The camshaft gear is actually 2 gears with a spring in between the two. It helps keep a more consistent pressure on the cam chain as the lobes of the cam depress then release the valves. Both gears have a hole that is easily accesible when the timing marks are lined up. Before removing the camshaft(s) you must insert the tool or a tool through these holes to prevent the preload spring from losing it's tension. If that happens then there is another tool to reload the spring pressure.
Page 1.11 in my manual has a pic of the T3880330 tool they recommend using.(dated 2001) It also has a very good step by step procedure for the whole process... I was fairly impressed.
Also,the manual says to remove the right side cover to align the timing marks and rotate the engine but that is not necessary. You can check all the valves by rotating the engine with the starter till the lobes of the camshaft are in the proper position.(Like we do on every other engine) Once you have your readings just align the timing marks on the cam and drive gears, install the backlash gear retaining tools then remove the cams to install the correct shims.
