Auto Doctor: Stick with factory fluids for transmissions

Dear Doctor: I have a 2005 Toyota Tacoma 4x4 V-6 engine and 6-speed manual transmission with 70,000 miles. I had the transmission and differentials fluid changed to full-synthetic Mobil 1. I notice in cold weather I have to force the tranny into reverse and first gear. After a mile or so, shifting gets is normal. Also, for the clutches in the rear I had to add two 4-ounce Kendall additives, so the clutches would release around corners. It appears better, but should I have stayed with the factory oils? -- Frank

Dear Frank: I suggest you remove the aftermarket fluids and replace them with the original fluids. In some cases, changing the fluid type without additives can cause drivability issues. Factory gear fluids have additives that will prevent positive locking type differentials. As for the manual transmission fluid, factory transmission fluids also have additives to keep the synchronizers up to speed to allow smooth gear changes. In extreme cold weather manual shifting can be a bit stiff until the fluid warms up.

Dear Doctor: I have a 2002 Ford Taurus with 145,000 miles. Last summer the alternator went and was replaced with a new one. Then in December it went bad again and was replaced a second time. Now yesterday my battery light went on and my car died. I think the alternator went again! What could be wrong? -- Joanne

Dear Joanne: I see a lot of poorly rebuilt alternators, as well as low voltage and poor ground connections, causing alternator failures. There is a chance that the alternator rebuilding company could be at fault. I use Bosch alternators and they have been the best choice for me. They carry a two-year warranty.

Dear Doctor: My 2003 Honda Accord has an OEM battery sized a little bigger than a typical motorcycle battery, which is rated at 450 cold cranking amps. I want to replace it with a bigger footprint battery that will physically fit fine that is rated at 725 cca. A co-worker told me that by putting in the larger cca battery, I run the risk of ruining the voltage regulator and alternator. Is he right? -- Lee

Dear Lee: Your Accord, like a lot of Hondas, has a battery group size 51. It is a small battery. The larger size battery, such as a group 35 series, will fit right in and will not cause any problems. If fact, the larger battery carries more cold cranking power and reserve energy and will not cause any strain on the charging or electrical system. We upsize batteries anytime we can.

Dear Doctor: I own a 2008 Nissan Pathfinder with less than 60,000 miles. The dealer informed me the passenger seat cushion had to be replaced and they would order one. I heard it was on back-order. It has been over two months and I still don't know when I will get this passenger seat cushion. Any suggestions or what recourse I have? -- Mike

Dear Mike: There is no question that some replacement parts, especially interior parts, can have a long wait time. The vendors that manufacturer parts often wait for multiple orders before producing them. Nothing can be done but to wait, or find a used part to resolve your needs.

Dear Doctor: I'm interested in a new 2013 VW Beetle Convertible with the automatic. Have you driven one yet? -- Ray

Dear Ray: I drove the 60s series model. The 200-horsepower 2.0-liter four-cylinder turbocharged coupled to a 6-speed direct shifting automatic is just like a manual transmission, without a clutch. The audio system by Fender audio has great sound and a powerful subwoofer. Heated multiple adjustable sport seats round out the interior. Driving the Beetle over broken pavement is very forgiving and the suspension absorbs everything the road can give it. The Beetle looks as good as it drives and has come a long way over the years. 

Junior Damato is an ASE-certified Master Technician. Email questions to info@motormatters.biz. Mail questions to: Auto Doctor, 3 Court Circle, Lakeville, MA 02347