Another Alternator Pulley Post...

[Stealth TDI]

Hi,

I've been getting some squeaking from the alternator area. I was afraid it was a bad bearing. The problem went away over the winter. Now that it's warm, the problem is back and even worse. Sounding more like a belt, I gave a look and found chunks missing out of the serpentine belt. So I figured that was the problem... a squeaky belt. I replaced the belt and the problem persists.

Upon inspection of the alternator pulley, I discovered the pulley is rotating along the shaft. I'm unsure if it can be tightened. After reading in here, it looks like it must be replaced. BTW, removing an alternator from an A3 TDI is an absolute PITA. I had to remove the right-hand headlight, uncouple an AC bracket, then lift the AC line up about 18" to clear a path for the alternator to come out from behind where the headlight used to be. :shock:

ANYWAY, my goal is to figure out how to tighten up this pulley or replace it. I'm certain there is nothing wrong with the alternator. I found a cover that I've removed. However, there are tools needed that I do not have. Check this out:

This photo is looking at the alternator from the pulley side. These splined fittings are inside the pulley area. Surely someone in here has replaced an alternator. Looking at NEW alternators, it appears they are not shipped with pulleys. So this pulley would have to come off whether I'm replacing the pulley or needing to transfer it to a new alternator. That also suggests the pulley can be replaced independently. Does anyone know what I need to do to replace this pulley?

With over 200,000-miles on the car, the alternator owes me nothing. Should I just replace it while it's out? My gut says NO. But it would suck to put it back in and have it fail in a few months. :lol:

I appreciate your advice...

Thanks!
Scott

 

[Stealth TDI]

Oh,

I recall reading about how MetalNerd has the appropriate tool to remove the pulley. I've found it:

But which piece turns which way? And when it comes off, is one of the splined pieces attached to the pulley? Or does it come off separately? I'm heading to NAPA in the morning to see what they have to say. But I'd rather hear from folks who've actually done some work on this particular alternator. Also, I recall reading up on someone replacing their brushes and/or voltage regulator. Should I do it? Or should I just wait until I have problems? I'm so seasoned on getting the alternator out now I could probably do it with no problems next time.

Take Care,

Scott

 

[DPM]

In the absence of any other data I'd say you'd unscrew the pulley in the opposite direction to normal rotation; screwthreads are normally implemented so that normal useage will tend to tighten the fastener.

So if the alt rotates clockwise, you'd want to hold the shaft (small spline) still, and turn the pulley anticlockwise...

 

[Stealth TDI]

Okay.

Here are the photos:

First, my alternator removal lesson... The AC line is smack in the way of getting the alternator out nice and easy. The only way to move the AC line is to unbolt it and lift it up to slide the alternator under it. The only way to unbolt and lift the AC line is to remove the headlamp. The only way to remove the headlamp is to remove the grill... :roll:

Here you can see the AC bracket I needed to unbolt after removing the grill and headlamp...

Now another lesson... I didn't need to remove the alternator to replace this pulley. In fact, the pulley was on there so tight I HAD to reinstall the alternator so it would be braced well enough for me to hork on the 30-spline pulley nut with a 20" cheater bar. That thing was TIGHT!
Here's the old pulley. You can see the center section just sort of let go and the outer section started to slip around the center piece...

It's tough to see; but there are little tiny cracks along the inside of the out piece. You can also see a chip on one part...

The nice, shiny new pulley...

Oh, here's the alternator shaft (I know... I said "shaft"...) :lol:

Apparently, these wacky pulleys made their first appearance in TDIs. They're designed to engage the alternator in only ONE DIRECTION. I guess when you cut off the engine either the sudden stop of the engine or a TINY amount of reverse motion (as the engine comes to rest) causes small voltage spikes that can shorten the life of the alternator. This pulley allows the alternator to spin down separately from the engine. I guess it was an "upgrade" to prolong the life of the alternator. One parts guy told me all the new VWs have these things. But my 2003 Passat w/1.8T does NOT have this pulley. So I'm guessing it's a TDI-only thing. What I don't understand is why a TDI would need this pulley and the other plants do not. :shock:

Oh well. It was an interesting lesson. I now have the tool in case I need to swap pulleys again. Now I'll monitor an intermittent N109 Fuel Cutoff Valve fault that MAY have been caused by the pulley. I have a spare part on hand. But the new pulley might have fixed my problem. Time will tell. My VAG-COM has paid for itself over and over again. 8)

Take Care,

Scott

 

[DPM]

Used by other brands too. What you have to remember is that because a diesel only revs to 5k max compared to 7-8k in a modern gasser, the drive ratio is radically different. Your alt is spinning at perhaps 12-14k at the redline. That's a lot of inertia, and it'll drive the engine if it so desires; the pulley isolates it...

 

[Beowulf]

Okay.

The nice, shiny new pulley...

Do you have a part number for the new pulley? Did you get it from the dealer, NAPA, or somewhere else? Thanks.

 

[Stealth TDI]

Sorry,

This post escaped me. Free wheel pulley part number is 028 903 119 AA. The ribbed belt pulley Retail price is $114.20. I got mine at Impex for about $96.

Scott

 

[Beowulf]

Sorry,

This post escaped me. Free wheel pulley part number is 028 903 119 AA. The ribbed belt pulley Retail price is $114.20. I got mine at Impex for about $96.

Scott

Thanks for the info, Scott. I don't need a new one now, but it's always good to be prepared.

 

[bigtom111]

I would have had to really fight the urge to coat the inner hub of the old pully with loctite and slap it all back together.

 

[ninedee_golf_tdi]

Another possible source for the dreaded cold weather, first start in the morning, ear splitting squeal ?

 

[Stealth TDI]

Loctite would not have worked. There's nothing in there for it to work on. The surfaces are smooth in the broken part. Luckily, my new part arrived before my drive to BugOut 59 where I took 2nd place in my show class. Had the part NOT showed up, I would have JBWelded it and hoped for the best until the part arrived. However, JBWeld would not have allowed freewheel action.

Regarding the cold weather, I'm not sure what you're saying. But I say I think the cold weather is what masked the problem over the winter. I'm sure the belt tightened in the cold, allowing the pulley to have more tension. Once it warmed up, the pulley was once again allowed to slip and get progressively worse. The problem surfaced because the pulley failed. The weather only hid the symptoms.

OH, before I forget, I've read a post or two about jumpy serpentine belt tensioners. One of the first things I replaced while troubleshooting my problem was my serpentine belt tensioner (I thought the squeaking could be this tensioner). It was boucing around a lot and I thought it was failing. Sure enough, the new one made no difference. At that point, I feared one of the accessories was binding and causing the bouncing. I removed the belts to check the accessories and everything rotated smoothly. I didn't catch the slipping pulley at this point... must not have "failed hard" yet. Anyway, replacing the alternator pulley fixed EVERYTHING. The belt now glides smooth as silk... no more bouncing tensioner. To those with bouncing tensioners, you may be seeing the early signs of an alternator pulley failure.

Take Care,

Scott

 

[DPM]

Has anyone considered lubricating the pulley assembly? I'm guessing this is a roller-clutch of the same kind as used in motorcycle electric-start drivetrains...

 

[Stealth TDI]

Time to revive this thread. I've been getting TINY squeaks from time to time. After another eight months and 24,000-miles, my alternator finally gave out. The total mileage is 224,000-miles. I have a replacement onhand from NAPA (fastest source besides the dealer) and will swap it out tomorrow (pouring rain today). The replacement came with a solid pulley. I'll remove the freewheel pulley to check its condition before committing to the pulley swap. I hate to give up that pulley since it costs 75% as much as I paid for the rebuilt alternator. But I wonder if the solid pulley will work fine.

Thoughts?

 

[redtdi966]

where and how much did the tool that holds the larger outer splined part of the pulley cost where did you find it.

Also what did the rebuilt alternator cost, what was the symptom of the failed one? was it just bearings?

Thanks
Bruce

 

[paramedick]

$33 from Metalnerd. Picture near bottom of page on the link below.

http://www.metalnerd.com/cat05.htm

 

[matteas]

This may be a temporary fix of the pulley but I welded the inner section to the outer section after hearing the squeeks and crunching sounds of an impending pulley failure. I resorted to this after an atempt to replace the pulley only to strip the pulley bolt. It's working for now but I wonder how long the alternator will last.

 

[Stealth TDI]

Hi,

Bruce provided the info for the tool I used. Here's the PN in case anyone is confused: MN3400SET.

Regarding symptoms, the "BATTERY" light came on and the voltage displayed by my ScanGaugeII dropped to 11.9-volts. I shut off the ventilation, headlights, and stereo and continued on my 12-mile drive home without incident. I imagine the only things drawing current from the battery at that point was the ECU and fuel-cutoff solenoid. Anyway, with over 224,000-miles on the car, it could have been a voltage regulator or a set of brushes that went bad. I need the car up and running at almost all times and had very little time for figuring out the underlying problem. To me, it was worth while to just replace the alternator and not worry about the internals.

I got the part from an auto parts store called "Bap Geon" for $159.99 plus $90 core charge. When I peeled off the label on the part, it revealed a NAPA sticker. NAPA sells this part for $100 more. The alternator is marketed by "Talon" and is "remanufactured in the USA." My research revealed that this is still a 120-amp Bosch part. So I'm comfortable with the quality of my replacement part. And I'm REALLY comfortable about not paying the $600 MSRP.

Regarding the "temporary fix," keep in mind the diesel pulleys are designed to freewheel. That means the alternator can only be driven in one direction. I believe this extends the life of the alternator and eliminates voltage spikes during shutdown or quick decelerations of the engine (alternator is free to wind down independently of the engine). If I were in your shoes, I'd suck up the cost of the pulley and replace it soon. Good Luck!

Take Care,

Scott

 

[Uncle_Dave]

Have 03 Wagon. Had the Alt light flashing. Could measure the Voltage on the Lighter socket jumping, and the engine speed jumping. Bought a new belt to be on the save side. After three days it went away. I thought that some sort of object got stuck in there. I sprayed some belt adhesive on the belt, but it did not help.
Never did find the problem.

Uncle_Dave wb1fli

 

[treynolds]

Alernator Pulley Came Off While Driving...

Another response to a dead thread...

Whilst driving in the Portland, Oregon area the other day in my 2003 Jetta TDI, We heard and felt a loud THUNK!, and then noticed that the battery light went on and the power steering went out. Got stopped at our destination a few mile down the road aand found the alternator belt hanging free.

Harrowing drive back to Seattle later that day thru intense thunderstorms on battery alone, afraid to shut off the engine for fear would not start. Charged DEAD battery with our second car at office where we'd left it the day before (30 minutes) and got enough juice to finish trip home with lights. Could not have done this with a gasser; would have lost spark when the battery finally failed. TDI kept running with compression and glow plugs...

Anybody heard of an alternator pully just coming off while driving?

I don't have the resources or time to replace alternator myself; independent shop is doing it, plus the cracked idler pulley and chewed belt for $775 plus tax. They said the pulley couldn't be replaced by itself. That was before I read this thread. Too late now...

 

[LarryLymb]

Dealer charged me $771.21 to put on three different alternators after my alternator light went on. They finally replaced the pulley (N/C!!) to get everything going right. Took them a week to find the problem and they did pay for 2 nights hotel bill and for a week rental car while I was on vacation.

 

[treynolds]

I figure I did good by getting the car to my regular shop rather than having to stay out of state and have the repair done at a strange shop. Nice that the dealer helped pay for yoru expenses...

Called my shop after posting to this thread and they said that the bearings were seized and that it was the special pulley with the clutch. I told them I was just doing due diligence. They're a good shop and have never screwed us over...

 

[paramedick]

Common failure on the 03 model cars. Bad batch of pulleys.

 

[treynolds]

Common failure on the 03 model cars. Bad batch of pulleys.

Though I'm assuming that there is no recourse through my local VW dealer; just my tough luck, right?

 

[paramedick]

yup!

 

[Rickstdi]

Another response to a dead thread...

Whilst driving in the Portland, Oregon area the other day in my 2003 Jetta TDI, We heard and felt a loud THUNK!, and then noticed that the battery light went on and the power steering went out. Got stopped at our destination a few mile down the road aand found the alternator belt hanging free.

Harrowing drive back to Seattle later that day thru intense thunderstorms on battery alone, afraid to shut off the engine for fear would not start. Charged DEAD battery with our second car at office where we'd left it the day before (30 minutes) and got enough juice to finish trip home with lights. Could not have done this with a gasser; would have lost spark when the battery finally failed. TDI kept running with compression and glow plugs...

Anybody heard of an alternator pully just coming off while driving?

I don't have the resources or time to replace alternator myself; independent shop is doing it, plus the cracked idler pulley and chewed belt for $775 plus tax. They said the pulley couldn't be replaced by itself. That was before I read this thread. Too late now...

My car is sitting 120 miles from me as I write this.
What you described here is word for word what happened to me yesterday.
The only difference being is the belt is still in place but the pulley is on the side of the road somewhere. I'll post pictures later.
I had to come home to get the tow dolly and try to find an alternator.
This sure messes up a nice 4 day weekend.

 

[mh718]

alternator pulley

My weekend was wrecked too! Driving along the BQE in Brooklyn, a thunk, then no power steering, no ac, battery light on. Waited hours for a tow. Tow guy tried to put a new belt on for me and realized something wasn't right. Left the car at my mechanic instead (closed); he hoisted it up the next day and voila! No pulley.

Mine's an '03 with 74K. Sounds like this is a common occurrence, then?

 

[treynolds]

My weekend was wrecked too! Driving along the BQE in Brooklyn, a thunk, then no power steering, no ac, battery light on. Waited hours for a tow. Tow guy tried to put a new belt on for me and realized something wasn't right. Left the car at my mechanic instead (closed); he hoisted it up the next day and voila! No pulley.

Mine's an '03 with 74K. Sounds like this is a common occurrence, then?

Yes, it's common on 2003's.

Is there a reason why you didn't just drive the car home instead of waiting for a tow? You can drive a couple hundred miles on battery alone; better if you pull the breaker for the headlights.

 

[lkchris]

Couple items of confusion here:

1. Bentley manual for New Beetle conflicts with Metalnerd as regards tool to use to remove/retorque pulley to alternator. Metalnerd states its kit (Part MN3400) will arrive with 10 mm triple-square (XZN) bit. Bentley states tool required is normal hex bit, 6 mm.

2. Bentley describes in text the mult-point socket as tool 3340 but accompanying illustrations id the tool as 3400. Check in official tool catalog
http://buy.equipmentsolutions.com/eqs_va/Net/ItemDetail.aspx?PartNo=3400&qty=1&Desc=MULTI-TOOTH+ADAPTER&ListPrice=%2419.56&itemQty=87&group_id=4&group_name=3&cat_ID=&cat_name=&sub_cat_ID=&sub_cat_name=&item_id=513
confirms tool is indeed item #3400.

My next step appears to be to get NB on lift and verify tool required hopefully by using a mirror.

 

[cgeres@gmail.com]

WHY USE THE FREEWHEEL PULLEY ?
When a cylinder creates compression the engine is slowed down whereas the engine
accelerates when a cylinder is firing. This continual interaction causes the engine to run at
irregular speed which is, however not immediately evident.
This irregular running of the engine is transmitted from the crank to all parts
operated by the belt e.g. alternator, belt tensioner, etc..
These parts all have various levels of inertia, some are able to endure this
irregular running others are not.
O.E. names and numbers are used for reference purposes only.
TECHNICAL
UPDATE NO. 1
The alternator is the part which has the largest amount of
inertia,and is unable to endure this irregular running. This
means all other components have to carry a heavier
workload in particular the belt and the belt
tensioner. From time to time this requires the belt
tensioner to be adjusted in order for the belt not to slip.
By fitting the freewheel pulley the alternator is only
required to turn in one direction, which means the
belt is not subject to the heavy load and the result
is a smoother and more even running of the belt.

 

[onlyn8v]

Just so there is no confusion here. You can use any 120 amp alt with the proper ribbed pulley. My A3 has had a rebuilt Autozone alt on there for over 3 years. You DO NOT need to use the "special freewheel pulley"