V Belts replacement

[Andrew Fort]

I can’t seem to find a good write up or anything on replacing the 4 v belts on my truck. It’s a 1990 F350 with A/C. I know the alt can adjust up and down, but I didn’t see any adjustments on anything else. Any help is appreciated.


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[Golden Helmet]

It's pretty easy to do. The vacuum pump you don't have to do anything with, its belt will come off when you loosen the alternator bolts. The power steering pump and alternator each have one bolt that serves as a hinge and a second that lets you adjust the tension. I forget if the AC has 2 or 3 bolts you have to loosen to adjust it, but it's the same idea. Outermost belt comes off first, so the order of removal is AC -> power steering pump -> vacuum pump -> alternator. And if it's not obvious, just loosen the bolts, don't pull them out.

Installation is the reverse of removal. A 2-3 foot pry bar on the alternator will help you tension the belt, and I use the pry bar for the AC compressor too. For the power steering pump, there's a square hole that you can stick a 1/2' breaker bar perfectly in to to make tightening that belt super easy. The alternator belt is the biggest PITA of the bunch, if you find an easy way to do that one let me know

Definitely pay attention to your alternator belt. It wobbles like crazy no matter what you do and it breaks far more often than the other belts. When it snaps, your vacuum pump belt stops being spun and you lose your power brakes. Keep spare belts and underpants handy.

 

[riphip]

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.

 

[whiteboyslo]

I can never remember exactly which bolts do which, but as been mentioned, pretty much everything has a pivot bolt and a adjustment/tension bolt. Loosen both/all, then start cranking.

Mike

 

[snicklas]

Check out this thread:

https://www.oilburners.net/threads/tools-needed.82004/

My 88 lost the belts on the way to work. I have what tools you need and the adjustment info.....

 

[IDIBRONCO]

The vacuum pump you don't have to do anything with,

You should loosen the vacuum pump too. The lengths of the new belts could be different enough that you won't be able to tighten one or the other enough without doing this.

I forget if the AC has 2 or 3 bolts you have to loosen to adjust it,

It's actually four bolts. Two long bolts and one short bolt on the front. One short bolt on the back. It's kind of hidden and will make you cuss if you don't know that it's there.

 

[gfemling]

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

ALT: 17425......Short belt from ALT to WP only (13A1080)...Eliminates vibration that long belt develops (not a Gold).

Interesting observation- my ‘87 6.9 standard V-belt confit uses 17580 for alt drive and goes around both crank and water pump pulleys (and yes flaps around significantly at idle especially if not adequately tensioned); appears this belt changes config to eliminate including crank pulley- powers alt from water pump only. Curious if this a standard mod that I was just uninformed about before now??

 

[renjaminfrankln]

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.

Thanks, my alternator belt is the "long route" and wobbles like crazy, even though it is new, tight and the belt pully alignment seems good.

Need to get one of those short belts.

 

[riphip]

you'll be glad you did the change.

 

[chris142]

Fwiw I had no luck with gates belts. They squealed from the get go even when real tight.I got the Duralast ones from AutoZone. Made in usa. Don't know who actually makes them but they have been flawless. Someone mentioned may be made by Continental. My shop cost is $4 ea too!

 

[austin92]

Is that short wp to alt belt from a different application that happens to fit or is this like some factory fix for frequently broken belts? I’ve put about 35k miles on these duralast belts, I have the long one that includes the crank. It wobbles but it’s never broke. I understand why people are swapping to the short belt in hopes of keeping power brakes but the long one is insurance to keep the wp spinning if ps belt breaks. With the short belt and broken ps belt, you’d lose everything, right? I will probably keep the wobbling crank belt on the truck but a straight wp to alt belt as a spare behind the seat just to get me home. What would be really cool though is a triple alt pulley, my ac has been deleted so I could run 2 to the alt as insurance to never lose vacuum


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[chris142]

I have never had a belt break or come off. I'm running the stock belt setup.

 

[The_Josh_Bear]

Is that short wp to alt belt from a different application that happens to fit or is this like some factory fix for frequently broken belts? I’ve put about 35k miles on these duralast belts, I have the long one that includes the crank. It wobbles but it’s never broke. I understand why people are swapping to the short belt in hopes of keeping power brakes but the long one is insurance to keep the wp spinning if ps belt breaks. With the short belt and broken ps belt, you’d lose everything, right? I will probably keep the wobbling crank belt on the truck but a straight wp to alt belt as a spare behind the seat just to get me home. What would be really cool though is a triple alt pulley, my ac has been deleted so I could run 2 to the alt as insurance to never lose vacuum


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That's a good call on losing the booster if that belt breaks. I still have the long belt but years ago found an idler pulley off a mid-90's maxima that fits good enough on the lower alternator bracket bolt that keeps the long side of the triangle under just a hair of tension. No breaks since, got the same belt going 5-6 years now.

I had a bad time with that(NAPA) belt before this mod. Broke 3 in one year. Switched to gatorback belts and still have that first one, FWIW.

 

[riphip]

I understand why people are swapping to the short belt in hopes of keeping power brakes but the long one is insurance to keep the wp spinning if ps belt breaks. With the short belt and broken ps belt, you’d lose everything, right? I will probably keep the wobbling crank belt on the truck but a straight wp to alt belt as a spare behind the seat just to get me home. What would be really cool though is a triple alt pulley, my ac has been deleted so I could run 2 to the alt as insurance to never lose vacuum

When long ALT belt goes, it throws all the belts, except VP. Best insurance is to carry extra belts, no matter the brand. Short belt is best for me. If PS belt goes, you know it immediately.
Been running this truck for 25 years.

 

[Cubey]

For alternator belt, I carefully use a long ass tire iron (an old HFT one) wedged in to the drivers side and pull it towards the passenger side while it is braced against the alternator casing. I did that a year ago after replacing the alternator and it hasn't thrown the belt. I recently redid it as the belt seemed a little loose. It's probably a bad way to do it but it seems to work for me. I don't go insane on pulling the tire iron though.

I've had the truck almost two years (will be two in February) with the belts it still has so I guess I'm lucky or my method is good.