Educate me on V-belts please

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sirrus
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Educate me on V-belts please

Post by sirrus »

Recently my alternator/AC belts started squealing (started the engine with rather discharged battery after a lot of cranking), which led me to thinking that I may need to get a new set of belts. Aside from squealing (that went away after I charged battery with AC charger at home), I thought that having spare belts wouldn't hurt. And that's where I have a problem - finding right belts :)

So I checked parts book and found those P/N:
  • J3227692 - power steering belt
  • J3227691 (56, 78 or 94 amp) - alternator/AC belt
  • J5362180 (85 amp) - another alternator/AC belt
  • J3228287 - air pump belt

First question is how do I know which alternator do I have? Should it be stamped somewhere on it or it can be determined from year? Alternator looks stock . Another thing is that in QTY column parts book says 1 belt is required and I have double belt driving alt and AC, but that is probably a typo or something.

Googling for parts using part numbers doesn't yield a lot of results and the ones I found are mostly noname belts. I'd prefer to buy quality ones (heard good things about Gates and Continental) - but I can't find any cross reference between Jeep part numbers and belt dimensions. What are the proper belts sizes for my rig? And what brands should I be looking at? I don't mind spending a little extra for quality, but within reason :)
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will e
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Re: Educate me on V-belts please

Post by will e »

Greetings. Here is a write up I did on the alternator belts.

viewtopic.php?f=7&t=9576&p=106151

I will go find the original pictures and upload there here (and edit the original post).
81 Waggy 'WILL E' Retired
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Re: Educate me on V-belts please

Post by sirrus »

Great information, thanks! So 15510 is the right one for alt/AC. What about other two belts?
I forgot to check rockauto, maybe it will suggest something too

What about brands? Dayco, duralast, bando, continental, acdelco, gates? Or doesn't matter?
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will e
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Re: Educate me on V-belts please

Post by will e »

Some notes I have on the power steering belt:

PS belt 15515 effective length 51.5 (too short) couldn't get on even with the distributor turned and the cap removed.
PS belt 15530 effective length 53 (too long)
PS belt 15520 effective length 52 - Still too short. If you removed the cap and turned the distributor you could probably get it on
PS belt 15525 effective length 52.5 worked. A little tight to get on but pulled nice.
PS belt Power steering belt. Tried several (see above) 15525 works like a charm. It's a bit difficult to get on but not impossible.
PS bolts 16mm deep socket and 17mm short socket
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
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tgreese
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Re: Educate me on V-belts please

Post by tgreese »

Interesting all this discussion. When I bought my J20, I routinely replaced all the belts and hoses. I recall I just ordered from the list on RockAuto, and everything fit fine.

I'm biased toward Gates and Dayco, but Conti or Delco should be fine too. Gates is the iconic brand, and Dayco is a close second. Product is likely not much different between the brands, but I'd trust their listings more. Duralast will be someone else's product relabeled, possible for the other brands too.
Last edited by tgreese on Fri Jul 10, 2020 11:11 am, edited 2 times in total.
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Re: Educate me on V-belts please

Post by sirrus »

That’s what I’d normally do, but there are a lot of options on rockauto with slightly different length, so I wanted to get some advice before ordering.


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Re: Educate me on V-belts please

Post by tgreese »

Regarding the 85 amp alternator, my '80 book shows that only applies to Police service. Maybe changed by 1988. Most of these alternators are Delco 10SI type, and Mad Electrical says the highest factory output for these is 65 amps. To get 85 amps, likely you'd need to go to a 12SI type, which has more cooling to support the higher amps rating. See here - http://madelectrical.com/electricaltech/delcoremy.shtml I'd guess if it's a 10SI it's not the 85 amp option.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
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Re: Educate me on V-belts please

Post by tgreese »

Looking at my J20, they are all Dayco "Top Cog" type. The AC/Alt belts are Dayco 15505. No numbers visible on the others. Probably what RockAuto calls for in Dayco: 15540 and 15295.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

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Re: Educate me on V-belts please

Post by MReese Wagoneer »

one thing to remember on the ALT/AC
anytime you have a paired belt like that you need to by a "Matched Set"
they are/should be the exact same length so one belt is not loose and the other tight
I did not do this when I ordered mine from Rock Auto, they do not have that option and mine are two different lengths, a minor difference but noticeable
when I find a good source i will let you guys know
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Re: Educate me on V-belts please

Post by candymancan »

My 90 has a 94a alternator. I believe the later year ones came with 94s from factory.
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Re: Educate me on V-belts please

Post by sirrus »

Looking at the air vents on the back it looks like 12SI. 89 TSM says that they were either 56amp or 94amp (with heavy duty package), and I have aux tranny cooler and relay box for trailer, which makes me think I should have a 94 amp version. I remember reading somewhere that last years all included heavy duty/towing package that optional before.

Back to belts and squealing - found part numbers on the belts that I have now. Alt/ac belt is Napa premium xl 25-7508, air pump is 25-7295 and power steering is 25-7535. Squealing is back for few minutes after start and I noticed that alternator pulley gets very warm to touch.

I’ll start with new belts (probably glazed), maybe get a rebuild kit for alternator with new bearings. Can pulley itself get glazed?


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Re: Educate me on V-belts please

Post by tgreese »

The HD option for the alternator seems like a reasonable conclusion.

No, no glazing the pulleys. Traction of the twin belts on the alternator should be very high. I would say the twin belts were used to drive the AC compressor, not the alternator. The alternator is a convenient location for putting tension on the belts.

These modular alternators are easy to rebuild, but I wonder if it's worthwhile considering how cheap a reman is in exchange.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

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Re: Educate me on V-belts please

Post by sirrus »

Yes, from what I’ve seen rebuild is very easy, except maybe for removing/installing bearings. I’ve seen powermaster rebuild kits for about $40, haven’t checked reman alternators yet. I’m leaning towards rebuilding it myself just because it’s easy and I’ll know that I used quality parts - never sure about last one for rebuilt units.

There’s also an option of buying a new powermaster 140/80 alternator , but it’s $140ish and I’m not planning on installing any extra lights, winch or whatever. Stock 94amp should be enough.

Are any gotchas about removing/installing it? Wiring and 2 bolts and that’s it?


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Re: Educate me on V-belts please

Post by candymancan »

I just got mine from autozone. Been working fine for a few years now.


Ive had this issue with belts on the alternator before. I just showered after working on my frame for 9 hours today.. when I get some rest ill go look at the part number for the belts i got. I did extensive research on it and found the right belts to get.
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Re: Educate me on V-belts please

Post by GrandW »

Since the alternator is on the sliding bracket, it may just need to be tightened to stop the belt from squealing. From underneath you can fit a crowbar / screwdriver between the alternator and engine to get some light leverage, then while it's taunt, bolt it into place.
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Re: Educate me on V-belts please

Post by 67GMC »

MReese Wagoneer wrote: Fri Jul 10, 2020 7:22 pm one thing to remember on the ALT/AC
anytime you have a paired belt like that you need to by a "Matched Set"
they are/should be the exact same length so one belt is not loose and the other tight
I did not do this when I ordered mine from Rock Auto, they do not have that option and mine are two different lengths, a minor difference but noticeable
when I find a good source i will let you guys know
Agree with this. Just have this problem now. One Gates and One Dayco. Must be a slight difference in length that causes a little squeal on start up but not noticeable once its warmed up. Supplier didn't have 2 the same brand but had one of each brand and I didn't think it would make a difference. Not earth shattering by any means -just a little annoying.
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Re: Educate me on V-belts please

Post by MReese Wagoneer »

67GMC wrote: Sat Jul 18, 2020 7:43 pm

Agree with this. Just have this problem now. One Gates and One Dayco. Must be a slight difference in length that causes a little squeal on start up but not noticeable once its warmed up. Supplier didn't have 2 the same brand but had one of each brand and I didn't think it would make a difference. Not earth shattering by any means -just a little annoying.
I ordered 2 Gates from Rock Auto who did not spec Matched Set and they are different. :banghead:

they squeal , but it is lower priority lol I will be finding a Matched Set
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Re: Educate me on V-belts please

Post by sirrus »

I realized I never posted what I ended up with :) Hopefully that will help someone

So for alternator/AC belts I got NAPA 25-7535. When I asked about matched set, I got that deer-in-the-headlights look from the guy there and then he explained that they should be matching anyway due to higher tolerances they have now. Of course when I put those belts on, one more obviously tighter than the other, but squealing went away. After driving for about 200 miles I've retightened them and surprisingly they are even now. So they are matching, but after some breaking in :)

I also replaced air pump and PS belts (NAPA 15295 and 15535, respectively). After some research I've found that NAPA brand belts are actually made by Gates, and they have 2 lines - cheaper ones (PN starts with 15, like the ones I got for air and PS) and premium (PN starts with 25, like the AC/alt belt). Premium ones are $20ish and cheap ones are just $5-6. New PS belt definitely helped as I was suspecting the old one was slipping occasionally, and air pump belt I replaced just because I already did all the other ones :)
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Re: Educate me on V-belts please

Post by Wookiee »

Has anyone come up with an alt belt number bypassing the a/c compressor?
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tgreese
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Re: Educate me on V-belts please

Post by tgreese »

If you bypass, you need a belt path that clears all the brackets and such, and you need some way to tension the belts. From there, I suggest you use a rope or string and wrap it around the pulleys with the adjuster at mid-range. Measure the string and ask for belts of that length at your local parts store. If you are friendly with the store, they should let you try that length and see if it will work. If not, go up or down in length until you find one that will work.

The length of the belt is typically part of the part number. For example, your 25-7535 may be 25 or 35 inches overall length. Some snooping in the listings should reveal the number's meaning. Then you can try ordering your candidate belts online, if you want to go that route.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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