Smoothing out Dually rear? Airbags?

[ZZ4x4]

Well I got new '04 Chevy Dually 4x4 a couple weeks back and I'm trying to get the thing to ride smooth when unloaded. It's got the helper springs on top of the leaf pack and the overload spring below. Something back there clunks over the big bumps and the whole rear axle seems to bounce a lot. I installed velvet-rides and RS9000s and have gotten it quite a bit better overall, but since the velvet-rides make the rear of the springs a little closer to the helper spring stops, there is even more slapping and banging over mid size to large bumps.
I am considering removing the helper springs and possibly the overloads and adding some air-bags. Any thoughts on whether this will give a soft ride?
Thx,
jeff

 

[Pookster]

put a small piece of plado wrapped loosely in saran wrap

stick it between the springs- You might want to duct tape it lightly so it doesnt fall out.

Go drive around on said bumpy roads.

Look at plado. See how far it compressed.

 

[ZZ4x4]

Yeah, I thought about rolling up a sock and duct taping in between the helper spring and the hard-stop just to see if the banging went away. I do know the helper is contacting the stops because there are fresh clean marks in the road grime that accumulates on the leaves. I think the Playdoh will just squish out completely since the spring ends are hitting the stops.

 

[Seventy4Blazer]

you can remove the rear upper helpers and install air bags from the top of the spring over the axle to the frame. get online and search for firestone airbag kits.
lots of stuff out there.
i am looking into doing the same thing.
Grant

 

[ZZ4x4]

Cool. That appears to be the concensus among the other guys who have GM duallies I talked to. I'll remove the helpers this weekend! /forums/images/graemlins/waytogo.gif

 

[K30CJ]

My old crew has a set of killer leaf packs from a dually camper, with nine thick leaves. Let me tell you, they do not ride nice. /forums/images/graemlins/frown.gif They are great for when I tow my heavy gooseneck trailer, because you can't even see that the truck dropped any. Going to work on the crappy backroads beats the heck out of me though. New tires and shocks with the lift helped. I am thinking about swapping to a softer set of leaves, and adding airbags to carry the weight of the trailer when needed. That seems to be the best compromise. /forums/images/graemlins/waytogo.gif Let us know how you like the results!

 

[ZZ4x4]

Well, just to post the results of this weekends fiddling. PROBLEM SOLVED!!!!

The ending config on the rear end is:
-Dually tires set at 65psi
-Helper springs on top of spring pack removed
-Velvet ride shackles installed
-Rancho RS9000x installed. Set on level 4

The ride is nice and smooth now. It just cushes over slow speed bumps. Its actually softer than the front now. When I hit bigger bumps I can feel the spring rate firm up when the bottom overloads come into play. I don't think I need airbags even now, but if I wanted an even softer ride, I'd pull the lower overload and add small lift blocks and airbags.
I highly recommend this set up compared with the buckboard stock set-up.
Jeff

 

[imiceman44]

[ QUOTE ]
Well, just to post the results of this weekends fiddling. PROBLEM SOLVED!!!!

The ending config on the rear end is:
-Dually tires set at 65psi
-Helper springs on top of spring pack removed
-Velvet ride shackles installed
-Rancho RS9000x installed. Set on level 4

The ride is nice and smooth now. It just cushes over slow speed bumps. Its actually softer than the front now. When I hit bigger bumps I can feel the spring rate firm up when the bottom overloads come into play. I don't think I need airbags even now, but if I wanted an even softer ride, I'd pull the lower overload and add small lift blocks and airbags.
I highly recommend this set up compared with the buckboard stock set-up.
Jeff

[/ QUOTE ]

I just saw this post but yes, that is what my buddy did, he has the air bags but didn't install them since he didn't have time and ow he thinks he will not install them at all.
He has an encosed trailer for his race car and he tows it with no noticeable sag in the rear.
I am planning on doing the same on mine now.
/forums/images/graemlins/thumb.gif