The hidden differences in Heavy Duty Serpentine belt length can be a royal pain sometimes.

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I upgraded the alternator in my 2016 Honda CR-V EX with 2.4 L gasoline engine to an Apex 200 Amp at idle and 350 maximum at a somewhat higher engine RPM. This high output alternator comes with a smaller pulley on it so it spins faster to aid it it being able to make more current, and one of the recommendations is to install a slightly shorter serpentine belt to take up the extra slack it creates. It is recommended that the new belt be 1/2 inch to 1 inch shorter then the original.

The original is 56.5 inches long.

NAPA does not list any in the required shorter range, so I called Summit.

Summit list a 55.5", 55.84" and 56.2". Since the 55.84 is in-between the recommended range of 1/2 to 1 inch shorter that is the one I ordered.

The one they sent me is an ACDelco Professional part no. 19194127 K070553HD made by Gates, and it is a heavy duty serpentine belt.

When I put a 17mm wrench on the hex had stud to move the tensioner, the amount of slack in the original looks like something that is 0.66 inch shorter would go on without any problem. But when I try to put it on, there is no way it is going to fit. It ends up being too short to get it to go on all the pullies at the same time. I had the tensioner moved to so much that I could tell it reached a hard stop on movement and would not retract any further. I tried making the water-pump the last pulley that it went on because the belt rides on the backside for that pulley and there is no lip to have to go over. But still it is too short to get the last amount of the belt on. Regardless of what pulley I use as the last one for the belt to go on, it is just not long enough.

The original belt only has 32,000 miles on it, and works good enough for now, but I want to put a on a new slightly shorter belt to be sure the belt is plenty tight enough when I load down the new alternator to power the high-reliability 2200 Watt Mean-Well 12 VDC to 125 VAC inverter I will be connecting to it.

It took me a while to figure out why this new belt that is only 0.66 inch shorter will not go on. Along with the already 0.66 inch shorter difference, I am working with two other things that make the over-all length even shorter than the original. 1) the new belt is not seated (worn in at all) and 2) this HD belt is much thicker then the original. At first the difference in thickness would not seam to be something that can cause a problem, but because on most pullies the belt rides on the side with groves, and on the big pulley of the water-pump the back-side of the the belt is against the pulley the difference in thickness combined with the large radius of the water-pump pulley uses up considerable more length of the belt, resulting it the over all length being too short for it to fit.

The bottom line is that thicker serpentine belts such as HD belts, because they also have to ride on some pullies that are against the back side instead of the side with groves, result in more of the belt length being used up, and this leaves significantly less over-all length of the belt to fit on the rest of the pullies.

In this case the difference is enough to make it impossible for a slightly shorter but HD belt to fit on all the pullies at once.

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I am thinking of getting an original length serpentine but in a HD and let the reduction of length from back of the thicker belt going around the water-pump provide the reduction of length that this set-up requires.


I just though I would pass this along, so you know that if you use a new HD serpentine and it has to have its back-side ride on one or more pullies as most systems do. So you know to expect the over-all working length to come up shorter that what the listing for the belt says it is.
 
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Interesting story similar to this that happened at my work. A few weeks ago a customer brought in a 2018 Explorer on a Saturday with a battery light on. Tech confirmed the alternator was smoked. I looked it up and the cataloging listed 2 possible alternators for this vehicle, a 220A and a 230A. We had the 220A in stock because it is commonly used on the Police Interceptor Explorers. But according to the Build of Material for the vehicle, it actually came with the 230A one. Per the customer, we had to have it fixed that day, no exceptions. Now bringing a car in on a Saturday severely limits our options as to acquiring parts, even aftermarket. I crossed the part number with the usual suspects and none had the 230A in stock. Did the quote for the correct 230A Motorcraft unit and we would have it Monday.

Next thing I know the Explorer is being given back to the customer. They bought an alternator from I think Autozone, and service installed it. Problem was, they didn't show having the correct one in stock, so I know what they did/didn't do, but whatever, ignore the Ford parts person with 15+ years of experience.

Customer brings the vehicle back during the week for a noise in the front end. Another tech comes in to get a price on an alternator because this one isn't charging. I reprint the same quote and off they go. Tech comes back with the belt and asks me to look up a belt. I look up the one it calls for, JK6-457A, and that is the same as the one on there. Tech says it is too long. On a whim I get the 220A alternator we have in stock and the pulley size is the same as the one on the vehicle. Double check my sales history on the 220A alternator and the belt most commonly sold with is is a JK6-455, so about 1/5" shorter. Tech tried that belt and it worked perfectly and the noise was gone.

Needless to say the customer was livid, especially with our comments on the RO on both the parts and tech side indicating that the customer's supplied part was wrong.
 

wtd

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I just put a HD AC-Delco belt on my 98 Chevy K1500 with the 5.7L and I barely got it on. It was the right number because I double checked. None of the other belts I've used in the past was that hard to get on.
 
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I realize this thread is a little older but it came up as "suggested"....

Per the customer, we had to have it fixed that day, no exceptions.
Or what ? I'm guessing the service department is only open (officially) shorter hours (i.e. 8-12) and they probably can't get to another dealer in time, not to mention be told "we can't do it today".

Also, do the parts stores typically only deliver on weekdays ? You said getting aftermarket parts was harder on a Saturday.
 
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Or what ? I'm guessing the service department is only open (officially) shorter hours (i.e. 8-12) and they probably can't get to another dealer in time, not to mention be told "we can't do it today".

Also, do the parts stores typically only deliver on weekdays ? You said getting aftermarket parts was harder on a Saturday.
I love the customers that give ultimatums because well that's why I work in parts and am known for not sugar coating anything. I have no problem saying "ya that's nice so in the real world these are your options." We are 8-4 on Saturday with a 1230-1PM lunch break as opposed to 8-5 during the week.

So during the week we can get parts from more sources. On Saturday we are basically limited to Fast Undercar (who have about a 65% wrong part sent rate), Autozone, and O'Reillys. During the week we have IMC/Parts Authority who have a ton of brand options. We can also get Motorcraft parts same day from our region's Motorcraft distributor, although sometimes that means an extra 10% on the parts price because of reasons. I do all the ordering and stock replenishment ordering. Our stocking levels are based off of sales history. Although there are some parts I force to stay in stock because in my years of experience, they will sit with no movement for 11 months, then we sell 4 in a day. Namely the F81Z-9A153-AA fuel drain valves for 7.3 diesels.
 
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If the 56.5" belt goes on and and tensioner is in the middle of it's travel then I wouldn't worry any more about it.

I know when I've purchased belts here, there's a reference. Usually something like "4PK690" where the "4PK" means 4 ribbed and the "690" is the length in millimetres. I measure the length of the required belt by running a piece of string with the tensioner retracted around the belt system and then measuring the string. Buying a belt is easy then!
 
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I know when I've purchased belts here, there's a reference. Usually something like "4PK690" where the "4PK" means 4 ribbed and the "690" is the length in millimetres.
Yeap, I don't know the specifics (anyone can look it up) but many belt types have a industry-standard naming scheme.
 
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Try dealing with V-belts. A V-belt for a given application can have 2-3 different lengths specified depending on the manufacturer of the belt. Just hope that the catalog is right.
 

JimPghPA

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I got the one that Summit has that is 0.3 inches shorter than original and not HD. It went right on. And the tensioner is closer to the middle than with original.
 
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Try dealing with V-belts. A V-belt for a given application can have 2-3 different lengths specified depending on the manufacturer of the belt.
Do belt manufacturers look at applications and factor in that many (??) are using adjustable/hydraulic tensioners that allow a little bit of length variation ?
 
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Do belt manufacturers look at applications and factor in that many (??) are using adjustable/hydraulic tensioners that allow a little bit of length variation ?

I'm sure they do. They also probably try to consolidate as many applications as they can.

It just seems that reports of incorrect V-belts are a lot more common than reports of incorrect serpentine belts.
 
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I'm sure they do. They also probably try to consolidate as many applications as they can.
Exactly, consolidating applications is huge for them. They have an existing 6-groove V-belt that's 67.50" long and there's an application with a hydraulic tensioner that nominally specs a 67.13" long belt, they're going to use the existing one !
 
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