Alternator mounting bolts

[poohbah]

Does anyone know the type/size/length of the alternator mounting bolts for 116 GTV 2.0L?

Was happily cruising along freeway today, when all of a sudden heard a small clunk then a high pitched metallic whine when revs dropped below 2500rpm. Pulled over and found the top left alternator mounting bolt (looking toward cabin, so the one nearest water pump pulley) had disappeared. Best i could do on the fly was wrap a smaller bolt in leccy tape and bung it in to get the car the 5mins to home, but the whine continued. It seems the alternator fan is justly slightly clipping on one of the bolt heads on the bracket.

Had to get to an appointment so couldn't a decent look til after dark. Seems one potential tricky bit is fitting the bolt head past the water pump pulley? Any clues - or is it simply that the right size bolt will have a head small enough to fit past the pulley?

Alternator also seems to have a fair bit of play backwards/forwards as well as laterally - couldn't see if there is more than one bolt missing.

[poohbah]

Thanks Sportiva - that would explain things!

I am a bit puzzled how it came out if there were two threaded parts - one in the block and the other part going through the bracket.

The stud doesn't appear to have broken off in the block (thankfully) because I was able to bung a skinny bolt in just to get the car home. I guess the nut on outside must have worked loose, and then the stud worked its way out too. Sounds slightly unusual.

Will see if I can source the correct bits from the workshop.

[bazzbazz]

I am a bit puzzled how it came out if there were two threaded parts - one in the block and the other part going through the bracket.

The stud doesn't appear to have broken off in the block (thankfully) because I was able to bung a skinny bolt in just to get the car home. I guess the nut on outside must have worked loose, and then the stud worked its way out too. Sounds slightly unusual.

You're supposed to say "Amen" for small mercy's. 

[rowan_bris]

The stud isn't in the block.  It is in the water pump and it is 8mm

[poohbah]

Cheers Rowan - I have now sourced the correct stud from workshop and yep, it goes into the water pump not the block.

[poohbah]

All good Sportiva - there is only one hole it can go in!

[alanm]

I just had the same stud fail in a Bugatti brand water pump that was only about 1 year old.
My car is a 75 TS but the part is the same. Coincidence?
Al

[poohbah]

I'm guessing the answer is no. Guy in the workshop told me they do it from time to time. Sounds like a good old design flaw...

[LukeC]

Quite often, people don't tighten the lower 12 mm bolt enough... Just making it snug so you can adjust the tension on the alternator without loosening it. Make it nice and tight! A hassle for adjusting the belt, but guards against this happening. If it  has been rattling around for a while the timing case alternator interface will be worn and the alternator may not sit square.

[poohbah]

Good tip Luke.

[alanm]

Yes, good tip, I'm going to double check that the lower bolt is tight.
The nut on the rear is difficult to get at...
Al

[poohbah]

I have now screwed it all back together. The clattering was down to one of the skinny bolts holding the drive-end bracket of alternator to the end cover winding its way out and just getting clipped by the alternator fan.

[poohbah]

Further tinkering - after alternator was all working properly again, I noticed annoying noise from one of the AC pulleys - worn bearing - so I removed it initially with the intention of replacing. But - as AC has never worked anyway (and inlet pipe cracked ages ago so no gas in system either) just kept going and removed the compressor and mount. Oh the joy of clear access to the front and exhaust side of the engine...

And boy the compressor and mount were heavy - I may be imagining any noticeable difference, but it does seem as though the front end feels a little lighter, as does low speed steering.