Alternator housing orientation?

[Chris E.]

Do I have the alternator right? Someone mentioned that the back half housing might be out of phase. In other words, the back half of the alternator might be bolted up to the front half incorrectly.

Thoughts?

I looked at some other pictures of high Top Flight cars that I have saved, and those are the same as mine.

[Bill I.]

Re: Alternator housing orientation?

Chris, looks right to me. BUT, what kind of throttle return spring is that? That not right. Bill.

[Jack H.]

Re: Alternator housing orientation?

Typically, the difference in PN's on alternators flow from: (1) specific pulley/fan, (2) rated amperage output, and (3) assembly 'clocking'. In the last vein, it's possible to orient the rear case to the front case in several different ways.

Next, just because this/that car has earned this/that award, doesn't mean everything you see/photograph is factory concours correct...

The rear case half has a 'flat' on it. For Corvette, that flat was typically oriented such that it was facing the adjacent cylinder head/valve cover. That provided maximum alterator 'adjustment' on the upper swing arm without touching/scraping against the valve cover.

I'd agree with the comments of others, yours is 'clocked' 90-degrees off.

[Rick S.]

Re: Alternator housing orientation?

Chris,
Who did the rebuild of your alternator? Yours looks like mine and John Pirkle did my rebuild.
Rick

[Chris E.]

Re: Alternator housing orientation?

I think mine is a Pirkle rebuild as well. I'll have to get it fixed.

Is that something I can do myself? Seems to me I ought to be able to just pop the cover off, move it 90 degrees, and put it back on. Thoughts?

[John C.]

Re: Alternator housing orientation?

Chris

I believe yours is correct the way it is. You have the flat oriented to the valve cover. I wouldn't change it.

John

[Louis T.]

Re: Alternator housing orientation?

Chris,



Louis

[Michael H.]

Re: Alternator housing orientation?

Do I have the alternator right?

There are several excellent GM pictures of new 66 and 67 engines in the Noland Adams book and all show the alt clocking the same as the one in your picture.

I think you may need to repaint the stator in yours, though. (the part showing between the front and rear housings) It appears to be something other than black?

[Wayne M.]

Re: Alternator housing orientation?

....I think you may need to repaint the stator in yours, though. (the part showing between the front and rear housings) It appears to be something other than black?

I just about choked on my morning coffee .

[Wayne M.]

Re: Alternator housing orientation?

OK guys --- now that I've checked my stator laminations, I have a few C2 alternator drive-end / comutator end clocking, and other comments.

Yes, the rear half (CE) is usually clocked 90 degrees to the right of the front half (DE), putting the grey R/F plug to the right of the top brace mounting tab. But going through my old road tests from 1963, I see only the plug in vertical alignment with the brace tab, which confirms Pirkle's description [and probably the '63/4 TIM&JG as well].

For BB's with Power Steering, the entire alternator is rotated 90 degrees left (viewed from the driver seat); probably because of the complex mounting brackets. The DE/CE clocking of the halves is still the same as '64-7.

(to Jack H.) -- your 3rd para. reasoning about the "flat" facing the adjacent cylinder head applies only to '64-5 C60 cars and '66-7 (all SB, and BB w/o N40). For other '64-5's with passenger side alternators, the grey plug faces the inner fender.

[Jack H.]

Re: Alternator housing orientation?

Please re-read my post, paying attention to the English disclaimer 'typically'...

[Jack H.]

Re: Alternator housing orientation?

Yes, you can re-orient the alternator's rear case by yourself, but you have to pay attention to detail. Inside, the brushes are installed in spring loaded holders to press them against their mating rotor contacts.

If you remove the case bolts and let the rear half of the case move rearward too far, the brushes will 'pop' off their rotor contact rings and then you won't be able to push the rear case fully forward onto the front case. That typically generates a 'foul language' session...

BUT, the assembly method IS defined in the service manual and tells you to install the brush into its spring loaded holder, and 'peg' it in place using a paper clip (or similar tool) while you slide the rear case home and install the case bolts. Once, the bolts are installed, you remove the paper clip and let the brushes 'snap' home against their rotor contacts.

So, if you understand this aspect of the alternator AND you're careful to hold the rear case CLOSELY against the front half, it IS possible to simply rotate the rear relative to the front and re-install the case bolts without having to fully separate the case halves, re-insert the brushes and use a holding tool (e.g. paper clip)...

[Michael H.]

Re: Alternator housing orientation?

Yes, the rear half (CE) is usually clocked 90 degrees to the right of the front half (DE), putting the grey R/F plug to the right of the top brace mounting tab. But going through my old road tests from 1963, I see only the plug in vertical alignment with the brace tab, which confirms Pirkle's description [and probably the '63/4 TIM&JG as well].

Yup, I agree. I think alternators for 63 were unique as the vents on the rear housing were in line with the adjusting boss on the front housing. I think all were rotated 90* for 64 and later??

I helped a friend here a few months ago rotate/correct the clock position of a recently restored alternator. Also wanted to change the color of the exposed stator ribs from caramel to black, the way they should be.
Unfortunately, what ever was used to coat the stator in the caramel color, bonded the case halves to the stator. It was almost impossible to separate the halves without damaging the case halves. Finally got it apart though.
Had to chip all of the caramel coating off so the individual plates of the stator showed once it was painted black. Was a three hour ordeal!

[Jack H.]

Re: Alternator housing orientation?

Interesting!

You, of course, know there was a LONG time difference of opiniion between John Pirkle and others in the alternator restoration business on the 'correct' color of the exposed 'rib' section of the stator...

It was John's opinion that they were all carmel color shellac coated and those we see that are black got that way because time/temperature 'aged' and discolored the original shellac. I was tempted to re-do the '696 on my '396 to remove the black, but stood my ground and simply lived with the minor deductions various judges took for it being black when I campaigned the car...

I've always wondered if now that we know more about the 'cosmetic' black being factory original, John is providing 'warranty service' to the hundreds/thousands of his prior customers...

[Chris E.]

Re: Alternator housing orientation?

Yes, you can re-orient the alternator's rear case by yourself, but you have to pay attention to detail. Inside, the brushes are installed in spring loaded holders to press them against their mating rotor contacts.

If you remove the case bolts and let the rear half of the case move rearward too far, the brushes will 'pop' off their rotor contact rings and then you won't be able to push the rear case fully forward onto the front case. That typically generates a 'foul language' session...

BUT, the assembly method IS defined in the service manual and tells you to install the brush into its spring loaded holder, and 'peg' it in place using a paper clip (or similar tool) while you slide the rear case home and install the case bolts. Once, the bolts are installed, you remove the paper clip and let the brushes 'snap' home against their rotor contacts.

So, if you understand this aspect of the alternator AND you're careful to hold the rear case CLOSELY against the front half, it IS possible to simply rotate the rear relative to the front and re-install the case bolts without having to fully separate the case halves, re-insert the brushes and use a holding tool (e.g. paper clip)...

Thanks Jack for a very thorough description of what I'm NOT going to do.....yup, that is more than I want to risk with a freshly rebuilt alternator.

Much appreciated.