fiatrn

Last fall, my 928 ate the alternator shroud. One day, it was simply gone when I peeked under the car.

It was always fastened mostly with luck - the studs sticking out of the back were too short and partly stripped, so that the small M5 nuts would barely grip, and only on two of the four studs. Still, with how tight the wiring plug fit, I figured it was safe. Wrong! And gone without any drama. I never heard or felt anything.

Today, i appear too have solved this problem. Searching around Rennlist, I could not find any other solutions - so if someone else solved this, I apologize for the repost.

And I apologize that i can't swear by which alternator the car has. The factory shroud fits perfectly, so I assume I have the proper alternator for my car ("late" USA 1986 5.0 / 1986.5 S3). In the large bundle of paperwork that came with the car, there is no evidence that the previous owner had to replace the alternator. I purchased a used shroud from 928Int.

There are four "through" bolts that hold the main body of the alternator together. They are insterted from the front, and the heads of the bolts sit in small cutouts so that they are flush with the face of the alternator. The heads are slotted cheese heads (horrible). The bolts are nominally M5 bolts*. The ones in my alternator were about 110mm long - just barely too short. After some online searching and being unsure, I went to the metric guru in Denver. He sold me M5 x 120mm socket head screws , bc the ones I brought with me don't exist in normal manufacture - they are basically proprietary to alternators!

M5 x 120 bolts are available online, but I needed advice and didn't feel like waiting for shipping. I paid 5$ for 4 bolts and good advice.

The socket heads are very thin, and do NOT stick out past the face of the alternator. The slight extra length gives me enough room on the rear to mount a split washer and a nut and have a few threads sticking out.

One rennlist thread I found voiced some consternation on mounting the alternator and shroud. Mounting the shroud onto an installed alternator would take an act of heroics, coupled with luck, and probably close proximity to a black hole to bend space time. NdGT would be impressed.

I can not bend space time under my Porsche, so here is what I did:

(note, I do not have the stock fan shroud, my car has been converted to dual electric fans)
(also note, my car is on jack stands, not a lift)
(also also, I Am left handed)

I placed the alternator on a paint can, bc that seemed a nice height
I hooked up the wiring to the rear, with a neat little turn to exit the shroud
then I hooked the shroud onto the alternator
next, I lifted the alternator into position
insert the lower bolt that holds the adjuster in place, thread a little
slide belt in place
(doing this gave enough holding power that I did not have to hold the alternator over my head)
push the lower radiator hose out of the way with left hand
slide the upper pivot bolt into the front of the alternator with right hand (contortionism)
(make sure the washer is near the alternator, NOT near the head of the bolt -
or it will catch the hose even worse and make you curse)
now with right arm, heft/wiggle/align alternator upper pivot
at the same time - with left arm, wiggle the pivot bolt until it goes into the mount
(this may take a few tries - or a few more tries)
once it is in the mount, continue wiggling the alternator while you press the bolt in by hand
when the bolt hits the rear of the alternator, you will need to thread it
(I could NOT get a ratchet to fit between the radiator hose and the bolt head,
but a 17mm combination wrench fit just fine, though it was a little ponderous)
almost tighten everything, set belt tension, then tighten the pivot bolt and the lower mount bolt
re-connect battery
start car, whoop with joy





M5 x 110 cheese head OE alternator bolt on left M5 x 120 socket head on right. heads are almost the same depth








balance on paint can (technical!), cowl almost in place




longer bolts give plenty of room for split washer and nut. m5, of course.



(the metric guru said they are actually closer to M4 diameter, and the threads are rolled instead of cut, so they act as M5 and fit M5 fasteners. He also said that the stock bolts are very similar to ones used to hold some microwave ovens in place, and if I insisted on originality, I should try the appliance parts store. I did not insist).