In the past changing a timing chain or timing belt only required basic tools to get the job done. The camshaft and crankshaft sprockets only went on one way due to the design that used a key-way which only allowed the pulley to go on one way. Alignment marks for the cam and crank were aligned per directions from the service manual. Now many engines have no key-way and the pulleys are pressed on. Since the key-way is not used in increasing number of vehicles, specialty automotive tools are required to properly Align the cam and crank.
Looking for the Marks. Many auto mechanics, when changing a timing chain in the past could just look for the timing marks and not even have to look up the timing mark diagram in the service manual (me included). It was pretty simple, bring the number one cylinder to top dead center and look for the obvious timing marks. Most of the time there was only the crank and only one camshaft to deal with and the pulleys went on one way. Times are changing.
European Influence. In the past, most of the vehicles that did require specialty cam/crank holders and line-up tools were Volkswagen’s, BMW’s and Volvo’s. More cars sold in the US are using European designed or influence engines. They are not as easy to work on, some have VVT (Variable Valve Timing), SOHC (Single Over Head Cam), DOHC (Double Over Head Cam) engines that aren’t nearly as simple. Now with American cars using more engine designs from overseas, auto technicians are finding that the old familiar timing marks that were stamped on the timing covers or pulleys are now gone.
Ford Explorer. One very popular engine that requires cam and crank alignment tools is the German built 4.0 SOHC that is used in Ford Explorers from 1997 and up. Rotunda has been selling specialty tools for years that are used for holding the proper alignment of the cams and crank, since the pulleys can be pressed on in any position. There are eight tools required to align and hold everything in place when aligning the crank and cams. As with many Ford Rotunda specialty tools, once they have been the exclusive supplier of specific dealer required tools for a certain period of time, they start selling these auto tools under the OTC (Owatonna Tool Company) label. The above mentioned Rotunda equivalent auto tools are in a kit, the OTC6488-OCDEM.
All Makes. Ford is not the only manufacturer that uses European designed engines that require these specialty tools. Chevrolet and Chrysler also have gone with import designs for their engines as well. Alignment tools required for Chrysler are usually labeled Miller specialty tools and Chevrolet required specialty tools are usually labeled as Kent Moore. Rotunda, Miller, Kent Moore and OTC specialty tools along with many other brand names are all under the SPX Corporation (Sealed Power Corporation) umbrella.
Professional Repairs. Since there are many different specialty auto tools required for changing timing chains or aligning the old timing chain after having a cylinder head off, this precludes many DIY’s (Do It Yourselfers) from tackling this type of job. This is good news for professional auto repair shops that are willing to invest in specialty auto tools like the OTC6488-OCDEM required to repair these engines. For the well equipped auto repair shop, there will be no shortage of repair work in the future.