74 BB Alternator Belt Alignment Issue - Need Help

[Victor S.]

I have a factory manual steering 1974 454 that has an alternator belt alignment problem. From the following photos you can clearly see the alternator belt is bowed forward at the alternator. All braces and brackets are original to the engine. Engine was removed from car, components were rebuilt (alternator, water pump, fan clutch, etc). After re-installing the alternator and putting engine back in the vehicle, the belt seems to be out of alignment. The alignment was not an issue prior to the alternator being removed. The alternator cannot be moved backwards to make the alignment straight (see pics below). The problem could be fixed by switching the alternator fan pulley to a power steering pulley which would "straighten" the belt angle - but this would not be correct for the manual steering alternator. All brackets/pulleys are original GM with correct part numbers.

Any thoughts on what may be going on? AND/OR, how I might correct or fix this issue? Am I missing something??
Thanks - any help is greatly appreciated!!
Vic

[Owen L.]

I think you have the wrong alternator pulley. Yours is for an engine with power steering.

[Victor S.]

Thank you so much Owen - I appreciate it. Problem solved

[Tom R.]

Victor...just to add what Owen wrote, and this is from the 73/74 TIMJG, which I suspect you have a copy. Looks like that alternator pulley is for an RPO N41 equipped vehicle.

LS4 Mounting Brackets & Hardware In addition to an adjusting brace, LS4s use one of two lower mounting configurations to secure the alternator to the engine. Non-power steering has a configuration similar to the L48/L82 mounting, while LS4s with power steering share a mounting bracket with the power-steering pump. A third pivot brace extends from the lower support and mounts to the top left waterpump mounting bolt under the adjusting brace for the AIR pump.

[Victor S.]

Thanks Tom - mounting brackets and hardware are factory correct for me - was just having a problem as my pulley looked the same as in judging guide - and I did not realize the pic in the JM was of an LS4 with power steering (as it wasn't stated in the JM that manual steering used a different pulley). As Owen stated I had the wrong pulley for a manual steering car as someone had replaced that pulley before I owned the car. Interestingly, out of 2 AIM's I own - there are no pages for the manual steering LS4/C60 alternator pulley manual steering part numbers that I could find.

Thanks again all for your help folks -
Vic

[Tom R.]

I'll make a note of that...thx Vic
We continue to learn the lesson that, while our best efforts to make these TIMJGs complete, we are limited by lack of access to low-optioned vehicles. We are learning this lesson once again with the 78-79 manual.

Are you AIMs showing the pulley was assembled with the alternator or assembled at the factory? What I'm getting at is a different GM# for the LS4 with C50 and non-N41?

[Victor S.]

Correct Tom - what I can tell you is the 74 AIM does not have a specific part number for the LS4 manual steering alternator pulley. The AIM part number listed for the LS4 in the AIM will not work for non-N41 cars (like mine) as it is an extended pulley which you can see from my posted pics (which was a GM replacement for N-42 cars). So, my pulley shown is for power steering models and as you can see will NOT align correctly. The only thing I can deduct is that the manual alternator pulleys were attached to the alternator as a unit for non-N41 cars. Also, of interest - the 74/350 also had the non extended deep groove pulley(which looks like the one I needed) however, GM dealer parts book list the 350 as a different part number than the LS4 non N-41. Not sure if they would interchange - but they do look very similar.

I always thought the one I had was correct based on what I was seeing in the judging guide for the LS4 (since the pic or text description didn't differentiate for Non N-41 models). Live and learn.

Thanks for everyone's help on this - just want to make everything factory correct. Couldn't get there without the great folks on this forum.

[Tom R.]

The only thing I can deduct is that the manual alternator pulleys were attached to the alternator as a unit for non-N41 cars. Also, of interest - the 74/350 also had the non extended deep groove pulley (which looks like the one I needed) however, GM dealer parts book list the 350 as a different part number than the LS4 non N-41. Not sure if they would interchange - but they do look very similar.

Quite interesting. What's the part number on your alternator, and do you know if its original to the car? I assume it aligns with our table in the TIMJG. I'm wondering if the non-41 LS5 with C60 is a different part number... or, as you imply, could be a small-block A/C type unit.

Do keep us posted and we'll make a note for the next revision.

[Tom R.]

Vic
Well I'm still poking around your LS4 with C60 and base steering. So, curiosity took me to my inventory of buildsheets, which revealed some interesting findings.

Buildsheet box 31 has a caption that reads Alter & Pulley. This was used to call out the alternator broadcast code, or as you know RH for C60 cars. However, there is also a broadcast code for the pulley. I bullet the findings, then explain.
LS4 with C60 and N41 - RH AX
LS4 with C60 and Base steering - RH AL
L48/L82 with C60 and N41 - RH ***
L48 with C60 and N41 - RH 356

My point is that when an LS4 with C60 and base steering came thru...the buildsheet called out a different pulley, code AL! In later C3 years, a process code was used to instruct the worker what to do...documentation type stuff. An example is the 78 Pace Car wheels with the red stripe...well, buildsheets call out the YJ8 wheels, but then a process code instructed them to replace with YJ8s with the red pinstripe. Same in 1974, except the process codes were not used/or listed on the buildsheet. So we have to make some assumptions.

It's also interesting to note the L48 with C60 with RH 356. It was the practice, when a code was not assigned, to use the last three digits of the part number. Thus, 356 is the last three digits of the smallblock pulley, which must have differed from that that came with a base RH alternator. My point is to suggest that the LS4 pulley was changed out at the factory from the RH pulley, and it is either the AL or the 356 pulley!

Interestingly enough, this is the power of buildsheets, especially in the later years of C3 production, to reveal production methods that deviated from normal expectations. I'm not sure the NCRS community has yet to recognize what these build records contribute to our understanding of build options. And why, in our late-model TIMJGs, we reference box #'s to encourage curious owners to study those build records.