69/70 Alternators 1100884 vs 1100825

[Michael B.]

Does the 1100884 have the same large front hole casting with thin bearing support stems that the 1100825 alternator has? These were used in the 1969/70 production years. I understand that both have the rear case fins over the internal regulator area.




[/IMG]

[Joe L.]

Re: 69/70 Alternators 1100884 vs 1100825

Mike----

Yes, the 1100884 alternator does have the "open face" design. However, the exact configuration of the drive end case may vary by when the alternator was manufactured. If it's a 1969-manufactured alternator, the case will have SIX thin ribs supporting the bearing. If it's a 1970-manufactured unit it may have either the 6 thin ribs OR it may have 5 slightly thicker ribs. In both cases, the design is "open faced", though.

Both the 1969 and 1970 split ring (rear) case halves do have the fin-type heat sinks. However, the 1969 and 1970 case halves are NOT the same (of course, there may have been some overlap, so I won't say what might have happened at the end of the 1969 model year or beginning of the 1970 model year). The 1969 split ring case has a grounding lug which is nearly flush with the rear of the case; the 1970 split ring case half has a grounding lug boss which rises about 1/4" off the rear of the case. Also, the 1970 split ring case half generally has a small, slightly raised rectangle beneath the "Delco Remy" script; the 1969 case lacks this nuance.

By the way, your photo did not come through for me, anyway. All I see is the "Red X".

[Michael B.]

Re: 69/70 Alternators 1100884 vs 1100825

I'll try to fix that 1st photo. I saw some of your earlier discussions on this topic and it has helped me from getting ripped off. I was looking at one but I have concluded it's a re-stamp of who knows what with a correct rear case. This one looks like a good front case to me.

[Michael B.]

Re: 69/70 Alternators 1100884 vs 1100825

Here's a picture of back of a 70 1100884.

[Michael B.]

Re: 69/70 Alternators 1100884 vs 1100825

This guy claims this is an original 1100884 but I don't buy it. Not the right pulley either.

[Michael B.]

Re: 69/70 Alternators 1100884 vs 1100825

And a photo of the stamping.

[Joe L.]

Re: 69/70 Alternators 1100884 vs 1100825

Mike-----

That's a 1970 split ring case half, for sure. It MAY have been used for very late 1969 and very early 1971, too.

Keep in mind that the alternator case half configuration is not absolutely "tied" to certain alternator part numbers. It just depends what case halves were being used as of the date that a particular alternator part number was actually manufactured. So, for example, an 1100884 alternator produced in, say, December 1969 might not have exactly the same configuration for the case halves as the same part number produced in, say, August, 1969.

[Joe L.]

Re: 69/70 Alternators 1100884 vs 1100825

Mike-----

This could not be an original GM #1100884 alternator. Even if it were a SERVICE 1100884, manufacture of that part number ceased prior to the time that the change from the "open" case to the "closed" case occurred and the 1100884 was discontinued from SERVICE in August, 1971. This unit has the "closed" drive end case configuration and, ergo, it could not be an original 1100884, either a PRODUCTION or SERVICE unit.

[Joe L.]

Re: 69/70 Alternators 1100884 vs 1100825

Mike------

Now you know what a bogus stamping on an alternator looks like. Among other things, notice the slight "slant" to the first "8".

[Joe L.]

Re: 69/70 Alternators 1100884 vs 1100825

Mike-----

From what I can see of it, this looks to be the correct drive end case.

[Mark #28455]

5 vs. 6 ribs

Are you positive about the 5 vs 6 ribs for 69 vs 70? I have been looking into this for some time now and have bought quite a number of front case halves. So far, every 6 rib one I have found has been blank (no part number stamping). I have even bought 2 or 3 that are midway between the open and closed design, one I remember was dated 1965? I can't get to my original 825 and 882 from my cars as they are in storage.

Mark

[Stephen B.]

Re: 69/70 Alternators 1100884 vs 1100825

Does the "OE2" mean "0" for 1970, "E" for May, and "2" for second week?

[Terry M.]

Re: 69/70 Alternators 1100884 vs 1100825

The 2 is for the second day. Complete date is May 2, 1970.

[Stephen B.]

Re: 69/70 Alternators 1100884 vs 1100825

My birthday. I was 2 years old. lol.

[Joe L.]

Re: 5 vs. 6 ribs

Mark-------

The attached photo shows an NOS GM #1100543 (1971 model year) alternator. This unit was manufactured on July 2, 1970. I would expect that any alternator manufactured at this time (and, who knows how long previous to this time?), regardless of alternator part number, would have used this same case half. I do think that most 1970 alternators had the 6 rib cases. However, I think that late 1970 probably used the 5 rib cases.

I agree that there is no embossed part number to be found on any of the "6 rib" drive end cases. I've looked for one for years and never found one.

I have never seen any that were of "full closed" design. The ones that I've seen are either "full open" (with 6 or 5 ribs) or "midway" (what I call "closed" design even though it's not full closed since there are no literally full closed drive end cases) with 5 ribs. The drive end case halves with "midway" design (what I called "closed") and 3 ribs are DN series drive end cases. However, they can be used with an SI-series alternator and many commercially rebuilt SI-series alternators may be so-equipped.