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To retrofit this new style tensioner, you must plug off the old style tensioner s drain back hole
in the block with a special plug and replace the hollow stud which previously fed oil to the old
style tensioner with a special adapter stud.
1. Milano & GTV-6
Access the old style timing belt tensioner by removing the radiator, auxiliary drive belts
and the timing belt covers.
164 Models
A. Remove the passenger s side front wheel.
B. Remove the strut assembly (four bolts on the bottom and three nuts on the top
of the shock tower).
C. Remove the front inner fender panel.
D. Remove the water pump - A/C belt and the power steering pump belt. Loosen
the rear power steering pump adjusting nut.
E. Remove the radiator hoses from the thermostat using housing/water pump.
F. Remove the two lower timing belt covers.
G. Remove the top engine dog bone brace and the two top timing belt covers.
2. Using a socket on the crankshaft nut, turn the engine clockwise and line up the top
dead center marks at the crankshaft pulley.
3. Very carefully and clearly, mark the relative position of the camshaft drive pulleys in
relation to the cylinder heads. On Milano and GTV6 models, you will also need to
mark the auxiliary drive pulley, as it drives the ignition distributor. Be sure to make
your marks clear and accurate. If you do not mark the cam pulleys you will have to
remove the valve covers in order to reference the factory marks. If you mis-time the
cams, you could bend valves be very careful!
4. Remove the old style timing belt tensioner. Do not lose the retaining nuts and washers,
as you will reuse them later to mount the new style tensioner.
5. Remove the old timing belt (you must remove the Motronic crank sensor if the vehicle
is a 164).
6. Remove the long, hollow oil-feed stud. The stud can be easily removed if you double
nut it and shock it loose by striking it sharply, two or three time on the end with a
brass hammer. Be sure to wear eye protection and do not use a steel hammer - brass
only!
7. Clean the area around the hole for the stud and clean all traces of oil from the threads
in the block. Blow air directly into the hole to dry the threads and to back-flush the oil
out of the oil passage.
8. Apply several drops of Wurth Thread Locker to the 10mm end of the special
conversion stud. Do not use any other type of thread lock. No other sealer or thread
lock compound is recommended. You may wish to shield the area around the hole
with a rag.
9. Double-nut the 8mm end of the special conversion stud and thread it into the block
until the 10mm portion of the stud is flush with the surface. Remove the double nuts.
10. Drill, tap and plug the drain-back hole. Start by drilling it out with a 1/4 drill bit. Put
tape on the bit 1/2 from the end to gauge drilling depth. You may notice that the
passage you are drilling out goes into the block at an angle and is not a straight
passage. This is normal; the passage is cast and not machined. Let your drill bit
follow the passage. When the hole is plugged, the thread locker will compensate for
any irregularities, and since the passage is not under any pressure, it will provide a
positive seal. Use an 8x1.25mm tap and thread the hole halfway. Remove the tap
and clear away any shavings. Then tap the hole the rest of the way. Again, clear
away any shavings.
11. Apply Wurth Thread Locker to plug and thread it into the hole until it is flush. Clean
away any excessive thread locker.
12. Install the new style belt tensioner. Mount it using the same nuts and washers which
retained the old tensioner.
13. Install a new timing belt. Pay close attention to the timing reference marks made
earlier. Retract the tensioner pulley and slip the belt over the tensioner pulley. Double
check that you did not disturb the top dead center position of the crankshaft and that
you engaged the appropriate teeth of the cam drive pulleys. Use great care so as to
maintain proper cam timing. On Milano and GTV6 models you must properly index the
auxiliary drive so as to maintain proper ignition timing.
Adjustment Procedure
This new style tensioner has a temperature-sensitive clutching device. It is important that it is
only adjusted on a cold engine and when the workshop s ambient air temperature is between
59 & 96 degrees F (15-35 degrees C).
1. With the engine cold and positioned at top dead center, loosen both tensioner retaining
nuts. Use a 3/8 square drive inserted into the lift square of the tensioner and rotate
the assembly counterclockwise (into the drive belt) until a resistance is felt.
Caution
Do not use excessive force! Torque applied to the lift square must be at least 11 ft-lbs but no
greater than 18 ft-lbs. Too much force may damage the clutching mechanism.
2. Holding the tensioner in this postion, lock down the tensioner by tightening the
adjustment nut to approximately 15 ft lbs.
3. With the tensioner set in this way rotate the engine clockwise at least four crankshaft
revolutions to seat the belt.
4. On the last revolution, line up the top dead center marks.
5. After performing steps 3 and 4, hold the tensioner with the 3/8 drive in the lift square.
Loosen the adjusting nut and, very slowly, let the tensioner back off, until the position
indicator pointer (see figure A) is lined up with the nominal reference mark.
Caution
Do not let the tensioner back off past the nominal mark, or you will have to repeat the entire
procedure from the beginning.
6. Tighten the adjustment nut and the tensioner pivot nut to 20 ft-lbs.
7. Rotate the engine four complete revolutions in a clockwise direction. Line up top dead
center just as you did in step 4. Verify that the position indicator pointer is still lined up
with the nominal reference mark.
Note: The position indicator pointer will only line up with the nominal reference mark when
the engine is exactly on top dead center and when the engine is stone cold. |
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