Serpentine belt (power steering, alternator, fan clutch) and Air conditioning (AC) belt replacement on VW Passat TDI
difficulty: 2/5 because
of tight space
back to 1000q: 2004 2005 VW Passat TDI B5.5 FAQ and
"how to" index
Introduction
This article shows how to remove the serpentine belt and AC belt on a 2004-2005 VW Passat TDI.
If you want to remove the serpentine belt you must first remove the AC belt. The serpentine belt drives the alternator, fan clutch, and power steering. If you are having alternator problems it could be a bad one way clutch inside the pulley. See 1000q: alternator pulley removal for more details. The AC belt drives the air conditioning compressor. To remove the AC compressor, see 1000q: VW Passat AC system remove.
The manual says to inspect the belts every 40,000 miles. If there are broken links or pictures in the article, please post a comment in the VW TDI discussion forum.
Parts
6mm allen wrench
torque wrench
metric (17 or 18?) socket for the AC tensioner
19mm wrench for the serpentine belt tensioner
NOTE: These part numbers are for the 2004-2005 Passat with TDI engine
only!
serpentine belt VW# 038 903 137 t - ecstuning,
from worldimpex
generic, worldimpex
genuine
AC belt VW# 06b 260 849 a - worldimpex
generic, worldimpex
genuine VW, ecstuning
DIY removal procedure
Raise the car, chock the rear wheels, rest the car securely on jack stands (see 1000q: B5 jack points for tips), and make sure the car is safe and secure before doing anything else.
Remove the splash shield and lower grille as needed. See 1000q: lock carrier removal and 1000q: splash shield fastener and removal for more details and pictures.
The fan attached to the fan clutch will be in the way, the pics above are with the fan and lock carrier removed for illustration.
You should be able to remove the AC belt from below without a problem.
However, it's not possible to remove the
plastic radiator fan (the one attached to the fan clutch) with the lock carrier in place. This blocks easy
removal of the serpentine
belt. I think you may be
able to snake the serpentine belt out around the fan with the lock carrier in place but
it'll be tight. Be careful not to bend the radiator fins. The service manual says that you should slide the lock
carrier forward. However, I would first try to get it out before doing unnecessary
work. If you
can't then take off the bumper. If you still can't get it off then begin
to slide the lock carrier forward.
To remove the AC belt (the shorter belt on the passenger side), loosen the 2x 6mm allen bolts holding
the tensioner.
Once they're loose you should be able to move it by hand. If not, use a 17
or 18mm wrench or socket on the tensioner body to loosen it. (I forgot the
exact size). There's a hexagonal knob where the socket goes.
To remove the serpentine belt, put a 19mm wrench on the serpentine
belt tensioner knob and turn counter clockwise to loosen the tensioner. Make sure your
fingers don't get pinched by the serpentine belt during removal!
To tension the AC belt, put a torque wrench on the 6 sided hexagonal knob sticking out of the tensioner and tighten it to 22 ft-lb. (Other 4 cylinder Passat use 18 ft-lb). This sets the tension on the AC belt. Then tighten the 6mm allen bolts to 15 ft-lb. Over tightening the tensioner will damage the bearings. The service manual says that you have to hold the torque wrench on the tensioner at the 7 o'clock position but I don't know why. As a generic recommendation, belts should have about 1/4" deflection when you press on it. Using a torque wrench on the knob is more accurate.
Make sure that the belts are riding on the ribs and centered - if they are off then the belts will be damaged. Double check that all tools are out of the way and start the car to double check the belt path. The rest of installation is the reverse of removal.
Torque specs:
The serpentine belt tensioner is self tensioning.
AC belt tensioner body : 18 ft-lb
2x 6mm allen tensioner bolts: 18 ft-lb
4x 5mm allen bolts for plastic coolant fan: 7 ft-lb
Did you figure out if it was a 17 or 18mm wrench? Share your experience in the VW Passat TDI forum You can find more DIY tips at the forum index or by searching: