Excessive drive belt wear

[Karanga]

About 3 weeks ago, I put a new alternator drive belt onto an isuzu 4le1 engine. I have done approx 25 hours motoring since then.

Replacing the belt required removing the water pump">raw water pump first, which required unbolting the whole pump from the block because there is no access to the adjustment bolts (dumb design etc etc).

Anyway, I fitted the new belt and tightened up the tension to nice and tight - certainly not guitar string tight.

As you can see in the photo, I now have significant belt fluff shed from the new belt. But it is not dry and loose fluff. It is more sticky.

Such a quantity of wear to me indicates that the pulleys may not be aligned. But how would I go about aligning these 3 pulleys, or checking their alignment, when they don't have similar thicknesses to put a straight edge across?

And is the fact that the fluff is more sticky than dry indicate that the stuff coming off is melted when it comes off?

Thank you for any suggestions
Tim

[rbk]

It’s most likely the alternator but don’t rule out the engine pulleys. Pull the belt and put a straight edge on the engine pulley’s to check for true, then adjust the alternator to match them assuming they’re good (most likely are) some have slotted holes to allow adjustment but bring a good stack of varying thickness ss washers to get it right. Also sight down the pulley’s to make sure none are crooked and not just misaligned.

[Karanga]

I understand what you are saying.

My problem is that the outside faces of the pulleys are each of varying thickness. The engine pulley, for instance has the raw water pump pully on the outside. So I don't know how to put a straight edge, or even sight across.
Plus, I only loosened the alternator enough to rotate it in its slide. Apart from pulling it up tight onto the new belt, I haven't changed its alignment (no bolts were removed, spacer washers removed/inserted etc)

[rbk]

Pick a benchmark (most proud pulley) and measure off the straight to the belt edge at each corespondent pulley. You can check for alignment by measuring around the face of each pulley. It’s nice to clamp the straight edge to the benchmark or have an extra set of hands.

[laika]

If you haven't done so recently, I would shine up those pulley surfaces with sandpaper or a brass wheel before moving onto other fixes. Especially if you happened to have just recommissioned the engine after a layup and changed belts in the process.

[coopec43]

There are a number of video clips. I've just installed a new generator so maybe I better look at them too.

https://www.youtube.com/watch?v=m5qHlgtQT8U

[capt jgw]

Quick and dirty way is to place a straight dowel in one pulley groove then rotate till it hits the other pulley. Should drop right into the other groove. Check top and bottom of all pulleys make sure they're not twisted.

[Fuss]

Is it a 12v or a 24v alternator?
What is the amperage?

[Alita49DS]

In my experience, and that of many others, including a lot of people who have addressed the issue here, V belts on marine engines are well nigh useless. Other than to generate a lot of dust before they disintegrate.

A much better solution is to bite the bullet and install a serpentine belt. This will involve replacing some pulleys but the result is infinitely superior.

I used Electromaax. https://www.electromaax.com/products...lley-upgrades/

The Canadian firm could not have been more helpful. They supplied to Gibraltar no problem so therefore anywhere. They were also a lot cheaper than some of their competitors.

The link that I have imbedded should answer most of your questions. If not, give them a call.

[Cadence]

I Don't believe all V belts are the same nor are the pulleys. Just because a belt is the same length does not necessarily mean it is a match. You might look into it.

[Rigdaddy]

Originally Posted by Alita49DS

... V belts on marine engines are well nigh useless. Other than to generate a lot of dust before they disintegrate.

A much better solution is to bite the bullet and install a serpentine belt. This will involve replacing some pulleys but the result is infinitely superior.

I agree that serpentine belts are superior in many applications, but not all. My V belt system has been doing a fine job for over 30years, and the cost to replace it with a serpentine is prohibitive. I believe that there are many others out there with similar situations.

[Alita49DS]

Originally Posted by Rigdaddy

I agree that serpentine belts are superior in many applications, but not all. My V belt system has been doing a fine job for over 30years, and the cost to replace it with a serpentine is prohibitive. I believe that there are many others out there with similar situations.

I suspect that it all depends on the load. A small engine with a small alternator might well work fine using a pair of tights.

As for prohibitive, that rather depends on your boating pain threshold. It cost me about £400 including postage from Canada to Gib. A couple of nights during the summer in a marina in the Balearics would set one back more! That is "ouch" for me but who am I to disobey the Admiral?

[Rigdaddy]

Originally Posted by Alita49DS

I suspect that it all depends on the load. A small engine with a small alternator might well work fine using a pair of tights.

As for prohibitive, that rather depends on your boating pain threshold. It cost me about £400 including postage from Canada to Gib. A couple of nights during the summer in a marina in the Balearics would set one back more! That is "ouch" for me but who am I to disobey the Admiral?

I suppose it depends on your definition of small; mine is a Volvo, 84 horse with a 120 amp Balmar alternator. Still, I would entertain switching to a serpentine system if/when I pull the engine for an overhaul.

[Captain Bill]

The drive belt looks too big imo. The alternator seems to be tensioned at the outer limit of the bracket. That is a long lever arm that can torque the bracket out of alignment if the belt is over tensioned and maybe even at normal tension.

[Cadence]

Does anyone really think reengineering his belt drive for a serpentine belt makes sense? Yep, the auto industry made an improvement but it was during engineering stage.
Where the hell would he find crowned pulleys to fit every thing? It is not practical.