A discussion about alternators and their "clocking"

[RustyPile]

I posted a reply concerning the "reclocking" of alternators in another thread. But due to inactivity, the thread soon slipped down a page or 2 and has gone unnoticed.. I considered posting this new thread in the "ELECTRICAL" forum, but this forum seems to get more views. At the moderators discretion, this thread can be moved or even deleted..

Lately, no, actually almost continually, there has been several discussions concerning installing higher output and/or internally regulated alternators and I've been following all those threads/posts.. "Which one do I need?"... "Which amperage output do I look for?". "Which make/model vehicle should I consider when choosing an alternator?".... I see a lot of emphasis placed on the "clocking" of an alternator.. The "clocking" of an SI type and a few other alternators is a totally unnecessary consideration when making your selection as the "clocking" can be easily changed.. When these alternators are assembled, all the internal components -- stator, rotor, diode bridges, voltage regulator, etc. -- are assembled into the rear case half.. The brushes are placed in the brush holder in the fully retracted position and held by a plastic rod. This rod passes over the end of the brushes and sticks out through a conveniently placed hole in the back of the case. The rotor shaft is inserted into the rear bearing.. The two case halves are slid together in what ever "clock" position the particular application calls for.. The four bolts are installed and the plastic rod is removed, allowing the brushes to make contact with the brush rings..

Buy/select an alternator of whatever amperage you desire and/or need.. Remove those 4 bolts holding the case halves together.. Gently and slightly separate the case halves about 1/8" - 3/16" leaving the stator fully seated in the rear half and the rotor (the part/shaft that has the pully on it's end) lifted slightly but still partially seated in the rear case half.. Rotate the front case half to the proper "clock position" for your application.. Reseat the case halves and replace the bolts.. If you slip up and separate the case halves too far and the brushes slip off the brush rings, just fully separate the case halves, reinsert the brushes into the brush holder.. The brushes can be held in place using the red plastic tube that comes with a chemical spray cleaner.. Position the case halves in the needed "clock position" and push the case halves back together.. Install the four bolts, remove the plastic tube, and you're good to go..

[dmjlambert]

In my opinion you don't need to worry about clocking at all. On the original alternator the truck came with, there is a large recess in the case. When clocked a certain way, the alternator fits over the valve cover and lets you get a lot more adjustment range in that groove in the upper bracket.

As soon as you replace the alternator with a newer model that does not have that large recess, you lose that large adjustment range. So clock the new alternator any way you like, for cosmetics only. You could clock it such that your wiring is further away from the engine to give the wiring a little less heat. The clocking on the original alternator places the wiring as close as possible to the engine, and the alternator itself will get quite hot, so clocking for that reason is probably insignificant.

So, don't worry about how it's clocked. Or, go ahead and clock it as you like and then when you pop open the hood you can point to it and tell your friends you clocked it and describe the procedure. Tell them it's now ready for 220, 221, whatever it takes.

[firedemon]

i wondered why i couldnt get any adjustment from my alt. i never saw the factory alt and the large recess . i also have tall valve covers and thought it was just the tall covers . i can barely fit a piece of paper between the alt and the covers . i found a belt that fits real tight and use the engine to put it on while the adjustment bolt stays tight . i dont suppose you can use the recessed case half on the newer alt ? probably why they went with the long pump and moved the alt to the passenger side

[Rich72C10]

well I been wondering about all the clocking and what, if any problems would occur if the Alt had the wrong clocking (other than being late for work?). Thank you for posting this!

Personally I don't want to be opening a new Alt up. Lord knows I'll sneeze when taking it apart and all the bits will fly out! In the words of D-O... No thank you...

Is there one common different clocked Alt letter to stick with than another?

[MikeB]

Thought this might come in handy. There's a clocking chart about 80% of the way down the page.

http://www.madelectrical.com/electri...elcoremy.shtml