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Discussion Starter #1
I have been very fortunate and never had to replace an alternator on my 7.3 PSD’s.

I always keep an eye on my ScanGauge-II and the Voltage tops out at 14.2.

The last few mornings it has climbed to 14.3 and now 14.4 with a brief peak of 14.5 a few minutes after the GPs stop cycling. I want to start preparing for a replacement.

Are any of you just replacing the integrated Voltage Regulator or the entire Alternator?

Where and what model are you replacing with? Thanks
 

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I'd go for the whole alternator, and possibly getting a Large Case 6G Ford alternator (available as a replacement for 6.0L's). It will fit on your truck after you relieve the valley of the alternator mount a bit. Good upgrade without other mods - rated at 140A as opposed to 110A for the stock 7.3L alternator.

I tried rebuilding one myself, but had to take it to a rebuilder for fix for me, as it didn't work afterward. :( So I'd not mess with replacing just the Voltage Regulator, as there may be other things going bad as well.
 

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Discussion Starter #3 (Edited)
Thanks!

So that will be a new Motorcraft brand?

EDIT:
I found your old post.
Thanks
 

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Discussion Starter #4
What FTG-05 said.

I put a large case 6G on my 7.3L to replace the small case 6G and the pulley was in exactly the same spot, so the belt fit exactly like it did with the small case alt. I did use the pulley that came on the small case alt however. The only thing needed was to grind a bit off the mounting bracket where the alternator mounts so the bolt pads fit flush. When the large case alt was set in place, it rocked at the center, so just had to relieve the mounting bracket in the "valley" to make room for the bigger case.

My understanding was that the 6G large case alternator came on some 6.0L's, so that the bracket shouldn't even need to be modified. Here's a thread discussing the mod for the 7.3L. Inexpensive upgrade to 140 amp large case alternator
 
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I've said it before but its worth repeating. I buy my starters and alternators from a shop where they have a workbench in the back with little old men sitting on high stools rebuilding starters and alternators. I would find one of them, talk to the owner and then follow his advice. With alternators bigger is always better so I echo the advice you already received. Alternators never put out what they are rated at for any sustained period of time. Heat is your big enemy and the smaller the frame the more they heat up so going to a larger frame is always a good idea.
 

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I have been very fortunate and never had to replace an alternator on my 7.3 PSD’s.

I always keep an eye on my ScanGauge-II and the Voltage tops out at 14.2.

The last few mornings it has climbed to 14.3 and now 14.4 with a brief peak of 14.5 a few minutes after the GPs stop cycling. I want to start preparing for a replacement.

Are any of you just replacing the integrated Voltage Regulator or the entire Alternator?

Where and what model are you replacing with? Thanks

I recently replaced the original 02 110 Amp small case 6G that came with my truck new. No electrical symptoms bearing noise. I investigated some of the premium upgrade rebuilds and agree that many would be better than new and their price shows it. Their short warranties dont really fit in with their great better than new testimonials. So, I bought a new LARGE case 135 AMP 6G for a 6.0 PSD from O'Reilly for 284, 5 buck core charge, lifetime warranty and it fit my 7.3 without any bracket mods and hooked up in 15 minutes. Lifetime warranty, national chain, I travel thats important, not a skimpy rebuilder 1 year warranty. I bought a rebuild kit and rebuilt my original 110 AMP alternator myself. New rectifier bridge, rotor slip ring, bearings and voltage regulator. Had it load tested and it is good, so I have a spare. Rebuild difficulty, 2 on a scale of 10. Not nearly as difficult as many common PSD maintenance items. Only special tool one will need is a 200 Watt soldering gun, I gad a 300 so all good. There are only eight small solder on crimp connections to do, 10 minutes and easy to position.

The new O'Reilly Alternator works great, I have aprox 5K miles on it. If your alternator has 100k miles on it there is likely more happening than just voltage regulator, slip ring wear is likely. For less than 60 bucks one can just do a complete rebuild. Had I not needed an alternator right away for a job trip to Minnesota I could gave just rebuilt the original, I didnt have time to wait, had to go make a few bucks.
 

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20 years and 150k miles on my original, knock on wood,,,lol
But I don't monitor it either, so this is a good place marker just in case.
Thanks
 

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20 years and 150k miles on my original, knock on wood,,,lol
But I don't monitor it either, so this is a good place marker just in case.
Thanks
Regardless of loading, the slip ring wear, voltage regulator brushes to slip ring surface is just an unavoidable friction wear point. Its not a point thats directly visually inspectable unless one pulls the VR out and partial case disassembly is required for that. I pushed mine way to far, it was almost worn through the slip ring copper and I didnt have any electrical indication. If the bearings had not started making noise I would not have found it, it would have found me. Knowing what I have recently learned and know now, I wont push an alternator past 100k again without a rebuild and or tear down inspection. Makes a case for a spare to rotate in.
 
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