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-   -   What is the correct alternator, fan belt assembly order? (https://rennlist.com/forums/964-forum/1115581-what-is-the-correct-alternator-fan-belt-assembly-order.html)

5hrine 11-29-2018 10:55 AM

What is the correct alternator, fan belt assembly order?
 
Having looked through all the posts I can find on the alternator/fan pulley assembly, I have a couple of queries which I hope can be answered. I have a 964 with a 92 motor and there have been some belt issues. P.O told me the alternator has just been renewed ( have receipt) But battery is not charging at idle and low revs, only above about 3000 and there is a nasty metallic rattle from the fan area and alternator belt seems a little slack. Having taken all the pulley shims etc. off, I notice only 2 fan shims, with no extras stacked outside the pulley, So will add extra 4 to get correct thickness. There are threaded studs into the fan, rather than a threaded hole for bolts . (I dont think this should matter) then the outer pulley cone washer, I always assumed that the taper faced the front of the car, so the washer sort of sits a bit inside the fan, this way it allows the fan bearing to spin, but if the fan pulley shims had been missing (which they were) the cone washer would probably bind on the fan bearing causing the metallic sound and presumably may not allow the alternator to spin freely, therefore limiting the charging to above 3000. Outer shims seem okay and there are a total of 6 (2 in and 4 out of the pulley). there was also a final washer before the nut ( which I assume was making up for the lack of 4 fan pulley shims) What I am trying to find out , is, am I correct in the number of shims, position of the cone washers and the threaded studs being okay, or have I missed something critical. I wanted to reassemble everything correctly and see if the charging/noise issues had been resolved, before pulling the alternator, fan bearing etc. any help would be greatly appreciated. Cheers

Rocket Rob 11-29-2018 11:44 AM

How tight are the belts? You remove shims to tighten. Any unused shims get stored on the outside of the pulley, The belt closest to the engine (most forward) drives the alternator. If you remove all shims, does the belt tighten up? If yes, store the extra shims on the rearward face of the pulley.

The rearward belt is the fan drive. You do the same process.

Do you have PET? There is a drawing of the sequence on 105-00.

5hrine 11-29-2018 12:09 PM


Originally Posted by Rocket Rob (Post 15462912)
How tight are the belts? You remove shims to tighten. Any unused shims get stored on the outside of the pulley, The belt closest to the engine (most forward) drives the alternator. If you remove all shims, does the belt tighten up? If yes, store the extra shims on the rearward face of the pulley.

The rearward belt is the fan drive. You do the same process.

Do you have PET? There is a drawing of the sequence on 105-00.

I have PET and have got the shim/pully/tightness sorted. It was really more about the threaded studs instead of the bolts into the fan and the position of the inner cone washer between the two pully's. I thought facing the bfront of the car, but hard to see looking at PET.

Rocket Rob 11-29-2018 12:15 PM

The cone washer flat side supports the pulley.

5hrine 11-29-2018 12:23 PM


Originally Posted by Rocket Rob (Post 15462999)
The cone washer flat side supports the pulley.

Thats what I thought, but the cone washer i removed was scored from something (bearing housing?) so I hoped that by adding back the correct shims this may help, but the shims on the fan rotor do not space the cone washer out, so it may still be rubbing. This does not seem correct to me. ?!?

5hrine 11-30-2018 07:39 AM

All assembled now, removed 1 shim from the alt. belt and alternator is charging okay, but it defiantly sounds as if the fan bearing is in its way out. One step forward....


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