L-84 Alternator Misalignment

[Doug L.]

hi guys,
When I attached my alternator last night I noticed that it doesn't align with the pulley. I had the alternator rebuilt. It is the correct part number and date for my 1964 L-84 and as far as I know is the original. I didn't pay attention to the pully when I sent it to be rebuilt.

In a December 2010 thread there was a discussion about a similar problem on a 1963 SHP. The user had a pulley that had uniform "blades" on the alternator fan and his solution was to buy the correct pulley with varied blades.

My pulley fan has varied blades but doen't have the same stamped pattern on its face as the one shown in the December thread. The pattern wouldn't have anything to do with the alignment but may indicate that this is not the correct fan. But the spacing between the fan and alternator case seems to be the same as the unit shown in December. My engine did have an incorrect crankshaft damper which has now been changed to the correct NOS finned unit. The double crankshaft pulley that was used with the incorrect damper is on the finned damper now. Could that be the cause? I will appreciate any help.

Thanks-Doug

[Wayne M.]

Re: L-84 Alternator Misalignment

Doug -- you have the wrong pulley/fan for a '64 FI. Should be a separate fan and pulley -- yours looks like an integral fan. And the multiple ribs on the fan blades are way too late (ie. after '66 ?) for a '64. You might have been given a different fan-pulley than the one you sent in .

Another point; you restorer painted the stator lamination ribs (between the case halves) a gaudy orange --- srictly a no-no.

Pic below is of a late '65, but pulley should appear the same as for your '64 L84; and would probably cure that mis-alignment.

[Joe L.]

Re: L-84 Alternator Misalignment

Doug -- you have the wrong pulley/fan for a '64 FI. Should be a separate fan and pulley -- yours looks like an integral fan. And the multiple ribs on the fan blades are way too late (ie. after '66 ?) for a '64. You might have been given a different fan-pulley than the one you sent in .

Another point; you restorer painted the stator lamination ribs (between the case halves) a gaudy orange --- srictly a no-no.

Pic below is of a late '65, but pulley should appear the same as for your '64 L84; and would probably cure that mis-alignment.

Doug and Wayne-----


The pulley and fan pictured in Doug's photos may or may not be a pulley with integral fan. However, either way, it's the wrong one for the application. The correct pulley is a GM #3829193 which is a 3-5/8" machined steel pulley configured like the one in Wayne's photo.

[Doug L.]

Re: L-84 Alternator Misalignment

Wayne, Joe, thanks very much. Wayne's photo makes it clear that I have the wrong fan and pulley. If I could pick your brains a little more, I'm wondering what to do about the laminations between the 2 halves of the case. I assume the pulley and fan will come off the shaft easily enough but I don't want to separate the case. I couldn't find anyone local who rebuilt alternators so it went to Ohio for the overhaul. I don't want to send it back there just for the laminations and change of fan/pulley when I locate them.

The color of the laminations that appears in the photo I posted is much brighter in the flash of the camera than it actually is. In normal light it is sort of a gloss rust color. In the photo it appears almost the same as the GM orange paint on the engine. Can I get away with painting these laminations wth a flat "caramel" color as stated in the JG? I also understand from the JG that the pulley is a natural finish casting (un-painted).

Thanks again. Doug

[Stuart F.]

Re: L-84 Alternator Misalignment

Doug;

It is a common ploy for alternator rebuilders to return an SHP alternator with a lower HP fan and pulley. That was tried on me too by Chicago Corvette many years back. They assume we don't know anything about pulleys, and specially the value and rarety of the SHP parts. They take a chance for which they can always plead innocent by virtue of their own ignorance. Get back to them and demand they return the correct pulley and fan!

As to whether they are easy to take off and put back on, well, the simple answer is NO! The SHP pulley has a deep set nut on the shaft which is hard to get a grip on with normal tools, and keeping the rotor from turning is another task. Rebuilders have the necessary tools and I strongly recommend you job it out to some one with experience and the correct tools. If you try to do it makeshift you may mess it up good, and you'll swear a lot.

Stu Fox

[Doug L.]

Re: L-84 Alternator Misalignment

Hi Stu,
Thanks for your input.

I took a look at the alternator this afternoon. The shaft has a hex-key opening in its center, presumably to allow the shaft to be held while the nut is removed. However I coldn't budge the nut and stopped before I messed it up. I agree that I need to have the work done by a pro. But
I have the same problem getting the pulley and fan off that I had getting it rebuilt. I find no shop in S. Florida that does rebuilding. There is an electric motor repair shop nearby so I'm going to ask them if they can preform this simple mechanical task. If I can get someone to remove the incorrect fan and pulley I should be able to get them to install the correct parts when I have them.
Doug

[Stuart F.]

Re: L-84 Alternator Misalignment

Doug;

Ah yes, it's coming back to me now. Now you know what I meant about special tools. You probably need a socket to fit the nut, and that socket has to have a hex drive end so you can get a wrench on it while holding the shaft with an allen head wrench thru the socket. Needless to say, you would need to hold the alternator (protected) securely in a vice in order to get the proper amount of leverage with the wrenches. Torquing the nut back on would be fun too.

Best find a pro, as you said. Perhaps watching them do it would be wise as well to make sure they know what they are doing and don't mess it up more than you or I would do.

Stu Fox

[Joe L.]

Re: L-84 Alternator Misalignment

Hi Stu,
Thanks for your input.

I took a look at the alternator this afternoon. The shaft has a hex-key opening in its center, presumably to allow the shaft to be held while the nut is removed. However I coldn't budge the nut and stopped before I messed it up. I agree that I need to have the work done by a pro. But
I have the same problem getting the pulley and fan off that I had getting it rebuilt. I find no shop in S. Florida that does rebuilding. There is an electric motor repair shop nearby so I'm going to ask them if they can preform this simple mechanical task. If I can get someone to remove the incorrect fan and pulley I should be able to get them to install the correct parts when I have them.
Doug

Doug-----


A hex (allen) drive socket will retain the shaft. Use a high offset box wrench for the retaining nut.

I think you'll be able to coat the exposed stator ring using the appropriate coating (whether it's supposed to be caramel-colored or black I'm not going to get into) and a small artists brush. I'd carefully mask off the case halves adjoining the stator before applying the coating. This should be very easy to do.

[Jim L.]

Re: L-84 Alternator Misalignment

Another, and in my opinion easier, way to R&R the fan and pulley is to use an impact wrench and a socket. The inertia of the armature is sufficient to keep it from turning (much) while the hammer blows from the impact wrench loosen and then tighten the nut. Done it many times.

Jim

[David L.]

Re: L-84 Alternator Misalignment

Doug,

Enclosed are 2 photos of sketches of a 3829193 alternator pulley that I drew back in the 1980's. I believe that I probably sold the pulley years ago but it still may in a box of pulleys in my garage attic.

Dave

[Tom R.]

Re: L-84 Alternator Misalignment

Doug,

I just went through this same misalignment issue with my 63 L-84. Check out this thread I started and solved.

https://www.forums.ncrs.org/showthread.php?t=83297&highlight=alternator+pulley&uid=7508

Long Island Corvette has the correct parts. You'll need the 64 fan (11 blades), the spacer and the SHP pulley. I took mine off with a hex socket from Sears, 3/8" drive with an offset box wrench to get at the nut and lockwasher while holding the hex still. Took a little muscle but got it off. Those parts will solve your problem.

[David L.]

Re: L-84 Alternator Misalignment

This may seem insignificant to some but the distance from the face of the WATER PUMP HUB to the pump housing machined surfaces that mate to the engine varied depending on the year and model on 265,283, and 327 engines from 1955 to 1965 as per the Chevrolet Service News, March 1965.
This distance on 1955-1965 Corvettes and 1955-1961 Chevrolets should be 5 11/16".
This distance on 1962-1965 Chevrolets, 1964-1965 Chevelles, and 1964-1965 Chevy II's should be 5 9/16".
When you install a rebuilt water pump you should check this distance as it is more critical as related to the crankshaft pulley. The cup shaped reinforcements, GM # 3720616, can usually be used to line up the W/P and C/S pulleys, if necessary.