So, I put the new alternator in and install the fan back in it's housing. Fan spins free with no issues.

Then I put it in the shroud and tighten up the strap around the alt stand.

When I run the motor it makes a horrid scraping sound and metal shavings are a flying.

Why? Help me.

KT

Did you align the alternator fan housing with the roll pin (dowel) on the engine case? If you didn't, you'll squeeze the housing out of round. Good luck, Don

No. I didn't... <_<

Now what?

KT

fix it by locating the hole and the dowel??


at least I'm not the only one today getting their blood pressure going higher by working on the teener

Pull it out again, I know, damn. Look for the slot on the outside of the fan housing. Check for the roll pin in the engine case. Mark the housing with a magic marker 180 degrees from the slot, the mark will be on the top of the housing when it's installed right. Put the alternator back in, wiggle it onto the pin. Install the strap, and test run.

Is it the same fan that was in the housing?

Sometimes a new fan will do this. It freaked me out the first time I saw (and heard) this happen, but apparently others have seen it more often. IF you are SURE everything is installed correctly, run the engine for a few seconds (20 or 30) and the fan will "clearance" the housing. It is probably only interfering a few thousandths and will quiet down. If it does not quiet down after 20 or 30 seconds, you may have bad or very poor bearings in that alternator allowing the fan to float around...

I wish you the best of luck.

(just my 0.02)

Same fan, new alt.

Was smooth turning until I tightend the strap.

I don't know how it could be off. It only goes in one way. The bolt holes only fit in the shroud one way.

KT

I am soo gonna contact you Don when my finals are over and the six is getting put in. I didn't even know about what yall are talking about.

Trekkor,

just wondering.....is the metal shim in place behind the fan, on the crankshaft? I'm not sure if the fan would touch the housing when there's no shim in place.

If you're gonna pull the housing out again, take a close look at the fan opening area and look for the scuffed surface and go from there.....if the back of the housing is rubbing, maybe it's the missing shim that should have been been there....if the markings are on the front of the fan housing, umm dowel pin on the fan hub? dowel pin on the housing to case?

hope this helps....

jerry

Ohhhh wait!!!

I re-read your first message....

you're running a six cylinder engine? What I had mentioned above, that was for the 4 cyl. engine....

on the six, that would be strange....unless the alternator isn't sitting in position correctly....that would too obvious as the fan blades would be sticking out in funny way....

what are you running now? 6? 4?

j

Jerry,
I'm running the SIX on the bench.

the sound is awful and it won't go away.

KT

If the alternator locating slot is not aligned with the roll pin, the alternator fan housing will not sit on the saddle properly and will be cocked, as you tighten down the strap, the roll pin will dig into the fan housing, causing it to go out of round, and then the fan blades will contact the housing, metal shavings and a unbalanced fan will result. At 7000 rpm a unbalanced fan is not a good thing.

It is posiible to overtighten the band , try backing the strap bolts off at little bit . alsc the nuts on the ailternator to the housing are tight , right .And the belt is shimned correctly?

[FONT=Arial]Okay....

from reading your other message about the voltage reading...it made me wonder if the alternator internals are chewing up?

were you able to spin the fan (without the belt) freely and no noise?

if there's noise, try rock the fan up and down, side to side to see if there's any cocky movement....if so, that's a big NO NO...your alt bearings are more likely shot...

If there's no sign of rocking movement, then start turn the fan a rotation at a time to catch the scuffing or scrapping sound, then stop right there....back up a bit, go forward again till you trace the sound source, then let me know where you find it.....we go from there....it's hard for me to help you out without seeing the actual fan assembly....

by the way, is the engine an original 2.0L 9146? the timing chain cover looks very 'vintage'! Especially the left one when looking at the engine, the cover has a provision for mechanical fuel pump back then when running the zenith carbs....Not the MFI as everyone knows but way before that, there used to be a mech. pump there.....I hope I'm right on that as it's been a long while I've seen that type of engine...

j

Is that picture how it looks as you are "bench" running it?

If so, can you remove the fan belt and just verify that it is indeed the fan causing the noise.

If it is the fan, and you have the belt off, does the sound happen when there is no belt (spinning the fan by hand)?

Since it is out of the car and very visible, I would (with the belt off) get a flashlight and turn the fan by hand and watch where the fan is contacting the housing.

Is the alternator IDENTICAL to the old alternator or is it an updated alternator.

Is there any radial play in the alternator bearings? Can you press the fan and make it contact the housing?

How tight did you tighten the strap? It does not need to be so tight that it deforms the fan housing.

If it is the same fan and housing and the alternator is installed into the housing so that the fan does not rub, and the alternator bearings are good, the fan should not rub unless:

1. The housing strap is so tight that it deforms the housing.

2. The belt tension is so great that the fan contacts the housing at the bottom. (The fan belt should be snug, not so tight that you can't deflect it by at least 1/2" between the pulleys).

I hope you get this worked out in the very near future.......... (I can almost hear it)

What Don said. The fan housing is being deformed.
I think it should read....fan housing locator slot , not "alternator locating slot"
There is a timing mark on the housing....a cast in line. It should line up with the case seam...or damn close.

I've likely overtighted it.

The fan spun silently and smooth until I came along.

This is a replacement, updated unit.

Now what?

KT

Yup, you got me, so I looked it up, fan housing is the right name. lol

Short hijack, Dr Evil, went for a walk the other day up 35th st, didn't see any 914's, you did say you were on 35th didn't you? Or is my CRS acting up again. What's that old saying, of all the things I miss, I miss my mind the most . Take Care all, Don

Is the fan rubbing in the housing ? Or is it rubbing on the face off the altenator, Is the spacer on the shaft behind the fan ?
if not it will go on to far and rub. Watching spiderman 2

Just got done watchin' that....wanna know how it ends?

Short Hijack reply:
Don,
I live on 35th, but the cars are in my back yard and all you would see is the shape through a blue tarp, and one orange one partially exposed. My house has a tarped motorcycle on the side of the porch on the sidewalk. I just wanted to let you know that I wasn't ignoring you, just busy with school.
Hijack concluded.

KT,
I'll bet if you find a surface that is tough and concentric you can re-true your housing if it was warped. The only hard part would likely be finding such a surface, but I bet you could.

Is that your bench testing exaust? That would look really weird sticking up out of a 914!! I agree with removing the belt and checking your clearances. Not running it 30sec to grind it's way fixed?? As someone else said that could throw out the blade's balance. Wish that motor was going in my car a 72/914/1.7L. Good luck with it.

That's what I thought the first time I experienced fan-housing interference. I was observing after a fan swap and there was HORRABLE noise eminating from the fan contacting the housing.

The mechanic said that this sometimes happens when a new fan is slightly larger than the old fan. The car was run and the engine was revved a few times and the fan clearanced itself in a very short time. I asked about the balance issue, but was told that the fan blades were harder than the housing so the housing was worn away at the point of contact.

They assured me that this is sometimes the case when changing fans (and I trust them). I am only assuming that there is some manufacturing tolerances in the alternator mount and when bolting it up to the fan housing, if it is slightly off, it may rub as a new fan could.

The housing is a fairly soft material and will wear quickly. If the noise does not dissipate with running for say 30 sec, there is something else interfering.

Without seeing the car or seeing where the interference is, it is hard to determine where the problem is.

I suggest that if the problem is not found easily, the fan/alternator be removed again to insure everything is installed correctly and to identify exactly where the interference is before going too much further. The interference should be easily identifiable as bright freshly ground areas.

OK, that was wierd...we were all watching Spiderman 2 last night?

Anyway, It sounds like the fan is rubbing the alt.
Not the blades on the housing. I say this because I can't find any rub marks in the housing surface.

Pics later...

KT

then DON'T run it ...

Andy

I'm back. All is not lost.
Broke it down again. The inside of the fan body is just tickling the face of the alt'n'r.

I think a 1/16" thick washer cures all!

pics for your pleasure.

KT

If that is the case, then I would agree with SIXNOTFOUR:



You will need to remove the fan from the alternator and install the spacer so that the fan won't contact the front of the alternator.

Here is the alt'n'r face.

Just a close shave

The fan blades are fine and the housing is true.
When I bumped the fan a scoatch off the alt'n'r it spin silent once again.

KT

You guys are the best...

Thanks for the help!

Here'e the locating pin Don mentioned on the alt'n'r stand.

KT