dshepp806

Not sure what happened here (exactly).....some history may be in order,....

She had an alternator/VR changeout a few years back,..I must say that I noticed (back then) that the engine pulley had a bend in it,..I was SO hoping that no one wrenched the pulley off with a frikin' prybar....it was only recently that I noticed what's revealed in the attached pics......GEEZE,...WTF!!!!!!!!!!!???????

I can say teh following:

We recently changed out both belts,..my helper, unfortunately, loaded the same shim arrangement back in (on the new belt install),..allowing for much play when he turned the ignition,...an obvious scraping sound ensued and engine was turned off.....one could easily see the scrape mark at the lower shroud shots....this is my fault for not having checked with him prior to iginition turn on,..tis a young fellow,..very interested in learning what's proper,....however, I had to remind him that the belt will tension more loosely with engine running,......subsequently requiring a tightening,..inanycase,...(mmm?)

We immediately postioned the proper shim positions and achieved proper belt tensions......I've then noticed the attached pics,..WTF? I must say that I DID NOT check the torque on the alt band piece...but certainly loosened upon my findings....looks like someone torqued the damned pulley to me.... (not me)

In the end this will need repair,....as it's very close to the belt, as is...........

I understand this to be of magnesium alloy and requires special process? Any suggestions, based on the provided pics?

GEEZE,..on thing after another,...

THANKS!

Doyle

dshepp806

Man,, that pulley's tweaked, for sure....

Doyle

rusnak

I'm lookin', but can't hardly see anything wrong. Most fan shrouds have far far worse "battle scars" than that. I'd just get the proper belt tension, check the fan blade clearance with a feeler gauge. Always give the fan a little spin before starting her up.

dshepp806

pulley has been bent a little,..shroud looks a bit bent, too,.....see the crack at the lower right bottom?

wildcat077

Doyle,

Just to be on the safe side,i would stop drill the end of the crack on the shroud with a 1/8 drill at the least...
That will ensure that the crack doesn't spread and elongate with the vibrations !
As for the pulley,if the belt runs true in the "V" groove then you shouldn't worry about it !

Cheers !
Phil

theiceman

yeah doesnt look serious at all to me .. if you take your eye away from the outer lip and just look at the groove your fine . groovey man ! look okay . I am sure that shroud can be touched up . I wouldnt worry about it too much.

500

Those magnesium fan shrouds on the Carreras can crack, but usually in the vanes. It is likely due to the heavier alternators (compared to earlier cars) and possibly exacerbated by incorrect belt tension

I would actually remove the shroud and separate it from the alternator/fan and get a complete picture of what you are dealing with. It may just be the crack on the flange that is already visible (and drilling the end of the crack is a sensible step), but there may be more. I would not want to run the fan with any scraping of the blades on the housing, as if those blades break off, it will make quite a mess (I saw pictures of where that happened).

Carrera51

To be safe, I would pull it and check for more cracks. When my 3.2 came out for a rebuild, my shroud had a crack that was visible, and several more you couldn't see when the motor was in the car. It's now a decoration in my office.

dshepp806

Thanks for the replies,..I think it time to remove and have a deep look......dammit.


Best!
Doyle

dshepp806

What did you use on the replacement?

Doyle

rusnak

Doyle, that crack is in a "good" place to have a crack. The material is thickest there, and not stressed like the vanes (esp the top vanes). Your shroud is sound. I'd leave it alone. The magenesium is very very porous just below the surface "crust", and it doesn't take well to being drilled or welded unless you want to get into using an argon hood to do the welding. If the crack bothers you, just put some JB Weld on it, and file it flush for cosmetic reasons. Once you start working on the magnesium, it's a very slippery slope indeed.

dshepp806

Good points, Rusnak. Thanks!

Doyle

whalebird

I agree that it looks minimal, but as 500 notes, to tight belt tension will damage the shroud at the vanes in the read; pulling the alt toward the crank pulley so to speak and breaking the support structure in the rear. This often manifests itself as fan/shroud contact. This can destroy your fan at bare minimum. I too have a 3.6 fan(12 blade) and shroud that will become a clock in the shop at some point.
Again, it doesn't look bad to me either, but may warrant some inspection if contact persists. The crank pulley will survive. A block of wood and a few taps with a hammer may replace it's approximate shape for now.
The fan belt will loosen up as it stretches. I leave these as loose as possible short of slipping.

dshepp806

Thanks, Bird.

I was speaking with a friend who spoke of trueing the pulley valleys (my words), if needed,..but they look quite straight, in terms of belt alignment. My concern is the proximaty of the cracked are to the belt.....I'm telling you, my dear friends, this wasn't there before..it just looks to be induced from a prying motion on the pulley (the bends....),..but I could be totally wrong..

Needs fixin'...I'm thinking of simply pounding it (softly) a bit to better that clearance to the belt (from where the shroud is obviously deformed)....

I checked the fan a bit further this evening and noted nothing of remarkable mention......fan looks to be in tact, especially at the crucial joints....again: best I can tell,..and I stared at it for a long time.....even had the maginfyer out!!!!!!!!


Bird,..as to belt tension,....I've long heard the old schoolers say the same,..leaning more towards a degree of "looseness" on the V-belt. I realize that the manual specs a degree of deflection, at mid point...,..I've often reached down and attempted turning of fan (CW) to see if I've slack or not.....somehow reaching an acceptable tension, especially AFTER that belt settles to it's resting position........

Thanks for the comments.

Doyle

dshepp806

Just to rehash (again) the photos:

#1: shows pulley's bend....as well as crack in shroud. (as well as bend in the shroud)

#2: upper right side crack, as well as lower..

#3: same as #1

#4: lwr right carck

#5: pulley laterations

#6: more pulley bends and shroud cracks.

#7: bends,..cracks,..shroud area..

(geeze)....

Maybe I will take the JB weld coating approach, once I knock the offensive piece (near the belt) backwards towards the shroud...

WTF?

Thanks.

Doyle