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Alternator replace, advice please

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BuggTruck

Alternator replace, advice please

Okay so ive been away a while but BuggTruck's alternator has been on the fritz and finally went out in the freeway with a puff of smoke. Literally. Luckily i got off the road and got the battery unhooked before flames.
Now easy would be to get a 70 amp reman from oreily. But i wouldn't mind upgrading to a 3g. I see the alternator page has much more info on it than before and yet i still am lost. Theres almost no info regarding the 90amp (which should fit with no grinding, and no change to belt layout).

Now i wouldnt mind considering an upgrade to the 130 amp, but with a CA smog pump, i have no idea what i would do to the belts. 🤷‍♂️
I have one empty groove but that is for the compressor as soon as i fix the seized clutch pulley.

While we're all here, any tips to make getting the alternator out easier?

1986 f150 2wd standard cab w/ac 302 5l v8 efi 175,000 miles.

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

This post was updated on .

You have V-belts so there's no need to grind anything, that's for serpentine brackets.
You will still need to flatten the adjuster arm because the 3G mount ears are thicker.
You will also need the 8.25" mounting ears because the 7" will not allow the alternator to adjust.

My truck had dual smog pumps and no belt layout change was needed.
The stock belt fits fine, that's what I used until I went to an L&L swap bracket.

Back off the AIR pump adjuster and get that belt out of the way first.
If the pivot bolt is seized in the alternator there is no easy way to remove the alternator.

Either cut the casting along the length of the bolt in two places and remove the alternator sideways, or drill a hole in the high side and drop some hydrochloric acid in there to eat away the corrosion.
(be careful of eyes and lungs if you go this route)

If you really want a 90A 3G alternator you will have to find one in a '93-'95 pickup....

F1PU-10346-DA
F3HT-10300-GB

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

An additional note to Gary about the alternator interchange...

The Lester #'s for 130A 8.25" alternator are: 7771 for non-threaded and 7765 for the 8x1.25.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Alternator replace, advice please

Administrator

In reply to this post by ArdWrknTrk

Jim - I have some questions that I'm hoping will help me get my head around this so I can upgrade the write-up"

ArdWrknTrk wrote

You will also need the 8.25" mounting ears because the 7" will not allow the alternator to adjust.

Can you say more about that? Why won't the alternator adjust with the 7" ear-to-ear spacing?

ArdWrknTrk wrote

If you really want a 90A 3G alternator you will have to find one in a '93-'95 pickup....

F1PU-10346-DA
F3HT-10300-GB

You mentioned the 7" e2e spacing in the first quote but said "90A" in the second quote. However both were talking about the small case alternator, which has 7" e2e spacing and originally was rated at 90 amps. Right? I just want to make sure I am following. Perhaps we should refer to these as the small-case and large-case alternators in the write-up as people are selling the small case with other output ratings than 90A?

And, then you gave the part numbers for a small-case alternator that was used in certain '93 - '95 F-Series pickups. Do you happen to know more specifics about the pickups, like the engine and Lester # for those part #'s? Just thinking about updating that spreadsheet.

ArdWrknTrk wrote

An additional note to Gary about the alternator interchange...

The Lester #'s for 130A 8.25" alternator are: 7771 for non-threaded and 7765 for the 8x1.25.

Do you know the applications for the 7765? I've googled it and find bits and pieces of info, but it would sure be nice to find a good table that shows applications by Lester #. Then we could just refer people to that or copy that and put it on the page instead of having our own.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

This post was updated on .

Gary,

The slightly smaller body of the 90A (four hole) 7"mount will allow the pivot bolt to be inserted and a small amount of swing.

We have to make a distinction between BODY size (135mm v/s 148 mm) which is about 1/4" radially, and MOUNTING distance (7" v/s 8.25")
8.25" seems to work with all V-belt setups.

The 90A alternators found in some pickups are 8.25" for 300-6.
Serpentine Windsor's had the 7".

I don't know of any table listing application by Lester number.
I usually look for the alternator application and then check for the number.

IIRC Bill's son Matt worked in the aftermarket industry. Perhaps he has a resource for you.

HTH

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Alternator replace, advice please

Administrator

Ahhhh! So there are 3 variables: body size of 135mm v/s 148 mm; ear-to-ear mounting distance of 7" or 8 1/4", which doesn't always equate to body size; and amperage, which initially started as 90A and 130A for the smaller vs larger body size. Right?

If that's right then it helps significantly. I've been struggling to understand everything we have and everything I've read, and was trying to fit it all into two variables: body size/e2e mounting distance and amperage.

As for Matt, I think he's changed jobs. But perhaps he still has access to a chart/listing? Bill?

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Alternator replace, advice please

Administrator

I don't know if he does any more, he is IT manager for Olympus Foreign Parts, a division of Guaranteed Parts. I know on the poly groove (not serpentine) 460s, a Taurus 3.8L alternator is a drop in and when Matt's 86 alternator went FUBAR I seen to recall that the one from the parts truck, a 1990 F250 with 460 fit just fine.

On some applications the body halves may need "clocking" to get the hot stud where it won't touch anything. Wiring will need to be examined whatever you do, the crackhead system on the 2G alternator models defies belief as everything except the starter goes through the alternator harness. The fusible links are what usually fail and let the smoke out.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

This post was updated on .

In reply to this post by Gary Lewis

Body size and mounting style are unrelated, but body size and amperage are one in the same.
In a stock configuration 90A are always four hole 135mm diameter and 130A are always two hole 148mm.

8.25" are for swing mount V-belt application (and 300-6 solid mount)
7" will fit the serpentine Windsor's cast aluminum bracket.
No clearance needed for the 135mm case, but needed for the 148mm large case (two hole, 130A)

Not to confuse the issue. There are more 3G mounting options, but they do not fit bullnose.
Side bolt mounts, there is a Vee pattern mount that fits modular motors, etc....

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

This post was updated on .

In reply to this post by Gary Lewis

Gary,
I failed to note among the small case 3G's the '92-'94 Aerostar 3.0 uses Lester 7749-3 and the 460 uses Lester 7749. (without the suffix)

EDIT***
These two numbers and their applications are the 90A ones Buggtruck says he is looking for

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Alternator replace, advice please

Administrator

Jim - I'm "with grandtwins" and it makes concentrating difficult. This whole thing appears to need concentration as it isn't clicking with me. So, when I can devote some time I'll try to get my head around it.

Having said that, if you have suggested any verbiage, or upgrades thereof, for the swap page please send it on.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

Im sure you're very busy and don't mean to distract you from the more important task.

I was just replying to your questions in the most through and succinct way I can.
On my phone I lose the replied to text, so sometimes I fail to fully address your questions in one reply.

Maybe we should stop cluttering this thread and revive the 3G swap one?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

BuggTruck

Re: Alternator replace, advice please

In reply to this post by BuggTruck

Okay awesome! Have more info to go on now, thank you! Working on getting the alternator out right now before the sun gets too high.

Still confused on the belts though. The write up says that 1 vbelt can only handle up to 100amps and after that theres slippage, noise, and possibly early wear of components. A 2 belt system would be needed. This was the source of my confusion, and one contributing factor for choosing a 90 amp over a 130. I am no expert, on a budget, and this is my main mode of transport currently (so on a time budget); so changing a belt configuration seems outside of the scope of what i can do. For that matter i might just put the 70 from oreily in and upgrade a little down the road.

1986 f150 2wd standard cab w/ac 302 5l v8 efi 175,000 miles.

BuggTruck

Re: Alternator replace, advice please

In reply to this post by ArdWrknTrk

Thanks for the aerostar suggestion. My parents had a 93 aerostar fir a very long time, that thing was a champ!
However maybe I'm remembering wrong but i thought the 93 aerostar we had had a odd sideways mounting holes on the alternator? Been a while since i helped my dad change that, but i remember there was something odd...

1986 f150 2wd standard cab w/ac 302 5l v8 efi 175,000 miles.

Dorsai

Re: Alternator replace, advice please

In reply to this post by BuggTruck

BuggTruck wrote

Still confused on the belts though. The write up says that 1 vbelt can only handle up to 100amps and after that theres slippage, noise, and possibly early wear of components. A 2 belt system would be needed. This was the source of my confusion, and one contributing factor for choosing a 90 amp over a 130. I am no expert, on a budget, and this is my main mode of transport currently (so on a time budget); so changing a belt configuration seems outside of the scope of what i can do. For that matter i might just put the 70 from oreily in and upgrade a little down the road.

Crazy question, but do you actually need more amperage? It's one thing if you do, but if you don't, why bother?

Matthew
1980 F-150 Custom 2wd longbed, 300-6, C6, 2.75 rear axle
Atlanta GA

BuggTruck

Re: Alternator replace, advice please

Right this moment, im am probably just okay, but with the radio and planned additions on my project truck i kinda want spare amps. I could just as easily upgrade the alternator later i suppose...
Wanted more lighting inside cab as well as bed and under the hood, possibly a cb radio, chargers for phone.

Wanted to add larger speakers (not insane, but better). Right now i only have 2 5.25" speakers in the door. My radio could support up to 4 speakers and a base. If i added a small amp as well i could up the speaker output. I don't want to go deaf, but my puny 2 speaker setup struggles to be heard.

Part of my future plans are to add some upgrades to camp in the bed with the shell. So i was looking to add a second battery (with an isolator of course!) and an inverter, as well as additional lighting.

1986 f150 2wd standard cab w/ac 302 5l v8 efi 175,000 miles.

85lebaront2

Re: Alternator replace, advice please

Administrator

In reply to this post by BuggTruck

Aerostars were front engine RWD, I believe on a Ranger based chassis, Windstars were sidewinders based on a Taurus derived chassis.

Bill AKA "LOBO" Profile

Gary Lewis

Re: Alternator replace, advice please

Administrator

In reply to this post by ArdWrknTrk

Jim a We probably ought to revive the other thread. Be my guest!

Buggtruck - A v-belt will only support ~90 amps w/o some slippage. But just because you have an alternator rated for more doesn’t mean it will try to generate more. That depends on the state of the battery and the type of regulator.

A well-charged battery would not trigger a high-current output under normal conditions. Even with a big stereo you shouldn’t be pulling that much current unless you run the stereo with the engine off for an extended period.

And there are regulators available with delay built in that would slow the output’s ramp up and therefore the slippage.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

This post was updated on .

In reply to this post by BuggTruck

If your 2G smoked it's more than likely it is the infamous 'fire plug' or as Bill said the fusible link.

Given the mods you want I would just use the easily found 130A 8.25" unit from a '92-'94 Taurus/Sable with the 3.8l engine.

Dorsai wrote

Crazy question, but do you actually need more amperage? It's one thing if you do, but if you don't, why bother?

Yes, a single V-belt will only transfer enough power for about 100A but the advantage of the 130 is that it will put out more at idle than the 2G's 65A maximum output.
The diodes and heat sink are bigger so it runs cooler at the same output as a 90A 3G.

The battery stays charged, the lights don't dim with the blower on, etc...

I have a single V-belt.
I sent Gary my double sheave one.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: Alternator replace, advice please

Administrator

In reply to this post by BuggTruck

Here is a 7749

From this NQS page, which offers a application.

https://store.alternatorparts.com/partno20229142replacesfordf2uu-10300-cdlester77497758.aspx

So, hens teeth can be found

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

FuzzFace2

Re: Alternator replace, advice please

One thing that was partly brought up was the single belt and the belt slipping making noise.
I here most of the time this happens at start up when you just pulled a lot out of the battery and the ALT is trying to charge it back up.

You can install a slow start regulator into the ALT. This will bring the ALT on slowly and keeps the belt from slipping and making noise.
When my 1G ALT goes out and I go with the 3G ALT because I only have a single belt this is the way I am going to go, slow start up.
Dave ----

Dave G.
81 F100 flare side 300 six / AA OD / NP435 / 2.75 gear
http://cars.grantskingdom1.com/index.php/1980-Ford-F100?page=1
81 F100 style side 300 six/SROD parts truck -RIP
http://cars.grantskingdom1.com/index.php/1981-Ford-F100

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