CUTLASS AC belt issues

Tz44

Tz44

Not-quite-so-new-guy
Mar 24, 2012
43
8
Bought a 1986 cutlass supreme this weekend and I’m trying to sort out an issue I’ve found with the AC belt. It appears to be loose because it flaps around from the crank pulley to the bottom of the compressor.
I tried adding tension to it using a breaker bar in the 1/2” drive slot at the top of the Ac compressor bracket but it’s still flopping around a lot.
It’s still got the original 307 and v belts are new to me so I’m very inexperienced with them. I’m assuming the curved slot at the top of the bracket is where I would adjust tension? It’s fluttering a lot and I’m thinking there’s something I’m missing. Can anyone tell me other things I should check or a different way to add tension?
Thanks in advance
 
TURNA

TURNA

Geezer
Jul 24, 2009
8,688
113
Socialist NY
That just how Oldsmobile's are
 
69hurstolds

69hurstolds

Comic Book Super Hero
Jan 2, 2006
2,611
113
Helpful... thank you...
Long story. I made a vow to not engage until someone has had 25 posts. Even though you've been here a while.

If you're used to serpentine belts, you don't see much deflection. When working with V-belts on a G-body Olds V8 A/C, you're going to see plenty of deflection on the bottom. That is why your bottom radiator hose clamp has a shield on it to keep that stupid belt from cutting into the hose.

Anyway, tried to follow what you did, but maybe this drawing will help. I'm assuming you have the correct length belt on it. (7/16" x 52") GM p/n 9433756. You'll need to loosen bolts 16, 7, and 3. You can usually put a 1/2" breaker bar in the square hole on part #2. Leverage to correct tightness, (if you have a deflection belt gage, great) and then tighten #16. No nut to worry about because it screws into #2. Tighten it enough to ensure it doesn't move. When happy with the tension, tighten up 3 and 7 bolt (with nut). Kinda PITA, but that's how I do it. I have a belt deflection gage. Forgot what the tension should be, but either way, regardless of how tight you make that sucker, it will deflect some. It's very long and it's just the nature of the beast.

Early 307 A-C bracket illustration.jpg
 
Tz44

Tz44

Not-quite-so-new-guy
Mar 24, 2012
43
8
Long story. I made a vow to not engage until someone has had 25 posts. Even though you've been here a while.

If you're used to serpentine belts, you don't see much deflection. When working with V-belts on a G-body Olds V8 A/C, you're going to see plenty of deflection on the bottom. That is why your bottom radiator hose clamp has a shield on it to keep that stupid belt from cutting into the hose.

Anyway, tried to follow what you did, but maybe this drawing will help. I'm assuming you have the correct length belt on it. (7/16" x 52") GM p/n 9433756. You'll need to loosen bolts 16, 7, and 3. You can usually put a 1/2" breaker bar in the square hole on part #2. Leverage to correct tightness, (if you have a deflection belt gage, great) and then tighten #16. No nut to worry about because it screws into #2. Tighten it enough to ensure it doesn't move. When happy with the tension, tighten up 3 and 7 bolt (with nut). Kinda PITA, but that's how I do it. I have a belt deflection gage. Forgot what the tension should be, but either way, regardless of how tight you make that sucker, it will deflect some. It's very long and it's just the nature of the beast.

View attachment 121462
You’ve made my day. This helps ease my mind a lot. I’d post more but don’t want to be a burden and try to do as much research as I can myself without asking too many dumb questions. Thank you for your response, it wasn’t in vain lol
 
69hurstolds

69hurstolds

Comic Book Super Hero
Jan 2, 2006
2,611
113
NP. Don't hold back. No wallflowers here. Post up your wins and post up any questions about how to get a win. A lot of snark sometimes because that's how it's done in garages for the most part, but you're still likely to find an answer to your questions through all this BS. There's a whole lot of experience in this forum just waiting to be tapped.
 
Tz44

Tz44

Not-quite-so-new-guy
Mar 24, 2012
43
8
Long story. I made a vow to not engage until someone has had 25 posts. Even though you've been here a while.

If you're used to serpentine belts, you don't see much deflection. When working with V-belts on a G-body Olds V8 A/C, you're going to see plenty of deflection on the bottom. That is why your bottom radiator hose clamp has a shield on it to keep that stupid belt from cutting into the hose.

Anyway, tried to follow what you did, but maybe this drawing will help. I'm assuming you have the correct length belt on it. (7/16" x 52") GM p/n 9433756. You'll need to loosen bolts 16, 7, and 3. You can usually put a 1/2" breaker bar in the square hole on part #2. Leverage to correct tightness, (if you have a deflection belt gage, great) and then tighten #16. No nut to worry about because it screws into #2. Tighten it enough to ensure it doesn't move. When happy with the tension, tighten up 3 and 7 bolt (with nut). Kinda PITA, but that's how I do it. I have a belt deflection gage. Forgot what the tension should be, but either way, regardless of how tight you make that sucker, it will deflect some. It's very long and it's just the nature of the beast.

View attachment 121462
I followed that procedure when tightening but noticed I could see some marks on the lower radiator hose guard from the belt and thought for sure there was a problem. My other g body has a 5.3 but I wanted a car that was more original and finally found one that hadn’t been messed with. The olds 307 obviously has some flaws I just wasn’t aware of. You’re right about 3 and 7 being a PITA but I managed to get them tight with a ratchet and an open ended wrench. Thanks to you I’ll be driving it to work tomorrow instead of leaving it sitting.
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,053
113
Melville,Saskatchewan
Olds belt system is a PITA. Many spacers and multiple tightening spots that are hard to get at. I leave to slightly loose on the power steering, so I can use a 15mm or 9/16 wrench at the top depending on which car to tighten it. I have also had issues with new belts stretching excessively needing retightening, like 4 times.
 
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