ADP's (Alternator Decoupling Pulleys)

[mwilson]

It's a wasted day when you don't learn something. B.G. Smith had PM'd me asking if our 3rd Gen trucks had a decoupling pulley. They do.

I started researching the subject and have learned quite a lot about the little buggers. I also had a strange noise in my 2002 Town and Country, sounded exactly like a bearing knock. At 110,000 miles I found that to be highly unlikely so I had planned to disconnect the drive belt to see if I could pin it down.

In the process of researching ADP theory I found several threads on a Town and Country forum describing the strange noises that a failing ADP can make. i'm thinking "What's the frigin' chance that my van could be suffering from that?".......

So armed with a new ADP and as a back-up a complete alternator with pulley in case something went wrong or the alternator itself was indeed bad I had at it yesterday. I also purchased a Lisle ADP removal tool set for $39.00. You can't remove the pulley without a special tool set.

I am out of time tonight, I will add pictures to this tomorrow night. For now, here's a little reading....http://www.gates.com/products/autom...drive-system/alternator-decoupler-pulleys-adp

 

[B.G. Smith]

Thanks Mike, things are a lot clearer now. Gotta get me one of those kits. bg

 

[AH64ID]

Interesting. Do all 3rd gen's have them?

I had my alternator out two winters ago and thought it was a standard pulley, but I will look at it again tonight.

 

[mwilson]

That's a good question. I'm at a different store today and I don't know if I can jump into my Nexiq program from here.If I can I will look up an 04 and an 05 just to see.

 

[JR]

I had the privilege of learning about these on the wife's TDI. I ended up rebuilding the entire altenator while it was apart, since I had to remove half the front end (and most of the skin off my knuckles) to drop the dang thing out.

VW's tool looks something like this

http://www.handsontools.com/product...ArIrrfg2wSCVcj4oHGZZzGjjjTRm0PRl1waAjg28P8HAQ

 

[cerberusiam]

Not all trucks have them, that started somewhere in the later 5.9 era as a TSB for belt chirp. Updated alternators may include them as a default or option now.

 

[mwilson]

Mine was born with it so maybe '06 was the beginning??? I will research when I get back to home base.

The little buggers can cause some issues when they fail depending on HOW they fail. Noises, no charge or erratic charge conditions, etc...

I am wondering if a bad one could stress tensioners, idler pulleys, even water pumps??? Not saying it for sure but just wondering.

These ADP's are not really on our trouble shooting radar so far.

As far as the mini-vans go the ADP is up for replacement anytime that the belt, tensioner and idlers are changed.

 

[B.G. Smith]

The one I changed on the 07, I had to remove a panel under the rt. front wheel well to get to the tensio0ner , then I had to remove the EGR valve to get the alternator out. Engine was a 3.5L. bg

 

[mwilson]

I was lucky, my 3.8 does not have the EGR junk in the way. Neither does my 3.3. The plastic sheild has to come off underneath regardless but makes threading the belt and working with the tensioner pretty easy.

 

[B.G. Smith]

I just priced a pulley at local auto parts, $147.00 plus some change. Might be best to just do the whole alternator. bg

 

[seafish]

Dealer put an ADP on my 2005 after I brought it in for throwing the belt once under warranty.