Timing Belt: Testing and Inspection

Inspection
1. Check the belt carefully and if any damage is found, exchange it with a new one.





1) Vulcanization of the rubber backside. The backside is glossy and non-elastic so that, even if a finger nail is forced into it, no mark is produced.





2) Crack on the rubber belt surface.





3) Abnormal wearing of side face of belt.

Caution: Belts in good condition seem to be cut by a sharp knife.





4) Abnormal tooth wearing
Initial stage
Wearing of side face of load exerting tooth (Fabric puff up, rubber material peel off with color changing to white and fabric become uneven and rough).
Last stage
Fabric wearing of side face of load exerting tooth occurs and rubber is exposed (Length between teeth decrease.).
5) Missing tooth.





2. If any abnormal noise or difficulty in rotating the pulley by hand is noticed, replace the timing belt tensioner and idler pulley.