Need alternater decoupler help

Bob V · **Posted:** Tue Dec 09, 2008 10:49 pm

It took me a while to order it, then a while for it to get here, but IT WORKED! Wife is happy

. $66.00 is lots better than $400.00+. THANK YOU ALL FOR THE HELP!!!!!!!!!!

05infernoCRDL · **Posted:** Tue Dec 16, 2008 3:06 pm

bob...

did you need a pulley puller or did it just thread on... i just ordered my pulley yesterday.... my cap came off and threw clutch crap all over the side of the engine... my pulley has been chirping for a year... but the thing that did it for me the other day was i smellt burnt clutch under the hood and there was not enough power to run the head lights at full brughtness... they would come up then dim down then come up again

tonycrd · **Posted:** Tue Dec 16, 2008 3:22 pm

It just threads on.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Mine threaded on, but it needed a Miller Special tool, p/n 8433, unless I was willing to take the alternator apart. Even with the right tool, it was locked down pretty good and took a 24" extension bar to break it loose. Once loose, it comes off very easily.

The only gotcha is that the older decoupler (ends with an AC) is longer on the outer edge - this fits the 8433 tool perfectly. The newer decoupler ends with AE and is shorter on the outer rim - this causes the outer hex part of the 8433 to not fully engage. You have to be careful when tightening as it can slip and round the edges of the outer hex on the pulley.

05infernoCRDL · **Posted:** Tue Dec 16, 2008 9:56 pm

So I need a special tool for this?

kccrd · **Joined:** Thu Mar 08, 2007 10:35 pm **Posts:** 267

You don't need a tool to put it on just spin it on and replace the belt, it is always spinning to the right so it can't come off. I replaced mine about 20k ago works great. I just took the original off with a impact wrench just kept the inside from moving to release the pulley no special tool needed.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Yes, an impact wrench will brute force it loose, but it is helpful to realize that many CRD owners don't own impact wrenches, air tools or other general shop tools. If you don't own these, you'll need something to hold the alternator shaft still while you unthread the pulley. I do have an air compressor and an impact wrench, but since I had the Miller tool, I used it to reduce the stress of an impact wrench pounding on the alternator shaft and bearings. Another point is that my FSM shows the torque setting for the V6 engine alternator pulley at 81 ft-lbs, but nothing for the diesel. Judging from the force required to break mine loose, the factory torqued it down pretty tight. As was already stated, the normal engine rotation is in the tightening direction, so it shouldn't be an issue of working loose.

If I didn't have the Miller tool, I'd have tried the impact wrench also.

The special tool pops up on Ebay from time to time for about $15.

05infernoCRDL · **Posted:** Wed Dec 17, 2008 12:14 pm

I grew up with air tools so when I moved out that was one of my first investments... So I am golden. Thanks for the help!

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

I was inclined to replace the decoupler with a straight alternator pulley, until I watched this video. In the video, a Corvette V8 is shown with a straight alternator pulley and then a replacement decoupler installed. The tensioner is vibrating with a straight pulley and smooth when the decoupler is installed. This is with a V8 gasser, I think our large bore 4 cylinder diesel will benefit from the decoupler.

There are other whitepapers on the site about decouplers, including one TSB from Dodge, where they replace straight pulleys on 2003-2006 Dodge Cummins equipped trucks with decouplers.

http://www.tendeco.com/techtips.nsf/361 ... enDocument

tonycrd · **Posted:** Wed Dec 17, 2008 2:28 pm

I do have airtools but sold my 2cyl compressor when I moved to spain

So what did I do to get the old decoupler of:

Took an angle grinder and cut a slice of the old decoupler so I could bang on it with a chissel and hammer. Held the alternators axle with a 3/8 socket an extension so it couldn't spin.

2 bangs: came right of, no problem. The new one I tightened with one of these:

The outside of these 'pipes' is also a hex, grabbing the decoupler pretty good and since they are hollow the 3/8 socket with extention goes right through to hold the alternators axle.

You could also try to get it of with this method
(I used some K-mart rated 'pipe' so it didn't work.)

Bob V · **Posted:** Sat Dec 20, 2008 11:42 am

The two types of ends on the alternator shaft are internal hex (Allen wrench) or external hex (socket), mine has the external hex. Sense my decoupler was froze up I tried to brake it free by holding the alternator shaft with a deep socket/wrench and turning the decoupler with big channel lock pliers. The Decoupler unfroze and that was the end of that. Then I saw a shallow hole drilled off center of the face of the decoupler, still holding the alternator shaft with the socket I used a hammer and punch to turn the decoupler, that did the trick, no special tools. Put the new on back on hand tight, it will self tighten.

javert · **Posted:** Wed Jan 07, 2009 10:03 am

Do not tighten the decoupler by hand and never replace the decoupler with a solid alternator pulley. :roll:

The torque spec should be about 60 ftlbs. I know that it only turns in one direction, however, when the engine decellerates quickly and the decoupler overspins, there is a good chance that the decoupler could spin off if not torqued down properly! :shock:

If you are not going to use the proper tools to tighten to the correct spec, then at least give it a couple of rapps with the impact gun. The decoupler is available in the aftermarket for the CRD Jeep. You can purchase it at www.iat-usa.com. IAT is the master distributor for alternator decouplers in the aftermarket. Their phone number is 1-800-872-8890. If anyone has any questions about this product, don't hesitate to ask them here or PM me.

Javert.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Thank you. It's refreshing to see someone recommend using the proper torque setting. My FSM conveniently left out the torque setting for the diesel alternator but listed the 3.7L alternator at 81 ft-lbs. That suggests something more than hand tightening should be used on the diesel alternator, regardless of which way it turns.

javert · **Posted:** Wed Jan 07, 2009 10:43 am

I agree that torques are there for a reason and should be observed or at least as close as possible.

Hey, I wonder if Bob V was only ever driving his Jeep forward would he put his wheel nuts on hand tight? Just joking (sorry BobV) I just had to put that one in there.

Best Regards,

Javert

Bob V · **Posted:** Fri Jan 09, 2009 12:46 am

The decoupler WILL tighten itself if it is bottomed out first and you wont be able to get it any tighter than that (without doing damage to the shaft) .
If you knew ANYTHING about what happens when you torque something that has no room for bolt stretch (the decoupler to the alternator shaft) you would understand that (that might be why the FSM doesn't have a torque value for the diesel), and the FACT that it can NOT back off (remember it only drives one way).
I belong to many different automotive forums and the one biggest problem is people that read a few posts become experts. I was an ASE certified mechanic at the age of 20, have 2 years of automotive tech at college ( top in the class) and have NEVER had anyone else work on ANY of my vehicles in my life (48 yrs) yet now I know NOTHING because some guy that cant change his own oil can read a post on his computer.
BTW the Jeep is still running!!!!!!!!!!!!!!!!!!!!!!!!
And I DO tighten the lug nuts! and I KNOW and UNDERSTAND what is happening to the wheel studs, the wheel and the hub as it is being tightened, DO YOU?

tonycrd · **Posted:** Fri Jan 09, 2009 8:27 am

Bob, think of your bloodpressure

I thought al that too but decided not to respond.

Anyway, they don't mean nothing by it, take what is usefull to you. :wink:

javert · **Posted:** Fri Jan 09, 2009 8:56 am

Gents,

For the record, every other car manufacturer has a torque spec for installing an alternator decoupler. Maybe Mopar got it wrong by not including it in their FSM for the liberty? Have you ever know Mopar to be wrong on something? If you take look at the 2001-2006 Chrysler minivan (3.3L and 3.8L engines) FSM there is a torque value and there is also a special tool available at the dealer to perform the torquing job properly. To properly torque this product you need to hold the decoupler shaft with one tool and turn the alternator rotor with the other tool. This will give the appropriate bolt stretch for the threads within the decoupler shaft.

Javert

tonycrd · **Posted:** Fri Jan 09, 2009 9:05 am

But you would need some really fancy special tool kit to be able to torque wrench the decoupler on our CRD's. Has anyone who is determined to torque it to specs have any hands on experience with this part?

It doesn't have a bolt...or a nut.

I do not see how...other then ramming a screwdriver through one of the cooling slots in the alternator body to block the rotor.

Kinda beats the purpose :shock:

JAVERT: stop editing your post before I can answer darnit :lol:

Ok you are right, with a special tool you can. Now, mine has been on little over hand tight for 50k Km...I don't expect it to fal of anytime soon.

Uffe · **Posted:** Fri Jan 09, 2009 9:11 am

Bob V wrote:

The decoupler WILL tighten itself if it is bottomed out first and you wont be able to get it any tighter than that (without doing damage to the shaft) .
If you knew ANYTHING about what happens when you torque something that has no room for bolt stretch (the decoupler to the alternator shaft) you would understand that (that might be why the FSM doesn't have a torque value for the diesel), and the FACT that it can NOT back off (remember it only drives one way).
I belong to many different automotive forums and the one biggest problem is people that read a few posts become experts. I was an ASE certified mechanic at the age of 20, have 2 years of automotive tech at college ( top in the class) and have NEVER had anyone else work on ANY of my vehicles in my life (48 yrs) yet now I know NOTHING because some guy that cant change his own oil can read a post on his computer.
BTW the Jeep is still running!!!!!!!!!!!!!!!!!!!!!!!!
And I DO tighten the lug nuts! and I KNOW and UNDERSTAND what is happening to the wheel studs, the wheel and the hub as it is being tightened, DO YOU?

I happen to frequent forums for shrinks and from reading their posts I can immidiately identify that you feel angry.

javert · **Posted:** Fri Jan 09, 2009 9:20 am

There are three basic ways to do this.

1) An Impact gun with torque stick.
2) Half assembled alternator (rear housing removed) rotor held in a vice and then use a torque wrench.
3) The proper Insallation tools and a torque wrench.

Method 1. You will however need to use the correct bit/tool to engage the decoupler shaft.

Pros: You can remove and install clutch pulleys on alternators that dont have an installation feature in the alternator shaft.
Cons: You will not achieve the correct torque. It may be close.

Method 2. You will also need to use the correct bit as well as a torque wrench.
Pros: You can remove and install clutch pulleys on alternators that dont have an installation feature in the alternator shaft.
You don't have to buy all the different installation tools. (just some of them).
You can achieve proper toruqe.

Cons: You will have to disassemble the alternator. (remove rear housing)
You will need a vice to hold the alternator rotor.
You risk damaging the alternator rotor when clamping in the vice.

Method 3. You will also need to use the correct installation tools as well as a torque wrench.

Pros: You can safely remove and install clutch pulleys on the bench as well as in the vehicle saving the re and re time of the alternator (not all cases due to space constraints).
You can achieve proper toruqe and have full control of not damaging the threads.
Cons: You have to buy all the different installation tools.On alternators that do not have a feature for the installation tool to engage in the alternator shaft, you will need to use an alternate method.
In my opinion Method 3 is the absolute best way to do the install.

Hope this helps.
Javert.

I have pictures of all of these methods but I am having trouble attaching them to this post. If you would like them, PM me with your email address.

Need alternater decoupler help

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