(makes life easier when you replace the tensioner roller)
The timing belt tensioner roller should be replaced every other time the timing belt is replaced, or every 100,000 miles. Taking it off the engine is easy. Just squeeze the tensioner spring, pin it in place, and pull assembly off engine. Putting the new tensioner roller assembly back on, though, can be frustrating.
In most cases, you can reuse the old guide rod and spring with the new roller. You need to compress the spring and pin it in place in order to insert the whole assembly back on the engine. Not easy, as the spring tends to go flying off into space!
Make life easier by creating
your own jig to hold the whole assembly in place. Use scrap pieces
from your workshop. Time: about 20 minutes.
Everything is 3/4" pine, except for the riser board. Lay
out the top and side boards around the tensioner assembly as
shown and screw or nail in place. Mark and drill a 5/16"
hole in the base board where the pivot pin imprints. Use a 5/16"
thick x 3/4" wide x 4" long riser board under the guide
rod/spring assembly. Fasten in place, making sure the fastener
holes are countersunk.
Jig is done!
Pinning the spring is now easier. Wearing safety glasses, squeeze the spring (as shown) with large pliers and push the guide rod through the hole in the hanger plate. Insert pin (bent pin works best) in hole in guide rod. Use a 2x4" safety board at the spring end of the jig to protect yourself if the spring flies loose! Oh, I sometimes find a popsicle stick on top of the riser board (underneath the spring) useful for aligning the guide rod to the hole in the hanger plate.
Once pinned in place, pull from jig and slide tensioner roller assembly into place on front of engine.