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Old 07-29-2010, 02:12 AM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
Here is what I think is the typical recommended special tools and parts list for a drive-belt system overhaul (please correct any errors or omissions):

- alternator/ps/wp drive belt (CRP-Contitech)
- A/C compressor drive belt (CRP-Contitech)
- idler roller (INA is OEM, can also get SKF)
- A/C belt tensioner (INA is OEM, can also get SKF or Ruville or Lemfoerder)
- alternator/ps/wp belt tensioner (INA is OEM, can also get SKF, Ruville, or Lemfoerder)
- alternator, 120Amp (Bosch and Valeo are OEM; replace yours with the same as you're taking out)
- viscious fan clutch (Behr is OEM, Sachs is recommended brand, MFC is not recommended)
- ??? anything else ???

- Dialectric grease for the O-ring on water-cooled alternators only
- 32mm long (~16 inches) thin (~4mm) viscous fan wrench (EBAY, Harbor Freight Tools, Northern Tools, Pelican Parts, Technitool)
- Fan hub bolt counterhold tool, 45mm hole spacing (I6) or 38mm hole spacing (V8) aka fan nut counterhold tool (EBAY, Samsung Tools, Pelican, Technitool)
- 24mm hollow thin socket alternator pulley nut removal tool (only needed if new/rebuilt alternator doesn't have pulley attached)
- Big Fine Hammer, sometimes needed on the fan nut, especially if you don't have the counterhold tool (OSH, Home Depot, ACE)
Note: You can use a screwdriver or make your own counterhold tools for $10 as per the CAD diagrams in this thread.
Note: The BMW 32mm tool (which nobody seems to get, P/N 11 5 040) has an attachment for a torque wrench (but most people don't worry about torque because it's a left-hand thread and the fan spins the other way).
Note: The I6 uses a 45mm spacing tool; old BMW P/N; new BMW P/N
Note: The V8 uses a 38mm spacing tool; old BMW P/N; new BMW P/N
Note: Consider the EBAY fan nut counterhold tool which has the I6 spacing on one end and the V8 spacing on the other.
Note: Edjack implies V8 owners need a recessed counterhold tool for some V8s; so doublecheck here if necessary.
Note: Sometimes the new/rebuilt alternator doesn't come with the pulley so you have to remove yours; most people use a 32mm impact wrench; but BMW sells a specific "hollow thin walled" 24mm socket for this, BMW P/N 12 7 100.
- ??? anything else ???

Note 1: The ONLY way to know if you have mechanical spring or so-called hydraulic piston tensioners is to look; you can even have one of each. No VIN lookup will help you. DO NOT GUESS!
Note 2: You can change from mechanical to hydraulic belt tensioners; but you'll need an additional parts kit.
Note 3: If you plan ahead, you can rebuild the alternator for a fraction of the cost of a remanufactured one; and you'll be sure to have quality bearings.
Note 4: If you are handy, you can make your own fan clutch bolt counterhold tool; just follow the plans outlined in this tool-making DIY.
Note 5: I'm confused but I think the hydraulic tensioners come without the pulley while the mechanical tensioners come with the pulley; I don't know if you can get the pulleys separate from the mechanical tensioners (please correct what I mis-state).

Last edited by bluebee; 08-24-2010 at 01:19 PM.
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