Installing A Large Case Alternator On A 7.3

[DcMoore]

After numerous alternators I finally looked into the main issue a little more. After some searching I found that the small cased 6g alternators that are in the 7.3 Super Dutys go out because they do not cool themselves properly.

Also, the 7.3's factory alternator's output is 110amps and the 6.0s large case alternator puts out 140amps.

I went to O'Reillys and bought an alternator for a 05 6.0. I found some people online that sell a "kit" to install them on a 7.3 but it is just three washers. I ended grinding the alternator bracket so it would fit. If you don't grind the bracket down the rotor will rub on the stator and you'll be back at square one with a bad alternator.


Alternator comparison

You have to grind the front and back.

Ground bracket with the alternator in place.

Finished product

I read somewhere that you need to clock the new alternator but I think it looks way better without the wires going into the top of the alternator. I also read that you have to change the pulleys on the new alternator but mine was an exact match to the new one.

 

[dentexpowerstroke]

3 thick washers also works out to space it.

 

[DcMoore]

Yea, I didn't want to use washers.

 

[TyCorr]

Whats the big deal? My truck still has the stock upper alternator. Im on my 3rd lower. The last one broke. It didnt wear out.

My 03 had the stock one in it when I sold it in 07 at 125k miles and to my knowledge the owner hasnt replaced anything on it since I sold it to him.

Im glad you got it squared away but what would have been so bad about cutting some bushings out of round stock and drilling them for the bolts to pass through?

 

[DcMoore]

Because I didn't want to raise it from it's original location...

The big deal is that I'm tired of those small alternators going out on me.

 

[mustube]

I know of 5 7.3 trucks with total mileage well over 1 million miles and all have OEM alternators

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[DcMoore]

Well that's nice.

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[Gearhead]

What kind of amperage will it make at idle?

 

[DcMoore]

I haven't check at idle.

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[300000 and counting]

I've been through 3 alternators in the last 60,000 miles, this seem like a pretty good idea to me

 

[TRUBBS]

geez why cant anyone applaud what someone does around here anymore?
i like it, small simple upgrade that seams like it will be well worth doing, and im sure it only took about 5-10 minutes with a die grinder to make it fit in the bracket rather then just slap a washer or two on it

 

[TyCorr]

I've been through 3 alternators in the last 60,000 miles, this seem like a pretty good idea to me

Quit buying junk alternators. Parts store alternators put out crap amperage at the cost of keeping it alive.

Idk, ive only had two of these trucks and alternators havent been an issue.

 

[TARM]

What kind of amperage will it make at idle?

I am interested in this as well. As I have no 6.0 experience I guess it could be different that its at idle as RPM of the Alt shaft could be different given pulley size ratios of the belt system difference between the two setups. But I simply do not know.

 

[96stacked&smoken]

I have always heard the 6.0's had a crappy alternator but maybe not?

 

[TyCorr]

@96- I have 275k on my 00 and my 03 is at 225k(with a different owner) and they both still have a stocker in the high position. My 00 has a new alternator down low because the previous one broke. I either got a bad one or there was an alignment issue that wore the bearing funny and it wound up breaking the shaft with only 60k on it. The stocker in the low position never failed, it was removed and tested low. So I replaced it and that parts store pos broke. Ive got a rebuilt from the local guy and hes going to rebuild my stocker. Id like to eliminate the lower and run a high output one from matt or dc electronics.

 

[96stacked&smoken]

Yeah i never hear of the 7.3's failing, just the 6.0's. Not sure what the differences are.

 

[JSchuricht]

I put a large case 200a alternator in my 00 many years ago. Just checked the output at idle this weekend, AC on full, high & low beams, driving & fog lights and say almost 90a @13.9v. Leaning towards a DC power engineering alternator for the 95 tho, waiting to see if they have a sale in a month like past years. Tired of watching my volt gauge dance with the turn signal on.

 

[indyF-350psd]

i too have had a run of bad alternators and found the material about the smaller cases.....ordered my 160A large case alt from quick start....no problems since.....i dont buy anything electrical from the local parts stores always oem or highly reviewed aftermarket.....i always get my batteries tested when the alt goes out as well just to rule out those destroying the alt.....i used the washers to space mine up....

 

[TyCorr]

geez why cant anyone applaud what someone does around here anymore?
i like it, small simple upgrade that seams like it will be well worth doing, and im sure it only took about 5-10 minutes with a die grinder to make it fit in the bracket rather then just slap a washer or two on it

Im not doing that exactly. I wanted it known that stock alternators can and do last. I also wanted it to be available for someone reading the thread that if you source your alternators from the oem or have access to a good rebuilder they arent an issue. I even provided two instances where ive had personal experience.

 

[sootie]

I have always heard the 6.0's had a crappy alternator but maybe not?

its not the alternator itself rather the workload it has. ficms arent easy to power.