Pelican Technical Article: Drive Belt Replacement Wayne R. Dempsey
Time: 1 hour
Tab: $30
Talent:
Tools:
Socket set, 24mm wrench for idler pulley
Applicable Models:
986 Boxster (1997-04) 987 Boxster (2005-08)
Parts Required:
Drive belt
Hot Tip:
Carry a spare main drive belt with you in case of failure
Performance Gain:
No squeaky engine or water pump failure
Complementary Modification:
Replace water pump and/or alternator
This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your Porsche Boxster. The book contains 312 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 950+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website for more details.
Check out some other sample projects from the book:
One of the routine maintenance items that you should perform on your Boxster is the checking and replacement of your accessory drive belt. The belts are driven off of the crankshaft and power accessories such as the water pump, power steering pump, alternator, and air conditioning compressor. There is only one belt on the car that powers it all. It should be checked periodically (every 5,000 miles, or when you change your oil).
The Boxster uses what is known as a poly-ribbed belt (having many channels or ribs on the underside of the belt). The poly-ribbed belt setup utilizes a spring-loaded belt tensioner pulley that provides the proper tension for the belt at all times, making adjustment unnecessary.
When inspecting your belts, the one thing that you want to look for is cracks (see red arrow in Figure 1). If you see any cracks at all, you should replace your belts immediately. The cracks will usually occur on the inside of the belt (the surface that typically rides on the surface of the pulley). With the poly-ribbed belts, this is the grooved surface.
With the poly-ribbed belt, replacement is a snap. Begin by gaining access to the front of the engine. Follow the instructions in Photo 1 to remove the carpet and front engine cover from the rear of the passenger compartment.
The tensioners that hold the belt tight can be easily released using a 24mm wrench. Rotate the tensioner clockwise to release the tension. Simply release the tension on the belt from the tensioner, and then the belt should simply slide off. Release the tension, and then you should be able to unwind the belt from the engine. Tip: if the belt is worn, simply release the tension on it, and snip it with some large tin cutters to pull it out of the car.
Installation of the new belt is easy. Simply slide on most of the new belt onto the pulleys, release the tension on the tensioner, and slide the belt onto the tensioner. Check to make sure that the belt is securely seated in all of the pulleys. Verify that the ribbed portion of the belt is set against the crankshaft pulley. Install the belt in the following order: 1-Water Pump, 2-Alternator, 3-Upper Idler Pulley, 4-Power Steering Pump, 5- Air Conditioning Compressor, 6-Crankshaft, 7-Flexible Idler Pulley, 8- Lower Idler Pulley.
Figure 1
The drive belt on the Boxster is accessible through a trap door compartment cover that's located behind the seats. Move the seats all the way forward, and remove the rear carpet panel by releasing the small snaps that hold it in place (inset Photo, upper right). The clips are screwed onto metal studs. They can be removed using a forked tool available at some shops, or simply slip your finger underneath to provide some upward pressure and pull off. Underneath the carpet, you will see the front engine cover: remove the 7 bolts and two nuts (all 10mm head) that hold on the cover, and it should easily come off. The lower left inset photo shows a belt that is getting very old and showing numerous cracks in the ribbed surface.
With the front engine cover removed you can see all of the various components that are driven by the main belt. On the right is the air conditioning compressor (yellow arrow) and the power steering pump (green arrow). On the left is the alternator (blue arrow). Out of view on the bottom is the water pump. The crankshaft is in the center, shown by the orange arrow. To release tension on the belt, simply place a 24mm socket attached to a breaker bar on the idler and turn it clockwise (lower left).
Here is a brand new crate 3.4L 996 motor direct from Porsche. The various components are: 1-Power Steering Pump, 2-Alternator, 3-Upper Idler Pulley, 4-Water Pump, 5- Air Conditioning Compressor (not installed), 6-Crankshaft, 7-Tensioner Pulley, 8- Lower Idler Pulley. On the lower right is a photo of what a brand new belt looks like.
Comments: Question: Can this cause a squealing noise and occasional erratic upshifting when the clutch is depressed?
January 6, 2012
Wayne at Pelican Parts
Comments: If you have a problem with your alternator, it may be the decoupler pulley, which is a special pulley that is installed on the alternator that allows it to spin up when the engine is accelerating, but free-wheel rotates when the engine is decelerating. This is because the rotating mass of the alternator will work against the belt when the engine is decelerating and can cause premature belt wear. I found this neat video online here from Gates, a well-respected belt manufacturer: http://www.youtube.com/watch?v=hrFcPqZuO3A&feature=related
October 18, 2011
bob
Comments: does anyone have the 997 drive belt tensioner replacement procedure
October 7, 2011
Followup from the Pelican Staff: The Boxster and the 997 are almost identical, so the procedure should be the same. Click on the link for the article. - Wayne at Pelican Parts
Onnfire
Comments: Figured it out: There is a 15mm nut behind the tensioner which was loose. Replacing the alternator was not easy trying to line it up and hold it up while trying to wedge it to line up with the holes. Hope I don't have to ever pull it out again
August 5, 2011
Onnfire
Comments: I have a problem: I am trying to turn the 24mm nut clockwise but it just wants to turn and turn, will do this in both directions. Any ideas would be appreciated
Figured it out: There is a 15mm nut behind the tensioner which was loose. Replacing the alternator was not easy trying to line it up and hold it up while trying to wedge it to line up with the holes. Hope I don't have to ever pull it out again
August 3, 2011
Followup from the Pelican Staff: Thanks for the tip, it can be difficult to see that nut behind there. - Wayne at Pelican Parts
DimitriMartin
Comments: Just a small question. When tightening the idler pulley back on, does it need to be tightened to a specific torque?
Comments: Thanks for the instructions on replacing the belt. Two items I'd like to offer:
1. When removing the carpeting behind the seats that cover the bulkhead. Unscrew the plastic "buttons" instead of prying them out. The edge of my prybar fit the slotted head of the plastic buttons. They screw right out with minimal effort. No prying no tearing the carpet.
2. Watch the edges of the bulkhead cover when you remove it. Very sharp. Cut 3 of my fingers on the edge.
Other than that a pretty simple project. A great to learn about your car and save a few bucks.
May 16, 2011
J Tinsby
Comments: Hi Wayne,
Was looking at my 2011 987 and I don't see the fasteners you show in the inset that allow removal of the carpeting to get at the drive pulleys. Are they under the carpet panel for the main access panel or is the 2011 made differently?
Thanks
J T
April 30, 2011
Followup from the Pelican Staff: Hmm, I haven't had the chance to mess with a 2011 model yet, so I'm not sure. I would imagine if they are not there, then they may be different. The checking of the belts and pulleys should be detailed in the owner's manual, I would think. I would check there for more detailed instructions... - Wayne at Pelican Parts
Kenndogg from across the poind
Comments: Many thanks for this Wayne. Never realised it was so easy to get to until these very easy to follow pics/text.
February 24, 2011
Followup from the Pelican Staff: No sweat! Glad to be of help! - Wayne at Pelican Parts
Ed from England
Comments: Great web site. Fitting the drive belt was easy and made me part of the car. 10/10. Saved me pounds thats English money
February 23, 2011
Followup from the Pelican Staff: Thanks for the kind words. Great wheels on the car (SportDesign IIs - the same ones on my Boxster). - Wayne at Pelican Parts
Check out some other sample projects from the book:
