Why is my ac/heat ductwork so dang sloppy? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Tumbleweed1C4 · 03-12-2016, 10:04 AM

I repaired my flapper, bought and installed a vac canister, installed all new ductwork, and a new s-duct, and almost finished putting everything all together (with a new refurbished tach cluster

).
But I am not sure if I am missing something because the s-duct to floor vent/defrost box connection is looser than a goose. In fact, the whole thing is sloppy. The flapper box connection to the firewall box is screwed together, but not confidence inspiring tight. The s-duct is screwed on there, and then the floor/defrost box, and I feel as if I am relying on the bolt that goes through the firewall to hold the floor/defrost box to hold everything together, and it does a very poor job of it. I am starting to understand why the PO had a load of duct tape around everything. Not what I was hoping for. Here is a picture of the s-duct connection and everything together. It looks like it doesn't go in far enough to screw together as I can see the holes in the metal of the floor vent box and it is bottomed out. I flipped the s-duct around to make sure I had it on the right way and this ended up like it made more sense, but I could be wrong. What am I missing?
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Name: 20160310_193742.jpg
Views: 236
Size: 34.1 KB

Davidf · 03-12-2016, 10:10 AM

The diverted box is supposed to be screwed to the S-duct.

hdff · 03-12-2016, 12:08 PM

Quote:

Originally Posted by Davidf

The diverted box is supposed to be screwed to the S-duct.

Looks to me like it is

hdff · 03-12-2016, 01:13 PM

Quote:

Originally Posted by Davidf

The diverted box is supposed to be screwed to the S-duct.

Looks to me like it is

F.A.A.benny · 03-12-2016, 01:35 PM

the s-duct should be screwed to the metal duct as well

El Dorado Jim · 03-12-2016, 01:39 PM

I will take a look at mine and see if I can see any differences

Tumbleweed1C4 · 03-12-2016, 02:00 PM

I took it all apart and redoing it. I drilled new holes for s duct to metal housing, then discovered the top and bottom clear but screws front and back interfere with movement of defrost flapper. Put some of that double sided foam tape around metal duct to make a tighter fit. Will do same on firewall side and see if I can secure that joint better too.

Andy4639 · 03-12-2016, 03:59 PM

It's been a long time since I did mine but I'm thinking I redrilled the floor vent bolt hole and moved it closer to the passenger side of the truck.

Tumbleweed1C4 · 03-12-2016, 04:15 PM

I thought about that too Andy., but I think I got it pretty good now. Combination of several things. Put the foam tape to secure the s duct connections better, added a couple screws all the way around, and holes in heater core box were all wopped out. Put bigger screws in there, and everything came together pretty good. Installing new tach now and led dash lights and hopefully get her started and test heater/tach/led lighting today yet.

100%Chevy · 03-12-2016, 04:28 PM

Did you get the "S" duct from LMC?
If so,how does it fit?
And,did you buy new duct hose too?Is so,how well does it work?
I need to get these and wanting some comments on the quality before I buy if you don't mind.
Thanks,Mike.

Andy4639 · 03-12-2016, 08:25 PM

Glad you got it figured out.
I like the feeling!

03-12-2016, 10:04 AM	#1
Tumbleweed1C4 Registered User Join Date: Jan 2014 Location: Gaylord, Michigan Posts: 127	Why is my ac/heat ductwork so dang sloppy? I repaired my flapper, bought and installed a vac canister, installed all new ductwork, and a new s-duct, and almost finished putting everything all together (with a new refurbished tach cluster ). But I am not sure if I am missing something because the s-duct to floor vent/defrost box connection is looser than a goose. In fact, the whole thing is sloppy. The flapper box connection to the firewall box is screwed together, but not confidence inspiring tight. The s-duct is screwed on there, and then the floor/defrost box, and I feel as if I am relying on the bolt that goes through the firewall to hold the floor/defrost box to hold everything together, and it does a very poor job of it. I am starting to understand why the PO had a load of duct tape around everything. Not what I was hoping for. Here is a picture of the s-duct connection and everything together. It looks like it doesn't go in far enough to screw together as I can see the holes in the metal of the floor vent box and it is bottomed out. I flipped the s-duct around to make sure I had it on the right way and this ended up like it made more sense, but I could be wrong. What am I missing? __________________ Sleep safe in your beds because rough men stand ready in the night to visit violence on those who would do you harm 72 K5 Blazer 72 K10 SWB (in pieces under slow construction!) 72 K20

03-12-2016, 10:10 AM	#2
Davidf Registered User Join Date: Nov 2014 Location: Austin Posts: 749	Re: Why is my ac/heat ductwork so dang sloppy? The diverted box is supposed to be screwed to the S-duct.

03-12-2016, 01:35 PM	#5
F.A.A.benny Registered User Join Date: Jul 2015 Location: Euless, Tx Posts: 431	Re: Why is my ac/heat ductwork so dang sloppy? the s-duct should be screwed to the metal duct as well

03-12-2016, 01:39 PM	#6
El Dorado Jim Registered User Join Date: Dec 2009 Location: El Dorado Ca Posts: 3,374	Re: Why is my ac/heat ductwork so dang sloppy? I will take a look at mine and see if I can see any differences

03-12-2016, 02:00 PM	#7
Tumbleweed1C4 Registered User Join Date: Jan 2014 Location: Gaylord, Michigan Posts: 127	Re: Why is my ac/heat ductwork so dang sloppy? I took it all apart and redoing it. I drilled new holes for s duct to metal housing, then discovered the top and bottom clear but screws front and back interfere with movement of defrost flapper. Put some of that double sided foam tape around metal duct to make a tighter fit. Will do same on firewall side and see if I can secure that joint better too. __________________ Sleep safe in your beds because rough men stand ready in the night to visit violence on those who would do you harm 72 K5 Blazer 72 K10 SWB (in pieces under slow construction!) 72 K20

03-12-2016, 03:59 PM	#8
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Why is my ac/heat ductwork so dang sloppy? It's been a long time since I did mine but I'm thinking I redrilled the floor vent bolt hole and moved it closer to the passenger side of the truck. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

03-12-2016, 04:15 PM	#9
Tumbleweed1C4 Registered User Join Date: Jan 2014 Location: Gaylord, Michigan Posts: 127	Re: Why is my ac/heat ductwork so dang sloppy? I thought about that too Andy., but I think I got it pretty good now. Combination of several things. Put the foam tape to secure the s duct connections better, added a couple screws all the way around, and holes in heater core box were all wopped out. Put bigger screws in there, and everything came together pretty good. Installing new tach now and led dash lights and hopefully get her started and test heater/tach/led lighting today yet. __________________ Sleep safe in your beds because rough men stand ready in the night to visit violence on those who would do you harm 72 K5 Blazer 72 K10 SWB (in pieces under slow construction!) 72 K20

03-12-2016, 04:28 PM	#10
100%Chevy Registered User Join Date: Jun 2008 Location: Moss Point,Ms. Posts: 1,439	Re: Why is my ac/heat ductwork so dang sloppy? Did you get the "S" duct from LMC? If so,how does it fit? And,did you buy new duct hose too?Is so,how well does it work? I need to get these and wanting some comments on the quality before I buy if you don't mind. Thanks,Mike.

03-12-2016, 08:25 PM	#11
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: Why is my ac/heat ductwork so dang sloppy? Glad you got it figured out. I like the feeling! Attached Images __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.



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