Purchasing a matching pair of fan belts...

[MikeP]

Is this no longer possible?

In redoing the block heaters, which required removing the alternators and brackets, I decided to install new belts (Gates 7470) and I checked around for two matched pairs. Several shops looked at me like I was nuts. The local Napa store said they hadn't actually seen a matched set in years. He explained that since any given number belt might come from anyplace from China to Brazil to Mexico, they can vary considerably - not enough to matter for single belt fitment but enough to make one belt loose on a dual setup. I checked at the local Diesel shop (where I bought the heaters). They suggested I try Napa. ;)

I bought 4 7470s and tried to match them as best I could but on both engines, one belt is noticeably less tight than the other. It's not TOO loose for proper operation but it's not as tight as it should be.Over time the tighter on will stretch a bit and then if they are retensioned, they should be about the same. So I guess nowadays, obtaining a matched pair of belts means running/wearing them in to get them to match.

[rsmith]

You have fans on your engines??? Just kidding! Napa pretty much sucks these days. It's always "all the parts you don't need but we can order it for you" you could probably order them from WW Grainger or go to a Power transmission outfit that sells bearings and drives for industrial stuff.

[captddis]

The best you can do is match the batch numbers. Don't use NAPA belts for the alts, they will shred in less than 10 hours. Get the Goodyear or Bando.

[Bill Allen]

Haven't seen matched belts in years. The belt people claim their specs are so good it's just not done anymore. Sadly their wrong i've seen the same thing. Bill

[GJH]

The best you can do is match the batch numbers. Don't use NAPA belts for the alts, they will shred in less than 10 hours. Get the Goodyear or Bando.

Intersting you say that Dave, I always thought the Gates belts were as good as it gets. On the big engines, rather than sweat that out, I have DD house brand, not sure who they use but this set is still looking good after 1000 hours.

Getting ready to pre-emptively switch them out, so this is interesting info/topic. So here is my really dumb question, not having had to deal much with belts in my life: Do they have a shelf life? I have a spare set of DD belts that have been instorage on the boat for at least 6 years. Sounds like a dumb question to me because the ones on the engines are fine, but so many things seem to be "use it or lose it" I'll play dumb anyway.

[luckydave215]

You can still get matched sets of belts, industrial machinery use them all the time.
But they're expensive.

[MikeP]

"Don't use NAPA belts for the alts, they will shred in less than 10 hours. Get the Goodyear or Bando."

They (Napa) had Gates belts - actually they had to order them but got them later in the day. Are the Goodyears or Bandos better than the Gates? Gates USED to be what we used for just about any belt/hose application but it's been 7-8 years since I was doing that stuff on a daily basis. I don't want to sound like a curmudgeonly old guy (though I am) but it seems like a lot of brands that used to be top notch are now just slightly above the junk level. :(

[captddis]

George,
I always liked the Gates Hd belts too. They just do not last anymore. In a pinch I will use them on a generator or gas engine and they are ready for replacement in a couple years. The cogged belts always crack at the thin part.

For some reason the big alternators really kill them. Every big Alt that I put the napa belts on have shredded them.

One case in point, When I rebuilt my port engine, the first set of napa belts shredded in about 6 hours. I borrowed a car and had to get another set of Napa's they lasted a little over 10 hours.
Then I put a set of bando's on and 6 years later all is well.

As far as shelf life, my unscientific gauge for spare belts is when they are stiff, they get tossed.
Every time I installed someones stiff spare, it fails quickly.

[GJH]

George,
I always liked the Gates Hd belts too. They just do not last anymore. In a pinch I will use them on a generator or gas engine and they are ready for replacement in a couple years. The cogged belts always crack at the thin part.

For some reason the big alternators really kill them. Every big Alt that I put the napa belts on have shredded them.

One case in point, When I rebuilt my port engine, the first set of napa belts shredded in about 6 hours. I borrowed a car and had to get another set of Napa's they lasted a little over 10 hours.
Then I put a set of bando's on and 6 years later all is well.

As far as shelf life, my unscientific gauge for spare belts is when they are stiff, they get tossed.
Every time I installed someones stiff spare, it fails quickly.

Thanks Dave. So my next dumb question is, how do you determine "stiff"? And remember, this is a family forum. But seriously, I'm curious. Maybe I'll just buy new ones from DD and keep the stored ones as emergency spares.

I have used the Gates cogged belts (from CarQuest) on the Onan; since you have to take off belt to change the raw water impeller on the dang thing, I replace it about every 600 hours "while we're in there" and it seems ok, but that is a much smaller application with less horse power.

[bobk]

I sure hate to hear that Gates belts are not the best any more. I put a pair on the Vickers pump that drives the Naiads several years ago and they still look OK, but I am seeing 'belt dust' in the vicinity. No cracks on the belts.

Where do you get Bandos? Never heard of them. I might just swap them out before heading to Florida next month.

Bobk

[captddis]

http://www.daltonbearing.com/suppliers/bando-belts.aspx

[SKYCHENEY]

What about a banded set?

http://www.vbeltsupply.com/ecommerce/media/catalog/product/cache/1/small_image/170x/9df78eab33525d08d6e5fb8d27136e95/2/_/2.jpg

It depends on the spacing but if you go to an industrial supply place, they usually can come up with something.

[Plan B2]

A timely topic for me. I just replaced the two alt belts on my starboard engine with Napa product. If they fail quickly I'll come back and post it here.

[MikeP]

" I just replaced the two alt belts on my starboard engine with Napa product. If they fail quickly I'll come back and post it here."

Well, same here. I had purchased the Gates belts from Napa before posting about matched belts so we'll see. But OTOH, both engines/alternators had Gates (7470) belts on them from when we bought the boat in '04 (don't know how long prior) and this was the first time I changed them. I only changed them because I had the alternators off and figured what the heck. There were new spare Daycos on board (from the PO) but they've been stored so long that they have twisted/set in such a way that I tossed them.

But maybe the Gates made back in the old days (2004) were better than those currently made in any number of 3rd world countries... ;)

[yachtsmanbill]

Ho Hummm...


http://www.beltfrog.com/catalog/9/Belting/52/V-Belts