Alternator clutch pulley warning

tonycrd · **Posted:** Sat Jan 17, 2009 6:55 pm

Maybe we should all keep a hammer and some nails handy in our car?

So when it dies we can bang some nails in the decoupler to prevent it from free wheeling?

BlackLibertyCRD · **Posted:** Sat Jan 17, 2009 6:58 pm

tonycrd wrote:

Maybe we should all keep a hammer and some nails handy in our car?

So when it dies we can bang some nails in the decoupler to prevent it from free wheeling?

Now that is some back yard mechanicing-ging 4 ya! :-)r

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

but it's not a bad idea to lock it up if you can in an emergency. If that decoupler goes bad one night, I wouldn't hesitate to shoot a tube of instant super glue into it before I'd walk home in the cold. It's already ruined when it won't lock up anyway.

warp2diesel · **Posted:** Sat Jan 17, 2009 9:33 pm

The alternator decoupling pulley contains a part inside that goes by the following names:

1) Sprag Clutch

2) Over running clutch

3) Back Stop

Engineers love to come up with names that are not standard.

All of the items above contain oval or egg shaped needle bearings between the two races that lock in one direction and allow free movement in the other direction.

A ratchet with Pawls would work, but would be noisy and self destruct much sooner.

As a general rule engine start is stress full (more so in cold weather) on the alternator decoupling pulley. I would bet that a CRD doing Pizza deliveries would trash out the alternator decoupling pulley sooner than some one doing long drives towing a trailer.

Hope this helps any one who does not understand how it works.

KeighJeigh · **Posted:** Sat Jan 17, 2009 9:45 pm

Ranger1 wrote:

Quote:

Once it completely decoupled last night, it no longer spun the alternator and the lights dimmed dramatically until the engine stalled.

Just out of curiosity, about how long did your battery last before the engine stalled? I hope I don't need to use that info some day, but it might come in handy.

About 20 minutes as I was running the defroster and headlights (it was cold, foggy and icy). It probably would have lasted longer but I'm sure the battery charge was already seriously compromised by the poor charging that has likely been going on for a while now.

KeighJeigh · **Posted:** Sat Jan 17, 2009 10:03 pm

tonycrd wrote:

Maybe we should all keep a hammer and some nails handy in our car?
So when it dies we can bang some nails in the decoupler to prevent it from free wheeling?

I actually tried this using some 5 minute epoxy I happened to have with me but I couldn't squish it into the space between the inner and outer sections. I looked around for something to wedge into it and even considered hitting it with a rock to bend the outer pulley and jam it into the inner section. But it is aluminum on stainless steel so it probably didn't have a chance of working....and I really didn't want to screw up the alternator too. Perhaps super glue would work, but there is a heck of a lot of shock involved and with all the dust and grime inside the unit, it probably wouldn't engage the metal very well.....although maybe some carb cleaner sprayed in there would help.

Probably best to just replace the thing immediately after it starts making noise.

--------------

I just got back from running all over town looking for something that might work. Nobody has any idea what I'm talking about concerning the Miller tool nor did they have any suggestions on how to get it off. Even the folks at the dealer shrugged their shoulders. (thin weekend crew) They would likely just replace the alternator or send it to an alternator shop.
No store open on Saturdays carried a 17 mm impact hex so I'm going to make my own by sawing off a section of a regular hex wrench and sticking it into a 17 mm impact socket. If the hex key doesn't shatter, it might work..... :roll:

Unfortunately, since both cars are down, I have to do whatever it takes to fix this.

Question: If I have to split the alternator to hold the shaft, I assume there is a square section on it? I can't imagine people are actually putting the round shaft into a vice. :shock:

warp2diesel · **Posted:** Sat Jan 17, 2009 10:08 pm

Just don't loose your brushes or springs.

BTW: You may find that older alternator brushes or power tool brushes from ACE Hardware will work if you have to replace them. I have put GM brushes in Bosch alternators several times. If they are too big, use good medium sand paper.

When the brushes in my Doug Nash/ US Gear overdrive wore out, brushes for a Porter Cable power tool fit great and were higher quality then OEM.

Good Luck Chris

Bob V · **Posted:** Sat Jan 17, 2009 10:54 pm

KeighJeigh wrote:

tonycrd wrote:

Maybe we should all keep a hammer and some nails handy in our car?
So when it dies we can bang some nails in the decoupler to prevent it from free wheeling?

I actually tried this using some 5 minute epoxy I happened to have with me but I couldn't squish it into the space between the inner and outer sections. I looked around for something to wedge into it and even considered hitting it with a rock to bend the outer pulley and jam it into the inner section. But it is aluminum on stainless steel so it probably didn't have a chance of working....and I really didn't want to screw up the alternator too. Perhaps super glue would work, but there is a heck of a lot of shock involved and with all the dust and grime inside the unit, it probably wouldn't engage the metal very well.....although maybe some carb cleaner sprayed in there would help.

Probably best to just replace the thing immediately after it starts making noise.

--------------

I just got back from running all over town looking for something that might work. Nobody has any idea what I'm talking about concerning the Miller tool nor did they have any suggestions on how to get it off. Even the folks at the dealer shrugged their shoulders. (thin weekend crew) They would likely just replace the alternator or send it to an alternator shop.
No store open on Saturdays carried a 17 mm impact hex so I'm going to make my own by sawing off a section of a regular hex wrench and sticking it into a 17 mm impact socket. If the hex key doesn't shatter, it might work..... :roll:

Unfortunately, since both cars are down, I have to do whatever it takes to fix this.

Question: If I have to split the alternator to hold the shaft, I assume there is a square section on it? I can't imagine people are actually putting the round shaft into a vice. :shock:

I did mine in lees than a hour with the alternator on the engine, that included a new belt. Still running, even though others think that it should have blown up by now

KeighJeigh · **Posted:** Sun Jan 18, 2009 1:54 am

I found a way to get the pulley off VERY easily in about 30 seconds with no special tools.
Simple concept: The old pulley is already broken so you don't need to play nice with it.
Take out the alternator, place the end of the outer casing of the pulley into a vice and squish the hell out of it until it clamps down onto the inner part. This keeps the pulley from spinning so you can put a 10mm socket onto the alternator shaft and off it comes. (remembering, the pulley is a regular right hand thread but as the alternator shaft faces you, it is treated as a left hand thread so unscrew it clockwise) I also sprayed a bit of penetrating oil into the threads 10 min before I tried it.

Add a bit of penetrating oil, crush it in the vice and then use a 10 mm socket to turn the alternator shaft clockwise

Yep, it's crushed. Oh well.

HOWEVER, you do not need to force your vice as hard as I did. This was just part of a long string of ridiculous happenings this evening.

--------------

Now the broken CRD #1 is fixed, broken CRD #2 is stuck on the side of the road.
I started a different thread on that one. I'm beginning to think these cars should pull a trailer full of spare parts, a full diagnostics lab and a certified diesel mechanic just to go to the friggin store. This is getting utterly ridiculous. UPDATE: I got it back - in a weird way.[/img]

hatchetman · **Posted:** Sun Jan 18, 2009 4:21 pm

Does the clutch pulley have a dust shield or cover on the front of it? I just looked at mine and it doesn't look like your pictures.

warp2diesel · **Posted:** Sun Jan 18, 2009 5:19 pm

Yep dust plug.

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

I'm guessing a long pipe handle was involved with that vise. If you did that with your bare hands, you don't need any special tools. You could tear it loose with one hand.

:shock:

DnA Diesel · **Posted:** Sun Jan 18, 2009 5:56 pm

Ranger1 wrote:

I'm guessing a long pipe handle was involved with that vise. If you did that with your bare hands, you don't need any special tools. You could tear it loose with one hand.

:shock:

True!

warp2diesel · **Posted:** Sun Jan 18, 2009 6:28 pm

....that made it weak.

Now we know what they do with the cast Iron that is too poor to make brake rotors out of. :lol:

KeighJeigh · **Posted:** Sun Jan 18, 2009 6:43 pm

hatchetman wrote:

Does the clutch pulley have a dust shield or cover on the front of it? I just looked at mine and it doesn't look like your pictures.

My wife's 06 does have a dust cover. Mine does not. (never did) Nor does the new one.
Not sure if it matters.....can't imagine that it really does any good since it isn't actually protecting anything unless it somehow sealed the gap between the inner and outer sections.

KeighJeigh · **Posted:** Sun Jan 18, 2009 6:47 pm

DnA Diesel wrote:

Ranger1 wrote:

I'm guessing a long pipe handle was involved with that vise. If you did that with your bare hands, you don't need any special tools. You could tear it loose with one hand.
:shock:

True!

Well, it wasn't THAT long of a pipe! (only 18") It's the same one I've used many times before. True, this time I was a bit more agitated and in a more "persuasive" mood.....but still... :roll:

gmctd · **Posted:** Sun Jan 18, 2009 6:56 pm

Looks like a haborfreightdotcom vise :roll:

, tho clamping the workpiece fully offset from center like that does put undue stress on the rotatable barrel-slide section, being a "C" rather than a full 360* "O" casting

There's your DCJ p\n in plain sight on the new sheave on the right in the pic, even the AE revision level.

This over-running clutch should have a coil-wound spring as the brake, as the hub or sheave requires only single-direction drive and release, with no 360* movement or reversing rotation -
- used in typewriters, printers, xerox machines, hand-tools, Diesel alternator sheaves, etc

Another type for full 360* rotation in both CW and CCW directions, the sprag clutch, has round bearings in inner race with channeled ramps, having accordioned-tab springs forcing them up the ramps against the outer smooth race - the bearings lock the races when outer race rotates in the direction of the ramps or inner race rotates in the opposite direction - releasing when either race rotates opposite it's original locking direction - used universally in automatic transmissions and other transmission equipment - 545RFE is chock full of 'em, and the torque convertor has one in the stator.

KeighJeigh · **Posted:** Sun Jan 18, 2009 7:14 pm

gmctd wrote:

Looks like a haborfreightdotcom vise :roll:

, tho clamping the workpiece fully offset from center like that does put undue stress on the rotatable barrel-slide section

There's your DCJ p\n in plain sight on the new sheave on the right in the pic.

This over-running clutch should have a coil-wound spring as the brake, as the hub or sheave requires only single-direction drive and release, with no 360* movement or reversing rotation -
- used in typewriters, printers, xerox machines, hand-tools, Diesel alternator sheaves, etc

Another type for full 360* rotation in both CW and CCW directions, the sprag clutch, has round bearings in inner race with channeled ramps, having accordioned-tab springs forcing them up the ramps against the outer smooth race - the bearings lock the races when outer race rotates in the direction of the ramps or inner race rotates in the opposite direction - releasing when either race rotates opposite it's original direction - used universally in automatic transmissions and other transmission equipment - 545RFE is chock full of 'em, and the torque convertor has one in the stator.

The vice is about 14 years old and was the cheapest one I could find of that size - I think I got it at Sears although as you pointed out it appears to be a DCJ at heart. At the time, I just couldn't justify spending $200 on a hunk of metal that looked just like another hunk of metal for $50. Besides, my "shop" consisted of a plastic tarp strung over a table in a gravel driveway of a rented house - so I wasn't picky.
If I get the time and if my DCJ-approved metal saw will allow it, I will cut the outer section off so we can have a look inside and perhaps even see the failure.

gmctd · **Posted:** Sun Jan 18, 2009 7:21 pm

Not being critical - just noting the possible source - my big red one, just like it (butcept not broke!) with similar chronology, is HFDC - back then, they were from Taiwan or India\Pakistan, with Taiwan being better casting material - most of the current Chinese stuff is even better

KeighJeigh · **Posted:** Sun Jan 18, 2009 7:53 pm

gmctd wrote:

Not being critical - just noting the possible source - my big red one, just like it (butcept not broke!) with similar chronology, is HFDC - back then, they were from Taiwan or India\Pakistan, with Taiwan being better casting material - most of the current Chinese stuff is even better

I'll probably just look for one on Craigslist this time around...

Alternator clutch pulley warning

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