New 1993 525i (M50) Belts / Pulleys

[uscharalph]

Just bought a 1993 525i (M50). It has 149,000 miles on it. I'll post pictures later.

I'm getting a part order together and am replacing the 2 serpentine belts and the pulleys? / idlers? / tensioners? I see there is a mechanical and hydraulic version of the system? How do I tell which I have?

After verifying which I have, does anyone have a parts list for me?

[whiskychaser]

I see there is a mechanical and hydraulic version of the system? How do I tell which I have?

The hydraulic one has a mini shock absorber on it:
http://www.realoem.com/bmw/showparts...44&hg=11&fg=18

[uscharalph]

Here's a couple of pictures:

[uscharalph]

Apon a very quick inspection this morning (B4 work) it looks like I have the hydraulic version.

[Rus]

The A/C unit is hydraulic. To see if you have the hydraulic main belt tensioner, look around the alternator area for something with a hydraulic shock.

[uscharalph]

The A/C unit is hydraulic. To see if you have the hydraulic main belt tensioner, look around the alternator area for something with a hydraulic shock.

The A/C is the one I saw. Looks like I need to inspect for the other.

[russiankid]

When you replace the tensioner on the A/C, or even release the tension from the belt, be extra careful. DO NOT pry on the shock on any mounting points. The best way and safe way I have found is to take a ratchet with a socket, and put it on either the top or bottom bolt(forgot witch, I think it was top) of the shock and turn the bolt clock wise. This will not damage the shock, you will have much better leverage than prying, and takes 30 seconds to slip the belt on.

Its a good idea to replace the pulleys. The hydraulic tensioner on the alternator uses the same pulley as the A/C belt does. If you have a mechanical, you will need to order a new tensioner. There is also an idler pulley on the alternator, which should be replaced.

[xspeedy]

There are two belts, three pulleys, and two tensioners. Replace all of them. The tensioner for the main belt is hidden behind the lower pulley, so you'll need to really look for it. As was mentioned, the hydraulic version looks like a really short stubby shock/damper/strut.

[uscharalph]

So here's what I've ordered so far:

11281738991 - A/C Serpentine Belt
11281748131 - A/C Idler Pulley (2 Total - Same part # on Alternator/PS Belt)
11281437929 - Serpentine Belt for Alternator/PS (May Be Part # 11281469266)
11281748131 - Alternator/PS Idler Pulley (2 Total - Same part # on A/C)
11287841228 - Alternator/PS Deflection Pulley
11281727159 - Pulley Protection Dust Caps (3 - 1 for each Pulley)

I'm holding off on the Hydraulic shocks / tensioners til we see what's going on there

[dreman77]

So here's what I've ordered so far:

11281738991 - A/C Serpentine Belt
11281748131 - A/C Idler Pulley (2 Total - Same part # on Alternator/PS Belt)
11281437929 - Serpentine Belt for Alternator/PS (May Be Part # 11281469266)
11281748131 - Alternator/PS Idler Pulley (2 Total - Same part # on A/C)
11287841228 - Alternator/PS Deflection Pulley
11281727159 - Pulley Protection Dust Caps (3 - 1 for each Pulley)

I'm holding off on the Hydraulic shocks / tensioners til we see what's going on there

Hi,
can tensioners be re-adjusted or of a tensioner os nt working right, you just replace it. I am looking to replace both my belts this weekend and was wondering if i should change the tensioners too?

thanks