Using air bumps as a replacement for air bags on long travel

**spazstic** · 02-25-2013 11:19 AM

So I've been looking at adding air bags to the rear of my truck since I tow and haul somewhat regularly and I'm always bottoming out the rear due to the Deaver springs. I also have bent the frame a little from some harsh hits while off roading with camping gear in the back

. I was planning on straightening the frame with a comealong, welding in a crossmember, and adding air bags and air bumps. But I'm thinking that rather than add the Ø2.00" x 2.5" air bumps, I can use the Ø2.00 x 4" air bumps and not use air bags. The travel on the air bumps would work as an airbag. When just derbing around I'd have my normal suspension with air bumps (I add less pressure in the air bumps). When I load up the back, I've got air bags (I add more pressure). Seems like a great way to have the best of both worlds, and I don't see any issue in doing this.

What do you all think? I see RPG did basically the same thing on the Raptor and it looks like it works pretty well.
A performance and towing suspension? | Raptor Performance Group

Otherwise I was going to fab up some mounts with the Firestone 9000 bags since they won't limit my travel. Pretty much like what this guy did on his Taco:
long travel air bags - Tacoma World Forums

**SE2000** · 02-25-2013 01:01 PM

I think a set of roadmasters may be a great solution for you.
If your frame is bent, get it straightened professionally. The comealong will probably do more damage

**spazstic** · 02-25-2013 02:04 PM

I checked out the roadmasters and I don't think it's really what I'm looking for. I don't want to change my ride when unloaded and I don't want to stiffen it up when empty. I do a lot of off roading, and this seems more meant for people who poke around town. That's why I thought the air bumps would be a good compromise...

The frame isn't bent badly. It's where the bracket on the frame that contacts the bump stop is. Because of a few hard hits, it's cause the frame to "twist" in that section, where the bottom of the frame is farther out than the top. I think I can hook the comealong up to the bottom of the frame on both sides, and crank it down until the frame is straight again. I'll do it with the bed on to prevent the frame from wanting to just bow in. If it takes too much force, I'll just leave it. It's been that way for a while and I haven't had any issue.

I'm still thinking the air bumps are the best solution here... unless I'm missing something about the Roadmasters. They just seem kinda... gimmicky to me.

**YotaDan** · 02-28-2013 11:29 AM

Another option you could consider is getting a set of Air Lift air bags for a 07+ Tundra, and using these new Daystar Air Bag Cradles.

This will allow you the use of an air bag when loaded, but you won't have to worry about tearing it when off-roading.

**spazstic** · 02-28-2013 01:24 PM

Cool! That actually seems like a great idea... I read up some about it on here:
Building - Tow-Haul-Chase Project Ford - Off-Road Magazine

And here:
http://www.cumminsforum.com/forum/to...ag-cradle.html

Sounds like the only downside is a "slapping" noise every time the bag contacts the cradle when off roading. I don't think it'd be a problem, since my Hi-Lift in the bed makes so much freaking noise I probably wouldn't even notice it.

Sounds like you still need bump stops though. I was thinking I could leave a little air in the bag and use that as a bump stop, but that's probably not the best idea? In that case, using the air bumps saves a little cash...

Edit: BTW, I have an 06 Tundra. I don't think the 07+ brackets would work.

**YotaDan** · 02-28-2013 05:09 PM

The kit for the 06 tundra does not use the correct style of bag. So you would need to modify the bracketry from a different kit.

**spazstic** · 03-01-2013 08:29 AM

Hmmm.... It wouldn't be a big deal for me to fab up my own bracket. But I'm starting to think that using the bumpstops is the better way to go. Seems simpler and better for what I'll be using it for (primarily offroading). I figure I will weld the can to the frame and then weld gussets to the can to distribute it over more of the frame. I also plan on boxing my frame in while I'm there.

**spazstic** · 03-12-2013 12:42 PM

Well, I decided to go with the air bumps. I ordered 2.0 x 4" for the rear, and 2.0 x 2.5" in the front.

Also ordered a 20" single row light bar while I was at it...

I'll post up some pics after I install them.

**spazstic** · 03-26-2013 11:36 AM

Installed the air bumps this weekend. I put Fox 2.0 x 2.5" on the front and Fox 2.0 x 4.0" on the rear. Used Synergy's air bump cans, since I liked the way they mounted better. I figured I could weld around the can without worrying about it deforming or causing the pinch bolts to not be able to tighten fully. This way I welded along the length and left the small area where the pinch bolt clamps unwelded.

I removed the bed in the rear and boxed in the frame along about a foot where the cans weld to. Pretty easy to do, created a CAD model of it (Cardboard Aided Design) and then cut 1/8" steel out with a plasma cutter I rented from Sunbelt rentals. It was $80/day out the door, but if you pick it up on a Friday afternoon you don't have to return it until Monday morning, and it's only $80 for the weekend then. Created the gussets and front strike plates the same way. Had to notch the gussets a little on the driver's side to fit around the brake lines.

Rear:

Front:

Unfortunately, on the front I mocked it all up by taking the tires off, placing the truck on jackstands, and then jacking up one corner until it lifted off the stands. I figured that was settled height, but was wrong. My 1" of gap turned into 1/4". So the air bumps are basically full time shocks on the front. I don't think this will be a huge problem, but time will tell. The ride isn't much different from without the air bumps, just a tiny bit stiffer but almost unnoticeable. There really isn't much room in the front to place these. I wanted to put the bumps out farther, so that they were contacting the lower arm closer to the wheel, but there just isn't room. I'll probably re-position them when I put long travel on... someday

The ride is awesome... I took the truck out and beat the crap out of it, and it just asked for more. Pretty much couldn't get it to bottom out. Areas where I would bottom out hard before, I smoothly rolled over. You do notice a little "slapping" noise coming from air bumps, as the delrin ends make contact with the pads.

I'll be taking it out to the Mojave Desert for a few days starting tomorrow, so I'll really get to put it to it's paces. Haven't tried loading it up yet, I'm curious to see how they work with a lot of weight in the back. Also got a set of 285/75/16 Treadwrights in. Putting those on today with my Spidertrax spacers. I've been in need of some new rubber for a while...

I'll post back up once I load it up with gear. Should ride a lot nicer with the bumps in. All bumps are at factory pressure - 150 psi I think, my gauge only goes to 100 psi and it's more than that.