Rear axle to frame distance

[1992gen1_fan]

Got a set of air bags for the rear on my truck. What is the factory distance from the top of the axle tube to the bottom of the frame rail directly above the axle on a I/C w350 with the tall blocks?

I think I need to raise the frame to stock height to mount the brackets since I have the factory overload leafs and the heavy bed has the springs squatted.

[PToombs]

I jacked my truck up until the bed was just higher in the rear and then mounted the bags. I was using the bags to compensate for sacked out springs. When I put in the new springs and pulled the bags I gained a little over an inch of unloaded height at the rear. FYI, I had to run 40 psi in the bags to hold the truck level, and it rode like a lumber wagon. It rides nicer with the new springs than it did with the bags.

[1992gen1_fan]

Ok, my truck sits about level now but if I load it down it squats alot where with the factory bed it sit about level with a load. I don't mind if it rids a bit rougher. I plan on new leaf packs in the future when I can afford them but for now this should help. If I end up driving at night with a load I would like to be able to see the road instead of the tree tops

[Tacoclaw]

Check the installed height numbers on those bags, I wouldn't be surprised if their sitting at almost completely extended in that pic. I have a similar set and they claim that have like a 3" up travel installed height.

[PToombs]

Yeah, the upper mount is upside down, that will squish them down when he flips it over. That's about the full extension height in that pic.

[1992gen1_fan]

In that pic the bag is just sitting there not attached. Just to show how low the frame is in correlation to the upper mount. The instructions say the distance between the upper and lower mounts must be 5"-7". In the pic they're at 7". I set the upper mount how it showed in the instruction pic.

[PToombs]

Well, you were right! I just went out to the barn to look at my truck and the mount is that way. Sorry about that! I was looking at your pic all wrong, thinking it had to be mounted to the frame of the bed because of where it is sitting in the pic. The other thing that threw me off is you have helper springs and mine doesn't, so your base is 2-3 inches higher than mine too.
I need to start paying more attention.

[1992gen1_fan]

No problem. I should've explained better in my original post, my bad .

I might just raise the frame to where the upper bag mount can attach and call it good. Judging by the looks of it I'll always need to keep some pressure in them to prevent bottoming out. In an older post I read about attaching them to 1 gal reservoirs to help the ride quality.

This kit is a AirLift Load Lifter 5000 BTW.

[PToombs]

I think mine are the Firestones. I would jack it up to level or a little above and then squash the bags down and mount the bracket. I squashed the bags and then put a plug in the hole to keep them compressed while I worked. It was easier than fighting the bag while marking holes.
IIRC the instructions say you need to leave air in to protect them. The tanks you are referring to are called "ping tanks".

[1992gen1_fan]

Ok, thanks for the tips. Thats right, "ping tanks" are what I read about.

The min is 5psi but I'll probably need to keep quite a bit in them because of this heavy a$$ flatbed. Its almost a load its self .

I'll let ya'll know how it turns out.

[1992gen1_fan]

Got the bags installed today. In the instructions it said that they support about 40lbs of load per 1 psi so I aired them up to 55psi while it was still jacked up. I let it off the jack and that put the pressure to about 65psi. I took it for a test run and to my surprise, it rides WAY better than it did. Alot smoother, and my dirt road is all washed out from the flash flooding we got the other night. Not at all what I expected . Anyway looks like I might not need the "ping tanks".

The truck "sways" or rocks back and forth a bit now but I think the rear shocks are just getting bad.

[PToombs]

Do you have a single fill for both bags? If so, that could cause the sway. When you go around a corner the air will transfer from the side that's leaning to the other.

Or the shocks are getting bad.

[1992gen1_fan]

They fill seperatly. Thats a good point though.

[1992gen1_fan]

I tried them with 80psi, the truck did ride a touch rougher but that got rid of most of the "sway" and still rides noticeably better than without the air springs.