Alternator pulley leaking..

[ShadowsPapa]

Just a quick update as I remove the OEM decoupler...

1) The dust cap was difficult to remove with a pick or small flat head screwdriver (for me at least). I simply drilled a small 1/8" hole in the center of the cap and used a punch to pry it out... worked great
2) I had a lot of grease in the center of my decoupler pulley and it might be the reason the idler pulley looked so wet and crudy? I'm replacing both idler pulleys while I'm in here
3) I personally needed all the leverage possible for the removal of the decoupler pulley... got a long 19mm box end to hold the large hex key in the body of the pulley and put a pipe extension on the 3/8" wrench with the 7/16" socket on the alternator shaft portion (10mm head) of the tool
4) If looking at the pulley on the alternator while it's off the vehicle, turn the 7/16" socket counter-clockwise (follow the direction of the arrow stamped on the alternator) while holding the 19mm box wrench stationary. If you do this while the alternator is still on the vehicle and you're standing at the grill, then you'd turn the 7/16" socket clockwise(or towards the driver side). Again, always turn the 7/16" socket the same direction of the stamped arrow while holding the 19mm box wrench stationary to REMOVE only
5) Reinstall

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GREAT post - should be a sticky somewhere. I bet you'll save someone some work one of these days with that detail and the pictures.

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[darkhorse13]

GREAT post - should be a sticky somewhere. I bet you'll save someone some work one of these days with that detail and the pictures.

Thanks! The JL Forum hyperlink in post #22 in this thread was helpful but it still left me a little unsure as a first-timer to this repair. I wanted to post EVERYTHING I could to make it simple enough for another beginner I'll be honest and admit it took me a minute to figure out the direction of the wrench to "loosen" vs "tighten" as you have to think of the decoupler pulley as the object that threads onto the alternator shaft.

 

[Vtur]

Thanks! The JL Forum hyperlink in post #22 in this thread was helpful but it still left me a little unsure as a first-timer to this repair. I wanted to post EVERYTHING I could to make it simple enough for another beginner I'll be honest and admit it took me a minute to figure out the direction of the wrench to "loosen" vs "tighten" as you have to think of the decoupler pulley as the object that threads onto the alternator shaft.

So lefty loosy right?

Nvm. Re-read your comment and it's a reverse thread.

 

[ShadowsPapa]

So lefty loosy right?

Nvm. Re-read your comment and it's a reverse thread.

They put the danged alternator on these things on backwards!

 

[darkhorse13]

So lefty loosy right?

Nvm. Re-read your comment and it's a reverse thread.

I updated post #30... let me know if that makes more sense? But yes, the decoupler pulley is reverse threaded when looking at it on the bench

 

[bgott]

Well I ordered the Litens decoupler pulley and tool as well as a new serpentine belt. For reference I have a 2020 JTR with 61,000mi currently. I'm chasing a whistling sound and I'm going to systematically try to replace parts to remedy the issue. It might require time and duplication of parts removal but I can perform the maintenance myself. For reference, the whistling noise started around 59,000mi I believe. I noticed it during a trip in Oct 2024 to Moab. I'm not sure if my "racing stripes" are the beginning of the oil leak or the remnants of a completely oil-less decoupler.

My current approach to finding the source of the whistle...
1) Verify power steering fluid level and visual inspection of parts listed below
2) Remove serpentine belt and spin idler pulleys by hand to feel for any grit or slop
3) Replace decoupler pulley and serpentine belt (test drive, then perform next step)
4) Replace idler pulleys (test drive, then...)
5) Replace water pump... there's a great thread on here where the "whizzzzing" sound was a bad bearing in the water pump
6) If all else fails, just keep the radio above volume level 15

Might be an idea to start with an automotive stethoscope. Harbor Freight has them for under $10.

 

[Vtur]

They put the danged alternator on these things on backwards!

Reverse threaded because the coupler goes righty and the shaft lefty.

 

[ShadowsPapa]

Reverse threaded because the coupler goes righty and the shaft lefty.

If they put the alternator on the engine facing the right direction, it wouldn't need to be reverse threaded.
I guess they finally decided that trying to cool an alternator by pulling air in from the back while the cooling fan was trying to shove air the other direction wasn't a great idea.

 

[Vtur]

If they put the alternator on the engine facing the right direction, it wouldn't need to be reverse threaded.
I guess they finally decided that trying to cool an alternator by pulling air in from the back while the cooling fan was trying to shove air the other direction wasn't a great idea.

Jeep is the only vehicle that does it. They wanted up high but has no space so backward it is lol. Make it harder to replace the belt too

 

[Lost1wing]

I saw my entire alternator pulley depart the vehicle and pass me a few years ago. My Jetta has the same setup. I didn't really think that the passing part was from my vehicle. My alternator and air were still working, until I slowed down and the rpms dropped. Then the battery light came on but the air continued to work. I pulled over and popped the hood. I could see the alternator belt still turning so I thought it had just failed. I drove an hour to my brothers house where I was able to see it better. That is when I realized that part I saw on the highway, traveling slightly faster that 75mph was my alternator pulley. The belt was still on the 1/2 inch shaft of the alternator. That is why the air was still working. I got lucky the pulley didn't cause any damage on the way out and the belt hung on the shaft.

I don't know how difficult it is to remove the pulley on our JT, but it is a bear on the Jetta, not located in a convenient location.

 

[g2020]

This pic of an oil leak was taken in the evening on December 30th. Because my selling dealer is a "Warranty Forever" participant (covers power train w/ no deductible), I brought my vehicle to their service department at 7:00 a.m. on New Year's Eve. It was a VERY slow day for them. The only thing that held up the repair was that the warranty folks needed to process my receipts to show that I had complied with the warranty terms.

One of the benefits of doing monthly reservoir-only PSF replacement, using a turkey baster, is that the owner has his/her eyes on the engine at least once per month. I consider myself lucky to have caught this oil leak, within one day after it started, while I was checking the level in the PSF reservoir.

My selling dealer diagnosed this issue as a faulty oil cooler and valve cover assembly. After six days in the shop, including holidays, the repairs were completed on Tuesday, January 6th. No loaner. Learned quickly how to use Uber Eats.

Three days later...the line of oil has reappeared after cleaning it three times. Much less oil each time. I suspect that the original cause was the alternator pulley, but the tech found the bigger issues and stopped there. I've bought the Litens 920080A Decoupler Pulley and Lisle 57650 Alternator Decoupler Removal Kit, and will replace the decoupler pulley next week. Big shout out to @Maximus Gladius for insisting, from the start, that this leak was caused by the clutch pulley wheel.

Although my dealer found bigger issues, I believe the following pic is a good example of a faulty alternator decoupler pulley. If this is correct, the countdown to alternator failure started in late December.

My comments above were revised on January 9th.

 

[ShadowsPapa]

This pic of an oil leak was taken in the evening on December 30th. Because my selling dealer is a "Warranty Forever" participant (covers power train w/ no deductible), I brought my vehicle to their service department at 7:00 a.m. on New Year's Eve. It was a VERY slow day for them. The only thing that held up the repair was that the warranty folks needed to process my receipts to show that I had complied with the warranty terms.

One of the benefits of doing monthly reservoir-only PSF replacement, using a turkey baster, is that the owner has his/her eyes on the engine at least once per month. I consider myself lucky to have caught this oil leak, within one day after it started, while I was verifying the level in the PSF reservoir.

My selling dealer diagnosed this issue as a faulty oil cooler and valve cover assembly. After six days in the shop, including holidays, the repairs were completed on Tuesday, January 6th. No loaner. Learned quickly how to use Uber Eats.

I am watching the metal surfaces beneath the pulley like a hawk because at least one member of this forum would have sworn up-and-down that this was a faulty alternator. I have not heard any unusual noises or had any warning indicators light up. I will have the alternator tested at O'Reilly and possibly at a local independent shop. The alternator received a small amount of the oil spray/mist, but the mist coated things behind and to each side of the alternator pulley MUCH more than in front of the alternator pulley.

If this issue was misdiagnosed and the alternator is still on its way out, I will come back to this thread. The alternator, of course, is not part of the power train, so replacing (any part of) it would be out-of-pocket.

Why would the alternator be on its way out? What does an oil leak have to do with an alternator?
If the clutch is bad, replace it, not the albator. Testing the alternator will only show you so much, especially at an auto parts store

 

[ChrisNLA]

Why would the alternator be on its way out? What does an oil leak have to do with an alternator?
If the clutch is bad, replace it, not the albator. Testing the alternator will only show you so much, especially at an auto parts store

Alternator went out in the ole ladies van. Broke down in the Oreilly's parking lot, and I *thought* we bought the alternator that was in it from Oreillys.

So they tested it and said it was bad, but couldn't find it in their system.

Dawns on me that I bought it from AutoZone.

Went to the first AutoZone, their alternator tester is broken.

Went to the second AutoZone, their alternator machine keeps fritzing out while in use (also broken).

About to lose my mind. I tell the guy the OREILLYS machine worked fine and said it was bad.

Guy goes - OK I trust Oreillys and swaps it out for me. Van works fine now. I still have the OEM one for it as I want to get a good alternator shop to look at it for me. We were having issues but I'd like that original one to be kept for later as the remans from the stores suck.

 

[g2020]

Why would the alternator be on its way out? What does an oil leak have to do with an alternator?
If the clutch is bad, replace it, not the albator. Testing the alternator will only show you so much, especially at an auto parts store

Updated my description from "alternator" to "alternator pulley" to be crystal clear. Didn't know I had to be so specific. I will also update the testing comments in my post to meet the elusive forum specifications.

It would be on it's way out because the line of oil in my picture looks just like the line of oil in the first photo in the (Wrangler) post shared by Gregj in post #22 in this thread. The resemblance is not as clear in any of the previous photos shown in this (Gladiator) thread.

In this thread, the (recommended) decoupler pulley remove & replace process is shown in post #30, and the key posts include #21, #24, #26, #30, and #32.

This post was revised on January 9th.

 

[ShadowsPapa]

Updated my description from "alternator" to "alternator pulley" to be crystal clear. Didn't know I had to be so specific. I will also update the testing comments in my post to meet the elusive forum specifications.

Huge difference and some people here don't even know there is a clutch or "decoupler".
Yes, when talking about issues - best to say what you mean.
You said "alternator on the way out" - that's the generating device - not a decoupler or clutch, two different parts. And you mention having a store test the alternator - another statement supporting the alternator on the way out idea. Parts stores are extremely limited in what they can test - it's a "go/no go" test for the most part, nothing more. Most won't test for weak diodes on the way out, just will a 220 amp alternator reach at least 176 amps and if it will then it's good to them, even with a diode on the way out or output ripple freaking out the computer.

You did say ALTERNATOR on the way out - distinct issue from an oil or lube issue.

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