8. If you re replacing the AC compressor drive belt as well, it s time to loosen its belt tensioner. The AC compressor belt tensioner is very obvious under the front of the car. Loosen the 13mm bolt, then the 10mm bolt to relieve the force, just like you did for the main serpentine belt. AC Compressor 13mm 17mm 10mm Looking up the front of the engine from under the radiator. (Picture taken with belt under tension.) 9. Remove the AC belt from around the compressor, idler, and engine. As I mentioned earlier, my AC belt looked fine and I probably could have lived with it for many more miles, therefore I have no egregious pictures of a truly worn belt. 10. Install your new AC belt, routing it just as the old one was. The AC compressor pulley is straightforward and easy to get the new belt centered. The main engine pulley has two sets of grooves: the rearmost set is for the AC belt and is separated from the main serpentine path by a taller rib. Make sure the AC belt is riding in the correct set of grooves and the belt is centered over the compressor pulley. The idler pulley should be pushing into the back (smooth side) of the belt, just as pictured above.
11. The belt tensioner is very easy to set up. Pre-tighten the 13mm bolt, just enough to take up play but not so much that you can t turn the tensioner. Use your 17mm socket to turn the large, cast-in-place hex (shown in red in the previous illustration) clockwise until the 10mm bolt bottoms out in the slot. Most of the travel will be simply moving the idler into contact with the belt, but the last fourth of travel will be used to compress the spring in the tensioner, so it s a bit tougher. With the 10mm bolt bottomed out against the top of the slot, tighten securely*. Remove your 17mm socket and securely tighten the 13mm bolt*. *Often, the TIS does not give tightening torques for various screws. In most cases, the TIS recommends tightening torques based on screw size and strength rating. Unless there is a specific reason to tighten a screw to a given torque value, most manufacturers and guidebooks recommend torque values for screws that create a nominal amount of tensile preload in the screw body. Anyone who has worked with screws and bolts before knows what tight feels like and that s what the torque values usually represent. Long story short, tighten the bolts until they re tight, keeping in mind that overtightening could strip the threads or break the bolt, and undertightening could result in the belt tensioner slipping. 17mm 10mm Semi-tighten 13mm bolt (under 17mm) to take up play. Turn 17mm cast-in hex clockwise until 10mm bolt bottoms out at top of slot. Tighten the 10mm bolt. Tighten 13mm bolt.
12. Install your new main serpentine belt as shown in the diagram from the TIS (below). The belt takes quite a few twists and turns, so make sure you ve followed the diagram. I found it easiest to install the belt by lying under the front of the car. Make certain that you ve properly located the belt in all of the pulleys so that the grooves match up. All of the ribbed pulleys have large outside lips that you should be able to see next to a properly installed belt. If your belt looks like it s teetering on the edge of a pulley (or if you see an extra groove in the pulley), you need to reposition the belt. Belt routing diagram per TIS
13. The belt tensioner for the main serpentine belt is analogous to the AC belt, but access is more difficult because it s not as easily visible. I used my 1/2 ratchet with a 3 extension and 17mm socket to turn the cast-in-place nut. I used my 3/8 ratchet with a 6 extension and 13mm socket to secure the tensioner once forced into position. Start by tightening the pivot bolt A to take up play, but not so tight as to inhibit rotation. Then, turn the 17mm cast-in-place nut counter-clockwise to bring the B bolt to the top of its slot. This belt tensioner seemed to require much more force than the AC belt, so I had to use an extension on my big wrench to turn the 17mm hex. Once the belt tensioner is loaded, tighten the 13mm B bolt securely. Remove the 17mm wrench and tighten the 13mm A bolt securely. I found that when I removed the tension with the 17mm wrench, the belt tensioner seemed to relax a bit. I suspect this was because I didn t properly pre-tighten A enough. The TIS lists the tightening torques for the two 13mm screws based on screw strength and build date (see explanation in Section 11): 22 Nm for up to 9/98, 30 Nm for 9/98 and after. I didn t use a torque wrench, so if my belts start squealing we ll know I didn t tighten the bolts enough. 13mm B 17mm 13mm A Large belt tensioner, picture taken through radiator. Semitighten 13 mm A to take up play. Turn 17mm cast-in hex counter-clockwise until 13mm B bottoms out in slot. Tighten B. Tighten A. (Picture taken with tensioner loose.)
14. Reinstall the fan by inserting it up from underneath the car. It is safe to handle the fan by the blades provided you don t apply excessive force to them. Just to play it safe, pretend the fan is coated in old TNT and you should be fine. Once you get the fan into position on the water pump pulley, turn the fan by the blades to get it started on the threads. After about half a turn onto the threads, you ll need to use your big wrench to turn the nut. Once the nut is tight, install your special tool, but this time on the opposite side of the pulley. Use your big wrench and tighten the nut by pushing it counter-clockwise. Remember, the fan uses left handed threads, so you ll feel like your pushing backwards. The TIS recommends a tightening torque of 40Nm, but unless you have their special tool there s no easy way to use a torque wrench. In this case, I ballparked 40Nm with muscle strain. 15. At this point you re basically done, but before you reinstall the bottom cover you should give things a once over: Make sure the belts are properly routed, properly seated, and properly tensioned. Make sure the fan has been reinstalled, tightened, and not damaged. You may wish to start the engine to listen for noises. Make sure when you first start the engine you are not standing next to, over, or under the fan. If you happened to damage the fan during removal/installation, it may come apart when you run the engine. For that matter, I make it a point to NEVER be in the explosion path of the fan whenever the engine is running. 16. Once you are comfortable that everything looks good, put the cover back on the underside of the engine and take the car down off your jackstands. You re done!