Air bags and trailing arms?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72kool · 10-14-2015, 12:51 AM

This may be better in the suspension forum, if so I apologize. I have a '72 C20 gmc with rear trailing arms and coil sorings. I am replacing the trailing arm and need new springs. I am thinking about bags instead. I tow a lot with this truck so first, is this a good idea? I don't see why it wouldn't be. Better ride qualty, adustable load stability.. Am I wrong? My second question is, what/where? I read a thread on the install but unsure where to buy them from. I want a kit that will hold up to the extra weight from towing and be suitable for a smooth ride.

**special-K** · 10-14-2015, 07:29 AM

That'll work. I am considering this for my shortbed that has 4/6 drop. I don't want to ruin the frame by hacking out a c-notch, but want to be able to still use the truck and tow. Also, I can give the truck rake when I want to or go level like the 4/6 drop.

**slomotion** · 10-14-2015, 08:09 AM

I put a set of Air-Ride bags under my C20 years ago. The trailing arms are the ideal set up for these because they center the third member. I had to fabricate a set of top hats (spacers) because of the distance from the diff. to the frame, but I've not had any problems with the system at all. There are three things that need to be kept in mind though; You have to be aware of your ride height particularly at night because they will effect your headlight aiming. They soften the ride, but as a result of that the rear end isn't as stiff and without an anti-sway bar the truck will lean on some turns. The bags are particularly susceptible to any cuts or sparks.
I piped mine in series. This was because I have overload springs and in the case of a catastrophic failure both bags would deflate and the rear would settle on the overloads at least allowing me to get off the highway.
As far as installation is concerned, you're best bet is to follow the manufacturer's instructions for your system. That way any warranties wouldn't be voided.

midniteblues · 10-14-2015, 08:23 AM

you could allways add the helper bags inside the springs.
then there is air shocks if you wanna deal with them.

bags are great but like said above you should have some sorta fail safe way too keep rolling if there is a problem.

**Tom Vogel** · 10-14-2015, 09:03 AM

Early Classic Enterprises has the perfect setup. Works awesome.

72kool · 10-14-2015, 09:31 AM

slomotion, do you have pictures and more info on what bags you have? im wanting to use the style i can bolt right where the springs are. i have thought about using a rear sway bar anyways so that wont be an issue. i also have the rear overload springs so that is there as well. i want to run the air lines to fill ports in the bumper and adjust them my self. dont need the compressor or anything. just want to have a smooth ride and load support when needed

72kool · 10-14-2015, 03:06 PM

Also would i need to get a special trac-bar or anything ? im not wanting to lower this extremely but if i wanted to run it lower to just level it, would that be an issue with everything else stock? sorry for dumb questions but im new to the air bags and lowering. usually do lifts and have only installed the load helper bags on new trucks

10-14-2015, 12:51 AM	#1
72kool Registered User Join Date: Dec 2012 Location: kearney nebraska Posts: 613	Air bags and trailing arms?? This may be better in the suspension forum, if so I apologize. I have a '72 C20 gmc with rear trailing arms and coil sorings. I am replacing the trailing arm and need new springs. I am thinking about bags instead. I tow a lot with this truck so first, is this a good idea? I don't see why it wouldn't be. Better ride qualty, adustable load stability.. Am I wrong? My second question is, what/where? I read a thread on the install but unsure where to buy them from. I want a kit that will hold up to the extra weight from towing and be suitable for a smooth ride.

10-14-2015, 07:29 AM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,859	Re: Air bags and trailing arms?? That'll work. I am considering this for my shortbed that has 4/6 drop. I don't want to ruin the frame by hacking out a c-notch, but want to be able to still use the truck and tow. Also, I can give the truck rake when I want to or go level like the 4/6 drop. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

10-14-2015, 08:09 AM	#3
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,821	Re: Air bags and trailing arms?? I put a set of Air-Ride bags under my C20 years ago. The trailing arms are the ideal set up for these because they center the third member. I had to fabricate a set of top hats (spacers) because of the distance from the diff. to the frame, but I've not had any problems with the system at all. There are three things that need to be kept in mind though; You have to be aware of your ride height particularly at night because they will effect your headlight aiming. They soften the ride, but as a result of that the rear end isn't as stiff and without an anti-sway bar the truck will lean on some turns. The bags are particularly susceptible to any cuts or sparks. I piped mine in series. This was because I have overload springs and in the case of a catastrophic failure both bags would deflate and the rear would settle on the overloads at least allowing me to get off the highway. As far as installation is concerned, you're best bet is to follow the manufacturer's instructions for your system. That way any warranties wouldn't be voided. __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

10-14-2015, 08:23 AM	#4
midniteblues Registered User Join Date: Jul 2011 Location: strausstown pa Posts: 3,394	Re: Air bags and trailing arms?? you could allways add the helper bags inside the springs. then there is air shocks if you wanna deal with them. bags are great but like said above you should have some sorta fail safe way too keep rolling if there is a problem. __________________ 81 camaro 355 4/spd 342 posi my first love. 67 swb step 454/4spd ott 373 posi 4/7 drop. 2000 s10 zr2 little blue truck that never gets stuck. '74 heald super bronc vt8. tecumseh powered moon rover.

10-14-2015, 09:03 AM	#5
Tom Vogel 2WD Jimmy Join Date: Mar 2005 Location: Davis County, Utah Posts: 2,564	Re: Air bags and trailing arms?? Early Classic Enterprises has the perfect setup. Works awesome.

10-14-2015, 09:31 AM	#6
72kool Registered User Join Date: Dec 2012 Location: kearney nebraska Posts: 613	Re: Air bags and trailing arms?? slomotion, do you have pictures and more info on what bags you have? im wanting to use the style i can bolt right where the springs are. i have thought about using a rear sway bar anyways so that wont be an issue. i also have the rear overload springs so that is there as well. i want to run the air lines to fill ports in the bumper and adjust them my self. dont need the compressor or anything. just want to have a smooth ride and load support when needed

10-14-2015, 03:06 PM	#7
72kool Registered User Join Date: Dec 2012 Location: kearney nebraska Posts: 613	Re: Air bags and trailing arms?? Also would i need to get a special trac-bar or anything ? im not wanting to lower this extremely but if i wanted to run it lower to just level it, would that be an issue with everything else stock? sorry for dumb questions but im new to the air bags and lowering. usually do lifts and have only installed the load helper bags on new trucks



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