*** DIY Belt Tensioner Replacement With Pictures ***
 

Remove 4 clips and remove cover. Close up of clips (pull pin straight up to release)

http://forum.e46fanatics.com/attachm...1&d=1169870102







Remove to additional screws that enclose the fan blade. Facing the car on the left. Remove torx screw and unhook the two electrical connections. Facing the car on the right side, remove the pull-pin clip just like the first photo.

http://forum.e46fanatics.com/attachm...1&d=1169870102








Remove the fan and fan shroud. The fan loosens up left to right when facing the car.




Use a 16mm or 5/8” socket wrench to release the tension on the tensioner to release the belt counter clockwise.

http://forum.e46fanatics.com/attachm...1&d=1169870102




Remove dust cover from the top pulley and remove to access the tensioner bolts below.

http://forum.e46fanatics.com/attachm...1&d=1169870102



Remove top and bottom tensioner bolts.

http://forum.e46fanatics.com/attachm...1&d=1169870430






Install is the reverse. Here’s a diagram of the belt if you forgot to take a picture.

http://forum.e46fanatics.com/attachm...1&d=1169870430




The hardest part is getting the fan back on. Be patience and remember to spin the fan right to left when putting it back on.

Enjoy and I hope this helps all..



Created by Almario

Very nice write up:thumbup:

Im trying to change my deflection pulley since its squealing like crazy, but everywhere i search for a part, I always find these two types of pulleys.

On Rockauto.com I find this...

RUVILLE Part # 11281738605 {Deflection pulley #11281748130}
http://67.129.153.73/CGv2Production/...1281738605.jpg

On BMAAuto.com, a search for 11281748130 idler pulley shows me these two.
http://catimages2.sophio.com/webapp/...1281748130.jpg

Can I use these two parts interchangeably?? One is flat, the other has a raised bolt head?

2 types? lol. Thats the same part...The 2nd picture is just showing you the front and back of the same part. The raised side is the back, the flat is the front. If you look closely at the picture in the DIY above captioned with "
Remove top and bottom tensioner bolts." You will see to the right on the top bolt the place where the raised part with the small nipple of the deflection pulley mounts onto the alternator.

ahh thanks for clearing that up. I got confused since I see two part numbers for it... im not sure why they do that.

You mean Ruville? 3rd part part manufactures and disrtibutors will typically list their own internal part number. Thats to be expected. They may also provide the OEM part number for an additional reference to clarify the application. It can be confusing though.


BTW make sure you get the 11281748130 and not 11281748131. My local BMW dealer handed me the 31 by mistake even though I asked for the 30. :thumbdwn:
Took a sec for it to register when I looked at it then I got him to exchange it...

Got it... The 31 isnt offset like the 30 is. Thanks for your help! :thumbsup:

http://i70.photobucket.com/albums/i1...i/IMG00032.jpg. this just broke off my car and i have not one clue what to do now. is that the Deflection pulley ?

You know im pretty sure thats the delfection pulley. You can partially see the part# of the protection cap thats still left on it, 11-28-1730.... which is the part # of the cap that goes on the delfection pulley..

#15 is the deflection pulley (offcenter bolt), #17 is the protection cap
http://www.realoem.com/bmw/diagrams/d/g/4.png

Take a look here for part #'s to match them up.
http://www.realoem.com/bmw/showparts...90&hg=11&fg=18

i cant get my fan off for some reason.:banghead:

This is a useful thread as I at my wits end with a squealing belt on the 2003 325i I am about to sell. For the last three winters it squeals on startup and three dealers have not been able to replicate the noise :confused:

In November they changed the v-belt and it still squeals
This week the hydraulic tensioner was changed and it made the problem worse :bawling:

This morning I had my wife start the car while I watched the belt. I can see it slip while the squeal is happening so am sure that is the source of the noise.

After about 5 dealer visits over the years I have decided to do some DIY and replace every possible part that could be at fault. What do you all recommend? Does anyone think cleaning the pulleys with alcohol or Emory cloth would help?

are the tensioner bolts reverse threads like the water pump? or to replace the tensioners I should just turn the bolts left to loosen? I just want to ensure that I dont snap any bolts when replacing the mechanical tensioner and deflection pulley on my car.

thanks!!

The deflection pulley falls off somtimes from the bearing seizing. Also, when replaceing the tensioner you might as well do the other as it will most likely fails soon after. The new hydraulic tensioner fixes the squeal caused by the mechanical tensioner, but you must remember the squeaks can come from multiple spots...Tensioner, Deflection pulley, alternator... Using along screwdriver and being very careful it is easy to diagnose these parts.

As far as the fan not coming off, there is a tool that holds the water pump pulley in place and the fan is easier to remove..in the case of the fan, it is righty loosy lefty tighty... reverse thread.

Torque spec help!
 

I am planning to change the deflection pulley and tensioner. Can anyone let me the proper torque specs for the bolts? The deflection pulley bolt is m10x150 and the tensioner bolts are m8x35. So far I am thinking that the torque spec is 40NM and 24NM???

Job done...Live and learn!
 

I just completed this diy and can now reply to my own posts in case any one has similar questions (which I doubt!!). Many thanks to the OP.

Bolts that hold the tensioner are NOT reverse thread. Left to loosen.

The m8x35 bolts for the mechanical tensioner should be torque to 24NM and the m10x150 bolt for the deflection pulley should be torque to 47NM. Once you find out the bolt diameter (i.e., m8, m10 etc) and the hardness factor which is stamped on the head of the bolt (8.8 for these bolts) then use the bolt tightening torque table in the bently manual (page 010-7).

This DIY is for the tensioner located next to the alternator, correct?

Is there a DIY out there for the A/C tensioner?

I recently replaced the Alternator tensioner, but now the A/C tensioner is squeaking.

I'm kind of confused on this. Mainly identifying which pulley is which and what terms are used for what, and I was hoping you guys could help me out. I've looked at a lot of pictures and parts trying to understand, which probably made it worse. =/ When you guys say tensioner (at least in this thread) you are referring to the pulleys which tighten the belts correct? So is this also referred to as a tensioner?
Also in the diy, it looks like there are 2 pulleys you have to take off, are those two separate parts/tensioners or is it just one? The dealer told me there are two and I assumed one was for the main belt drive and the other was for the a/c belt, but after seeing two pulleys removed here I wasn't sure. Also I know there are two types of mounting (centered and off-center) for a lot of the pulleys but which type will I need for each pulley? Lastly which pulley is the idler pulley?

anyone?

oh man, when I saw the thread title I thought this was for the seat belt tensioner, then I saw the first photos taking the fan cover off, and I was like 'damn, this is a serious job!!"


Then I realized it was the accessory belt tensioner....

Is there an easy way to know if you have a hydraulic or mechanical tensioner without getting down in there? I have 120k on my pullies and oddly none of them are making any sound as of yet. I am doing my water pump soon and figured I'd replace these as well.