I just spent 10 minutes searching on my drive for the official TSB that explains how to do it but could not locate it (with drawing of mechanical tensioner). But I did locate this post on the old Alfa Digest site. Could not tell who posted it. But as I recall from the TSB, sounds correct.
Adjustment procedure new style, non oil-fed, v-6 timing belt tensioner
(reference video tape - part # 608-97518)
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 deg f. (150 - 350 c.).
1) With engine cold and positioned at
top dead center, loosen both tensioner retaining nuts.
Use a 3/8 square drive inserted into the lift
square (see figure "a" attached) of the tensioner
and rotate the assembly counter-clockwise
(into the drive belt) until a resistance is felt.
Do not use excessive force! Torque applied to the lift
square must be at least 11 foot pounds but no greater
than 18 footpounds. Too much force may damage the
2) Holding the tensioner in this
position, lock down the tensioner by tightening the
adjustment nut to approximately 15 foot pounds.
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.
Do not back up the engine at anytime (during the
adjustment procedure). If you accidently pass TDC
keep going and bring it around again. Do not backup!
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 is lined up with the nominal
Do not let the tensioner back off past the nominal mark
or you will have to repeat the entire procedure from
6) Tighten the adjustment nut
and the tensioner pivot nut to 20 foot pounds.
7) Rotate the engine several
more 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
polnter 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.
*Note: More belts have slipped using the mechanical tensioner. So I would advise doing it right & by the "numbers" as they say...
**Also note that these instruction start as if tensioner is already in place and are adjustment instructions. Obviously, if replacing the belt make sure to have cams, crank, and distributor lined-up properly before removing old belt. Install new belt by coming around clock-wise, being careful not to disturb the idler gear (drives the oil pump and distributor). Then go ahead with the procedure.
Hope this helps,
Last edited by ToonRboy; 04-22-2017 at 09:43 AM.