SKF Timing Belt Kits - SKF.com

Failure analysis overview
Troubleshooting the ATBT set-up:
1. The mounting bolt is not correctly torqued (to
car manufacturer recommendations). If it is not
tightened, the tensioner will gradually loosen under
running, and the indicator arm may come into
contact with the end stop. The engine begins to run
rough as the timing is affected, before failing.
2. Incorrect mounting (location pegs or holes are not
correctly located).
3. Correct set-up is not possible for proper running
of the engine. Check for correct back plate locating
point; some engines can indicate incorrect
alternatives causing visual error.
4. Unevenness between the mounted tensioner plate
and the engine block can cause incorrect tension/
belt run out or even block bearing rotation. Check for
debris or possible fouling points on mounting.
5. The indicator arm is not set to the correct tension
position. You need to turn the engine twice to
reconfirm a correct position. If it is not in the advised
position, remount and perform the set up process
again. Don’t take the risk, play it safe and be sure.
Hydraulic tensioner
Apart from the traditional weaknesses on the tensioner
pulley component, the actuator part can be affected by
wear and premature failure.
Common failure causes:
1. An oil leakage through the seal. Even the smallest
leak in the actuator through time will cause gradual
loss of damping effect and possible belt damage
(ripped teeth from poor tension may be found).
2. Failure in the spring or valves will lead to system
failure, and probably engine damage, very quickly.
To maintain correct function, this damping control unit
should be changed at the same period as the timing belt
and pulleys (around 70,000 mi/around 110 000 km).
14
1. Wrong torque
The indicator arm on the ATBT is broken.
1. Oil leak through the seal of the hydraulic tensioner