentials to full-synthetic. Do you have any suggestions and/or concerns in doing this? What weight oil should I use, keeping in mind that the rear differential is positive traction. Is there one fluid brand you would recommend over others? Edward
Dear Edward: I'm an advocate of full-synthetic fluids and I stock most brands at my shop. As far as brand, they are all good. For the posi-rear differential we use the factory GM synthetic gear oils. The viscosity we use is the same as the factory recommendation for conventional gear oil. You should also change the fluid in the transfer case. If GM recommends a posi additive, then I would use it. The synthetic gear oil, like engine oil, will not thicken when cold and also has less foaming and less drag. All this will help increase gas mileage.
Dear Doctor: I purchased aftermarket bumperettes (square plastic silver pieces) for my 2009 Honda Accord that are placed on the rear bumper to prevent cars from touching my bumper. I believe they are placed on with 3M adhesive. I now notice that the plastic is pitting and I would like to remove them without causing a major problem to my rear bumper. How should they be removed without causing damage to the paint on the original bumper? Norman
Dear Norman: When removing glue-on decal emblems, or in your case poor quality bumper extensions, you can buy specialty decal and glue remover from most auto parts stores. I suggest using a heat gun or hair dryer to heat up the bumper pieces. The heat helps to soften the glue and makes removal easier. Use decal remover to remove the remaining glue, then use wax to seal the surface.
Dear Doctor: I purchased a 2001 Ford F-150 pickup two years ago with 104,000 miles. I've put 12,000 more miles on the truck. Lately, when I turn on the ignition I get a loud squelching sound. Sometimes I get the same sound when I try a second time. After that it turns over fine. Is it something I can fix on my own to keep repair costs down? Michael
Dear Michael: The most common issue is faulty starter gear. The noise is the starter gear not meshing with the ring gear on the flywheel, or flex plate. I suggest removing the starter motor and inspecting the teeth on the ring gear. If you replace the starter motor, then use a quality remanufactured starter motor. If you decide to change the starter motor yourself, then you will find one of the three starter bolts may be hard to access. I've also found in some cases the bolts could be frozen in the transmission case and also be difficult to remove.
Dear Doctor: I have a 2002 Acura RL with 75,000 miles and a 3.5L V-6 engine. While driving two amber-colored lights come on and stay lit: one light is labeled "VSA" (Vehicle Stability Assist) and the other light has a triangle with an exclamation point in the middle. When this happens I pull over, engage the emergency brake and, as instructed in the manual, turn off the engine and press the VSA button. I restart the engine and these amber lights go off, but this problem re-occurs during normal driving activity. What will permanently fix this problem so it doesn't happen anymore? Jeff
Dear Jeff: When you shut the engine off and push the VSA button you are resetting the system without knowing the trouble fault code, so it becomes impossible to tell you what is wrong. The good thing about today's vehicles is the computer systems (with the correct scan tool and a qualified technician) can scan the computer for history, pending and live codes. It would be great to have the VSA light on when the car is brought in to check it.
Dear Doctor: I have a 2009 Chrysler PT Cruiser that is all-stock. I've always loved the old-school hot rods and after a lot of searching I found a set of wheels with baby moon hubcaps that I see are quite popular in Cruiser circles, but they have no cooling holes. Could this become a brake cooling/warping issue? Lou
Dear Lou: There is no question that open style rims offer great brake cooling. The fully enclosed rim design with no vent holes or slots will not cause any brake issues -- unless you are racing on a track. -- Junior Damato, Motor Matters
Junior Damato is an ASE-certified Master Technician.
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