In order to remove the timing belt, it is necessary to first remove the timing belt tensioner and the wheel on the ADR engine by being very careful to keep the spring securely attached with a drill bit, then loosen the bolt of the eccentric hub, and the tensioner mounting bolts and pull it out of the front of the engine. In case of AAE, ABK and AAD engines, unscrew the bolt on the slot and unbolt the tensioner assembly on the front, take off the tensioner wheel on the stud. On the ACE engine remove the nut and remove the hub on the front stud. Then remove the screwdriver bolt of the camshaft sprocket keeping the sprocket fixed in place with a tool and then screwdriver bolt, washer, sprocket and key. In the case of the intermediate shaft sprocket, unscrew the bolt in holding the sprocket and then remove the bolt, the sprocket and the key. To change the crankshaft sprocket, unscrew the bolt and then remove the sprocket, making sure that the crankshaft remains stationary; on a manual gearbox disengage the top gear and hold the footbride, on an automatic disengage the transmission front cover with a screwdriver in the ring gear. Wipe down all the sprockers and inspect wear and tear and make sure the tensioner wheel glides without friction and change it in case of need. To refit, find the crankshaft sprocker and tighten the bolt to the required torque without being allowed to rotate keeping the crankshaft stationary so that piston-valve contact does not occur, and refit the timing belt. In the case of the intermediate shaft sprocket, find the key, re-assemble sprocket and bolt and tighten bolt to set torque with sprocket in hand. Repeat with camshaft sprocket making sure that the narrow web is facing direction of travel and then replace timing belt. Lastly, re-fit the tensioner and tensioner wheel ensuring the spring is not lost in ADR engines but is left loose in the slot in AAE, ABK, and AAD engines and the nut is left loose in the slot of ACE engines.