When to change serpentine belt?

[JTinMO]

After running the 232 on LOTO all week, was cleaning up the boat last night after returning home and found there was fine dust in the bilge area at the front of the engine. It is not a lot, but is coming from the serpentine belt. The belt looks in fine shape, but I can pickup dust by running my fingers along the inside of the belt. I have no operational issues, just noticed it after running it all week. As far as I'm aware it's the original belt. Just turned 200 hours on the engine last week.

So question is - When should I change the belt? Does dust signal time to change, or is that normal to see dusting over time?

Lastly, anyone have a good step by step on how to properly change the belt? I have the OEM version on hand. Volvo Penta 8.1 Gi engine.

[Big Block Power]

Every Volvo I owned has had this issue. I only put hours on my boat in the garage so I don't have the belt issue so it will last a lifetime.

Really I would just keep a spare on the boat. Make sure all of the pulleys are lined up. I'm sure they are. Seems to be normal. If you see threads coming out of the belt or cracks change it. Just move the tensioner and the belt will come off.

[JTinMO]

Thanks BBP. Found the repair manual and it looks pretty straight forward. Is it as simple as the attached pic shows? Didn't think about removing the water pump but it looks like that's necessary for the change.

I will keep an eye on it and maybe do the change when winterizing this fall.

[Driller]

I changed mine over the winter, not sure when it was changed previously, but I had 2 yrs on it. Started shedding a “lot” of dust. Enough that the side and bottom of the bilge was pretty dark. No dust to notice this year.

[Big Block Power]

I guess you change it when you do the impeller

[smokymance]

I dont know if it helps anyone in the future, but after a few trial and errors, looking at the Gates fleet runner catalog, i got belt K060910HD to work on my 8.1L GXi...the fleetrunner belts are much stronger and last way longer than the "volvo" branded belts. About 1/3 of the cost too!

[Titaniumboy]

I’m still running my original belt with about 270 hours and 15 years. I also bought a Gates Fleetrunner belt and I plan to install it next month. The original belt still looks great and I’ll keep it as an emergency spare onboard.

How old was your existing belt?

My Gates belt size for my Merc 496 was very close to your VP with a part number of K060990HD.

[smokymance]

I run about 75-100hrs a season at least, so i try to do it every year or two just in case...over doing it? not sure, but the old style belts, gatorback looking OEM belts, always seem to have these little cracks on them after some time and they feel super soft, so I just toss them...have had great luck w the fleet runners or continental belts, so thats why i went this route.

[Krob1114]

One reason I like this site, (or one reason I don't), is that I'm always finding thing I should have done.
We put 400 hours on our 190 HP Volvo 6-cylinder, and I never change it.
We are now 200 hours on current Volvo 300, I and haven't thought about it.
Of course, I tool around like an old man. If the shoe fits!
Thanks for something else to think about.

[Big Block Power]

I changed mine after 20 years and it was pouring alot of dust in the bilge. If the factory one can go that long why not get another one

[bruceb58]

If your belt is shedding dust, that is indicating an alignment issue on one of the pulleys. Double check that none of the pulleys, especially the idler and tension pulleys ones have too much play in them. On my Lexus and F-150, I always changed the pulleys at the same time I changed the serpentine belt.

[Snowman8]

Go ahead and change the belt every year or every other if it makes you feel better but it’s not necessary. Dust is one thing but when they start to loose small chunks then it’s time.
My 2017 F350 has over 200,000 miles and just shy of 11,000 engine hours, yes that’s right 11,000 engine hours with the original belt that still looks good. I will probably replace it this winter when work slows down but a couple hundred hours on our boats is nothing...

[billk2632]

My Volvo V8-300 (2014) has marks on the tensioner that indicate when the belt has stretched to the point it should be replaced.

[DEcosse]

It looks like I need to replace mine on my 8.1 OSi which is same OEM part number as the 8.1 GXi
e.g. originally 3817290 now 21132390

20221006_151010_resized.jpg

20221006_150949_resized.jpg

It's clicking too and I think this is the cause (see my other thread of that subject in this forum) let alone it is shredding like crazy!

The question is what IS the correct after-market number?
I see @smokymance has K060910HD on the 8.1 GXi (but this seemed to be by trial & error?)
and @Titaniumboy has K060990HD on his Merc 496

I also found this - https://www.offshoreonly.com/forums/gen ... -belt.html
He physically measured his old one at 91.875 (91-7/8)
then bought 5060915 (which I presume would equate to K060915HD)

These are the dimensions I found for the parts numbers
Dayco 5060915 is 2325mm or 91.54"
K060910 is 2329mm or 91-11/16
K060990 is 2531mm or 99-7/8" so clearly the Merc Belt is quite a bit longer and not in contention for the VP application

So you can see in fact the 5060915 is 4mm (little over 1/8") difference (smaller) from the K060910 and he did say it was noticeably slightly smaller than the OEM so it looks like indeed @smokymance K060910 reference is the one to get!

[Big Block Power]

This was the belt I used to replace mine.