1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Are O'Reilly Masterpro V belts any good?

Discussion in '6.9L IH & 7.3L IDI Diesels' started by Cubey, Dec 5, 2019.

  1. gandalf

    gandalf Senior Member

    Posts:
    3,337
    Likes Received:
    523
    Joined:
    Jan 21, 2005
    Location:
    CA
    I didn't catch that. All I can say, then, is that 3 of the 4 belts on my truck are Fleetrunner, and have been for the past 2 years. They've given me no problem, survived a trip to Canada and back, ~2100 miles, plus, of course, shorter local area driving.
     
    Last edited: Dec 7, 2019
    Cubey likes this.
  2. Cubey

    Cubey Full timer RVer

    Posts:
    1,442
    Likes Received:
    339
    Joined:
    Oct 18, 2017
    Location:
    USA
    I will probably put the Fleetrunner belt on the alternator since it's the furthest back and takes the most abuse from flapping. The $3 Gates XL can't be beat for the PS. It has the probably original belts on PS and AC. The current PS belt is this JC-577.

    20191207_113056.jpg

    It's cracked to hell on the underside but I had nothing to replace it with at the truck stop.

    The AC belt might be a bit newer since the RV had a spare Motorcraft for it. It looks less worn than the one on it to be honest. It could be it got new Motorcraft belts in the early to mid 90s but that's 25+ years ago now.

    Once I get all the new belts, the Fleetrunner will go on the ALT, and the XLs will go on PS and AC. I will have lots of spares then.
     
  3. Garbage_Mechan

    Garbage_Mechan Garbage Mechanic

    Posts:
    804
    Likes Received:
    352
    Joined:
    Jun 9, 2008
    Location:
    Central Cal Foothills
    That spec change on the Alt belt was what the Gates rep told me years ago. That one belt they changed the specs to make it live better. Back when I had a fleet of these it did make a difference.
     
    Cubey likes this.
  4. Garbage_Mechan

    Garbage_Mechan Garbage Mechanic

    Posts:
    804
    Likes Received:
    352
    Joined:
    Jun 9, 2008
    Location:
    Central Cal Foothills
    On the subject of the alternator belt, some folks just run a belt around water pump and alternator. Do we need 3 belts to power the fan? Anyone know the part # for the belt to try this? It seems like getting rid of the Alt. flapping might be worth the increased load on the ps and ac belts since they seem to last 2x the Alt.
     
    riphip likes this.
  5. Cubey

    Cubey Full timer RVer

    Posts:
    1,442
    Likes Received:
    339
    Joined:
    Oct 18, 2017
    Location:
    USA
    You have to run the fan off of PS and AC belts basically, unless you purposely try to bypass it, coming straight off the crank somehow but why would you? Do you really want to skimp on the WP's power source?

    You can get by removing the AC belt and I might do that since my AC has no pressure right now, and my blower probably needs replacement because the fuse blows randomly for some reason. But then again, it's a good redundancy to have more belts turning the WP in case you lose one, or even two.

    When my alt belt went, but before I knew it had, my coolant was running at 200-210. Normally it's 180-190. The two remaining belts are so old and rotten, they probably slip and don't power the WP as well as they should. I was watching my temp gauge like a hawk because I knew something was up, I just didn't know what. I chocked it up to it being 70 degrees, windy and lots of steep hills, some with truck lanes. (A normally 2 lane highway). Then I found no power brakes, and my immediate thought was the vac pump and went to the truck stop straight down the highway I knew about. In retrospect, it makes sense. The best belt was lost and the crappy ones, despite there being 2, probably couldn't keep up as well by themselves.
     
  6. Cubey

    Cubey Full timer RVer

    Posts:
    1,442
    Likes Received:
    339
    Joined:
    Oct 18, 2017
    Location:
    USA
    Well good, since the Fleetrunner will be used for ALT and XLs for PS and AC. I'm not shy about putting a lot of tension on the belts. I'm not heavy and it's hard to get a good angle on the accessories in the van chassis, so I know darn well I'm not putting too much. I did see the 1/2" socket wrench holes for the PS and AC, I had to use a 3/8" socket wrench with a 1/2" adapter because it's so cramped, especally the PS. There was no way I could fit my big breaker bar in there. I never noticed that the VP bracket has a 3/8" square hole too, or maybe that's only on vans? Anyway, I used that too. AC is the hard one, I couldn't find my big tire iron and I didnt feel like digging everything out, so i used the 18" handle of my 1/2" breaker bar, that worked well enough. I saw no excessive flap when I cranked it up after getting all the belts put back.
     
  7. Garbage_Mechan

    Garbage_Mechan Garbage Mechanic

    Posts:
    804
    Likes Received:
    352
    Joined:
    Jun 9, 2008
    Location:
    Central Cal Foothills
    AC has a half inch hole on all the F series I’ve seen anyway....
     
    Cubey likes this.
  8. jaluhn83

    jaluhn83 Full Access Member

    Posts:
    1,573
    Likes Received:
    33
    Joined:
    May 19, 2012
    Location:
    Seabeck WA
    IMHO, pretty much all the off brand cheap parts store stuff is emergency use only, i.e. masterpro belts. Go to rock auto and get better stuff for far cheaper. I've had no significant issues with any of the name brand belts off there.

    36 vs 38* belt probably doesn't matter - that small of the angle change is well within the amount I'd expect the belt to give and wear/production variation will likely cause and even greater variation anyway. 2* is about 0.012" change in the belt width on one side.
     
    Cubey likes this.
  9. wyatt tatman

    wyatt tatman Registered User

    Posts:
    4
    Likes Received:
    2
    Joined:
    Sep 25, 2018
    Location:
    Montana
    As a former employee of OReilly auto parts, my personal opinion NO they are garbage. Go with either the Gates xl or the fleetrunner belts warranty is better and 50/50 chance of it being made in the USA.
     
    Cubey likes this.
  10. Cubey

    Cubey Full timer RVer

    Posts:
    1,442
    Likes Received:
    339
    Joined:
    Oct 18, 2017
    Location:
    USA
    The new VP bulb I got from an O'Reilly way back in February or so looks like the cardboard sleeve was made in the 90s. Ever even heard of "Armor Mark"? I think that's what they had in stock for MasterPro. I questioned it before I paid but they said that's what they had and the package shows it fits Gates 7330. It fits fine, better than the wrong too narrow Napa XL belt it had when I got it.

    WIN_20191209_10_02_48_Pro.jpg
     
  11. raydav

    raydav Full Access Member

    Posts:
    336
    Likes Received:
    117
    Joined:
    Sep 12, 2006
    Location:
    Apple Valley, CA
    I have six vehicles that run and run Masterpro in all of them; except the twelve foot serpentine in my 2001 PSD.

    The real number for the 9580 is 17580 or 58017. It is 17/32 wide and 58.0 long. But I find the industry is getting a bit sloppy with the width dimensions.

    17580
    17-580
    9580
    25-9580
    Napa NBH 259580
     
  12. riphip

    riphip Supporting Member Supporting Member

    Posts:
    642
    Likes Received:
    172
    Joined:
    Nov 16, 2005
    Location:
    Memphis, TN.
    Mine is a 1986 6.9 but I think the belts are the same. I use the DAYCO GOLD TOP COG belts from Rockauto.com

    A/C: 17630......A/C to WP & Crank (13A1600)
    VP: 15325......VP to ALT (11A0825)
    PS: 17600......PS to WP & Crank (13A1525)
    ALT: 17425......Short belt from ALT to WP only (13A1080)...Eliminates vibration that long belt develops (not a Gold)

    These are not the Economy belts but are the stronger longer-lasting belts. Rockauto always has great pricing on these.
     
    dgr likes this.
  13. Trevtron

    Trevtron Supporting Member Supporting Member

    Age:
    43
    Posts:
    245
    Likes Received:
    118
    Joined:
    Aug 18, 2016
    Location:
    Katy, Texas
    Go Gates
     
  14. dgr

    dgr Full Access Member

    Posts:
    832
    Likes Received:
    193
    Joined:
    Aug 5, 2012
    Location:
    sac town
    @riphip thanks for the list. I was wondering what size to use for water pump to alternator. It seems to me that if the diesel pulse is an issue with the belts that moving the belt off the crank may give it a little more life.
     
  15. Fixnstuff

    Fixnstuff Full Access Member

    Posts:
    150
    Likes Received:
    36
    Joined:
    Sep 28, 2015
    Location:
    Kitsap County, Washington
    I may be able to help you understand that variance in the specification. I replaced my alternator belt back in 2015 with a special Gates high performance green stripe(?) belt which was hard to find anywhere thereafter. It may have been the precursor to the Fleetrunner belt. (By the way, the Gates website has extensive documents and specifications for their numerous belts).

    The belt that I used was oversized, much as you describe for the Fleetrunner. It is purposely designed that way so that: When first installed it rides high in the pulley V, appears to be a little too wide as well, BUT after running it for awhile (not very long, like maybe hours or a few days or a it longer depending upon how much you drive) it seats down into the pulley for a very good grip and fit. That is what it is supposed to do and that's why it's designed that way. I found that info at the Gates website, in a belts specifications PDF.
    I can't look for the package it came in tonight but I DO HAVE IT in a box with spare belts and I can find it tomorrow in the daytime and post here which belt it is.

    Also I found that this Gates belt flopped around a bit less than the previous belt that was on it. It also straightens out as soon as the RPM goes up. Most belts should do that and it's probably not possible or necessary to get rid of that flapping on that very long upper span of the alternator V belt.

    I swapped out the belts and other components that didn't really need to be changed yet because I just want all new and dependable parts under the hood and elsewhere. I want to get all of that done while it is convenient to do before I take this truck on a long haul, towing a trailer over some mountain ranges etc. and I DON'T want to be stuck on the side of the road in a remote area (or anywhere) with a full bed and full trailer loaded with valuable possessions due to some replaceable part that failed.

    Lastly, I bought some of those 'close-out' low priced belts from Rock Auto Parts for temporary spare belts because I couldn't afford to buy expensive spare belts at the time. I want to mention that some of these 'close out' belts could be quite old, or they could be fairly new. If they are quite old, they probably won't last as long as a newer belt would, simply due to ageing of the rubber. That's why I am considering them as temporary low cost replacements.

    Gates and probably some other big name rubber companies also make OEM labelled belts for auto manufacturers. I'm quite sure that I read somewhere that Motorcraft belts were/are made by Gates Rubber Co.
    That should come as no surprise if you know much about Gates Rubber Company and their excellent long history in the research, design and development of rubber belts. I also believe that other big name rubber companies can make very good belts but have several reasons for selecting Gates as my top choice but I don't have the time or convenience to explain why.
     
    Last edited: Dec 11, 2019

Share This Page