Eaton swap alternator, smooth idler pulley and bolt fitment help

T

tdotcv

Junior Member
My car has the eaton swap, I was cursing when I heard a grinding noise coming for underneath the hood. I quickly pulled over and opened the hood, the alternator fell off the custom brackets and the alternator pulley was grinding against the timing cover, then the belt snapped, rubber everywhere. Alternator broke and so did the alternator pulley and nut. I believe I didn't install the alternator correctly. Please advise me how to do it!

I know the smooth idler pulley is installed backwards on the alternator bracket but which way is backwards, pic 3 or 4, I don't know. I also don't know which way the bolt that holds that pulley is supposed to go, pic 1 or 2, and I need to know the length of the bolt, and washer and what nut are used. I need to do it right this time.

I added four pics with numbers so someone here can show me which two pics are correct, pics 1 or 2 and 3 or 4. Thanks in advanced.
 
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I'm not an Eaton-swap expert, but it looks like either 1 or 2 would work, as long as the bolt doesn't hit or rub on anything.

As for 3 & 4, since it's a smooth pulley, as long as the belt rides on it correctly it shouldn't matter which way you mount it.
 
You can use a short bolt to keep the pulley on, and use a stud for the left side of the alternator.
Or a long bolt all the way through that doubles as a stud.

The pulley goes on as seen in picture 3. However, there are so many variations of brackets out there, you do what makes the most sense.
It looks like you have Terry's Brackets. That bracket takes the F-150 alternator pulley. GP-712 I believe.
 
My pulley only works best set as in pic 4, not 3. 3 it rubs the timing cover. As you said, there's little variations.
 
my pulley is as in 4 also but i did need to file the edge of the pulley as it rubbed in a few spots (replacement pulley)
 
Update

Thanks guys for the reply's. I picked up a rebuilt alternator with a 6 rib pulley already installed at a local alternator shop. $120 but I had to give him mine or else $150. The pulley looks like the right one, looks exactly like the GP-712.

I ended up using a full thread bolt through the smooth idler and added a washer to hold down the idler and on the other side I used a thin stud because there wasn't much thread left on the bolt and a washer too. I think that will hold down the alternator but now another question has come up.

I noticed that the idler and alternator pulley don't line up, I added a pic, are they supposed to line up or not? I hope I have the right alternator and pulley, it looked just like the Marauder one.
 
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Your right about flipping. Its about 0.9 cm away from the bracket when I flipped it its only about 0.5 cm away. If I can find some thin washers it should come about 0.1 cm even closer.
 
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Don't shim the idler pulley.

You may need to switch the alternator pulley.

With all these brackets floating around from different people, its a guessing game.
 
If it is the stock Marauder Alt pulley, get the F150 pulley. It will move the pulley out enough (toward the front cover) to line up perfectly.
 
sparky1562 said:
If it is the stock Marauder Alt pulley, get the F150 pulley. It will move the pulley out enough (toward the front cover) to line up perfectly.
Click to expand...


Have you looked at the pictures? Besides, a stock pulley wouldn't fit or function.


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justbob said:
Have you looked at the pictures? Besides, a stock pulley wouldn't fit or function.
Click to expand...

Yes, I did. The F150 alternator pulley stands a little proud of the alternator versus the stock Marauder. If he has the stock Marauder (or Mark VIII pulley for that matter as they are the same), changing to the F150 pulley, as two others have noted, will help correct the mis-alignment, along with flipping the smooth idler pulley around.
 
I have no idea what pulley is on the alternator but I know its not a stock Marauder one. It looks identical to the motorcraft one everyone uses. The pulley has F5OU F2A stamped on it. The motorcraft has F5AU A2A. Does any one know what is stamped on the f150 pulley.

The alternator pulley sits right against the alternator maybe 1mm out. Are you saying the f150 pulley sticks out a few more millimeters away and lines up with the idler pulley? Do you have a pic for reference. That sounds like it will solve this problem once and for all.
 
sparky1562 said:
Yes, I did. The F150 alternator pulley stands a little proud of the alternator versus the stock Marauder. If he has the stock Marauder (or Mark VIII pulley for that matter as they are the same), changing to the F150 pulley, as two others have noted, will help correct the mis-alignment, along with flipping the smooth idler pulley around.
Click to expand...

Hey Sparky!
 
sparky1562 said:
Yes, I did. The F150 alternator pulley stands a little proud of the alternator versus the stock Marauder. If he has the stock Marauder (or Mark VIII pulley for that matter as they are the same), changing to the F150 pulley, as two others have noted, will help correct the mis-alignment, along with flipping the smooth idler pulley around.
Click to expand...


What I'm trying to say is that the OE Marauder pulley would hit the timing cover before you even mounted the alt. and the clutch wouldn't work out so well turning backwards.


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"
 
justbob said:
What I'm trying to say is that the OE Marauder pulley would hit the timing cover before you even mounted the alt. and the clutch wouldn't work out so well turning backwards.


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"
Click to expand...

Gotcha! Forgot you guys have the clutch.
 
tdotcv said:
The alternator pulley sits right against the alternator maybe 1mm out. Are you saying the f150 pulley sticks out a few more millimeters away and lines up with the idler pulley? Do you have a pic for reference. That sounds like it will solve this problem once and for all.
Click to expand...

My car is at the body shop, so I cant get a picture. Yes, the F150 pulley sits a little farther out, maybe 3-4 mm IIRC. With stock 4.6 Alternator pulley (with out the clutch!) the pulley is about 5 mm from the cover when installed. The F150 moves it to about 1.5 to 2 mm from the cover (1/16"" inch).

I used Jerry's brackets and the F150 alternator fixed my alignment and I believe that is what both he and Terry based their brackets on.

I believe that the A2A marking is the "F150" pulley. It is used a bunch of Fords, not just the F150.
 
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I believe quite a few people are running into the same problem when they buy rebuilt alternators. They use the alternator pulley that comes attached to it because it has 6 ribs. I think the alternator I had was from a cobra because I searched the part numbers on the pulley. I went to an alternator shop and asked for a pulley with A2A stamped. After they switched it, the pulley didn't sit flush against the alternator anymore and maybe 4mm out much better for aligning the belts.

I also came across another problem that I want to mention because it might someone doing the swap. The top smooth idler pulley off the passenger side of the timing cover part number XR3Z-8678-BA that is installed backwards on the alternator bracket was sitting against the timing cover when I installed the alternator with the bracket. I didn't want to use washers on the alternator bracket because then it would bring the belt out even further on the driver's side. I just replaced it and it fixed the problem. The bearings on the smooth idler pulley were shoved in because of all the years being used. That's why belts and pulleys weren't aligned. While you are changing the belt or the alternator check the smooth idler pulley to see if it is wrapped and need to be replaced, check all of them actually.

But now another problem, how the heck do you install the 980 belt, it's extremely tight. Where is the best part to route the belt at the end, over which pulley? I have been trying for a whole day now.
 
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