Air bags or Timbren on lifted truck

[mep1811]

Has anyone fitted either airbags or the Timbren SES suspension kit to a lifted truck?

Towing my trailer causes the rear to drop three or so inches.

 

[terdrocket]

Plenty of us have airbags. It's not a hard task. It's just as easy as swapping out the rear springs.

 

[abuck99]

Nice set up.

What is the spring rate on your rears?

Timbrens are a much better option than airbags for how you use your truck. Airbags are fine for highway towing but not a reliable or durable choice for long term off road use.

 

[molanginaeda]

Air bags is the solution. Timbren is just like bumpstop. Once lifted, it's not as effective. I do have Timbren install on mine. Not towing as of yet, but I can tell timbren wont help to prevent sag (after lifting), but maybe use better as a bumpstop on rough trail.

 

[linuxgod]

Nice set up.

What is the spring rate on your rears?

Timbrens are a much better option than airbags for how you use your truck. Airbags are fine for highway towing but not a reliable or durable choice for long term off road use.

Several of us have airbags and offroad without issue. I've found they are very reliable after 50k miles and they don't affect suspension travel offroad when aired down.

 

[abuck99]

Definitely a debatable topic and various ways you can look at each application; both have their merits. Ok you mentioned 50k trouble free miles with airbags, how many trail miles towing heavy camp trailer with armored and fully packed truck like OP has pictured?

If I were OP and based his set up and intended use; I wouldnt trust airbags as a reliable or maintenance/trouble free solution for that job.

 

[TeCKis300]

I'm with others that airbags are the right solution here IMO. Timbren's are a jounce/bump stop and meant to address bottoming out rather than continual load support, even though they advertise otherwise. Using a jounce stop as spring rate augmentation is bad suspension tuning in my mind.

 

[TimCFJ40]

Definitely a debatable topic and various ways you can look at each application; both have their merits. Ok you mentioned 50k trouble free miles with airbags, how many trail miles towing heavy camp trailer with armored and fully packed truck like OP has pictured?

If I were OP and based his set up and intended use; I wouldnt trust airbags as a reliable or maintenance/trouble free solution for that job.

I've got airbags as well, with 30k miles with a mix of towing, off-road, and daily driver use. I'm curious what you base your opinion on the reliability of airbags on?

Long Haul trucks carry thousands of pounds hundreds of thousands of miles on air bags without issue. In an application as a secondary spring such as this, even if they did fail the worst thing that would happen is a saggy rear end...

 

[linuxgod]

Definitely a debatable topic and various ways you can look at each application; both have their merits. Ok you mentioned 50k trouble free miles with airbags, how many trail miles towing heavy camp trailer with armored and fully packed truck like OP has pictured?

If I were OP and based his set up and intended use; I wouldnt trust airbags as a reliable or maintenance/trouble free solution for that job.

Curious, have you use airbags in your truck? Not Range Rover air suspension (which is crap) but the Firestone or Airlift brand helper bags?

About half my miles each year are towing a 6000# trailer. Those are highway miles.

I don't do a ton of offroad driving. Mostly pothole-ridden city streets. Some of the other folks on the forum like indycole have them and do a lot more wheeling than I do and could provide better feedback. That said having run them for 50k miles I do not believe offroad driving is going to significantly contribute to airbag wear or failures so long as you keep a nominal ~3-5 psi in them. In fact I believe towing is much worse as you're highly pressurizing them and as the wear on the bags is largely the friction of the springs against the bags - and when they are pressurized to 30psi they do stretch a bit. This is my opinion based on my experience so you can disregard it if you'd like - my positive anecdotal experience is as useful as the negative experience some other person may have posted about on another forum... unless there's a large random sample set of airbag users it's all statistically invalid anyway.

If I was offroad and towing a ton I'd probably just get stiffer rear springs and/or progressive rear springs and dump the airbags. Airbags are good for supporting ride height when you have a huge disparity in vehicle weights where you can't get a spring that will cover everything - like my setup where I may run ~6800# (with me in the truck) around town, ~7300# with my wife and kids and dog, or ~8500# with everyone plus a trailer with a 900# tongue plus additional camping gear.

I can't speak to the Timbrens but my understanding is it's just a longer, soft bump stop and so unless you're riding on them they aren't going to help... and if you are riding on them you're probably doing it wrong.

To the OP:
Losing 3" in the rear is a lot. Is that all from the trailer hitch or is it also gear in the truck? What's the TW of the trailer? If it's at least 400-500# then the setup should leverage a weight distribution hitch if possible to shift some weight off the tongue and onto the front axle.

 

[afgman786]

Bags would definitely be a good option. Or if you're seeing sag even without the trailer upgrading the springs to a heavier load rating.

 

[abuck99]

Agree on springs: My first question to OP inquired about which spring rate he was running; still waiting for that detail.

FWIW I have Tibrens. It's more than a glorified bump stop; it provides for normal ride unloaded and when loaded, as it compresses it provides a progressive dampening effect; IMO they work great. I've considered bags, but I've read numerous posts on failed airbags- Firestone, and other brands ( popped bags, bags getting caught in springs, lines coming loose, lines splitting, bags loosing air etc) - possibly these are install errors, application errors bad luck etc who knows.

IDK- to me the decision boils down to context of use which from the picture of OP's set up would indicate more than light duty. For highway towing, light offroad use airbags would suffice. Rugged off road: assuming OP has a 7000lb+/- truck, towing a 3000lb +/- trailer, the last thing I would want to deal with is repairing/replacing a bag, fiddling with lines etc.

 

[RobW0]

I would be curious to know what the TW of that trailer is. It looks like most of the weight is in front of the trailers axle.

 

[molanginaeda]

I followed OP on IG. I know his overland/adventure journey. @RobW0 got a point. The TW of the trailer is toward front as the fridge, spare tires, kitchen gallery & alubox (storage) in front of the trailer axle. Hence the heavy TW and sag. I won’t say getting heavier rear spring will help because if the trailer unhook for basecamp, the heavier spring might cause stiffer ride. Maybe a variable rate rear coil can help. Airbag will be a solution for sagging remediation. Raise up the airbag Psi when towing on highway. Run lower psi on the airbag on trail.

 

[mep1811]

I have the 1300lb OME rear springs. I still need to measure the drop with a tape measure. It might not be what I think it is. I see the rear drop when I lower the trailer on the pintle.

The tongue weight from the factory is supposed to be 280lbs. Add another 100 lbs max for food and cargo. Just because I have Alu Boxes does not mean they are packed with heavy stuff. One has paper plates , napkins towels. The other box has a couple of extra propane and jet boil canisters.

I spoke to Firestone and they say their air bag for the 2013 200 Series is for a stock suspension and not a lifted one.

 

[linuxgod]

I have the 1300lb OME rear springs. I still need to measure the drop with a tape measure. It might not be what I think it is. I see the rear drop when I lower the trailer on the pintle.

The tongue weight from the factory is supposed to be 280lbs. Add another 100 lbs max for food and cargo. Just because I have Alu Boxes does not mean they are packed with heavy stuff. One has paper plates , napkins towels. The other box has a couple of extra propane and jet boil canisters.

I spoke to Firestone and they say their air bag for the 2013 200 Series is for a stock suspension and not a lifted one.

Yeah Firestone support are a bunch of tools. They won't even try to help you if you're not a stock suspension.

The stock LC suspension uses the Firestone 4164 kit, which has 10" tall bags and assumes you'll cut all 4 rings off the internal jounce stop. Just measure your rear lift (1-2") and then cut off *less* of the rings to compensate for the internal free height of the coil. You'll need to cut off either 2 or 3 rings.

 

[mep1811]

Yeah Firestone support are a bunch of tools. They won't even try to help you if you're not a stock suspension.

The stock LC suspension uses the Firestone 4164 kit, which has 10" tall bags and assumes you'll cut all 4 rings off the internal jounce stop. Just measure your rear lift (1-2") and then cut off *less* of the rings to compensate for the internal free height of the coil. You'll need to cut off either 2 or 3 rings.

So the bag fills the entire spring without bulging.

 

[linuxgod]

So the bag fills the entire spring without bulging.

At 5psi it doesn't really bulge, it just sits snugly inside the spring. The bag hangs from the internal jounce stop as the air line gets threaded through that, and at rest the bag should touch the spring perch on the axle. There's a good install writeup at LandCruiser 200 - Airbag Man Heavy Duty Airbags - Project 200... originally they used Firestone (what I run) but it seems they've switched to AirBag Man (which I think indycole runs)

If you inflate to 30psi+ the bag will stretch a bit - not squeezed all the way between the springs but if you try and remove the bag it's really hard because it has stretched a bit and will have a bit of a coil spring impression in it. In my experience it never really deflates back to original size, but when you go back down to a nominal PSI the spring can still compress - the reason Firestone recommends keeping a nominal PSI in them is so if the spring fully compresses it won't pinch the bag, though unless your airbags expand a LOT more than mine I really can't see how coil compression wouldn't just result in the bag squeezing itself into the coil fully - particularly since "full stuff" of your suspension does NOT mean the spring is fully compressed to where the coils touch.

Below is a photo of how they stretch. Note this is NOT in a 200, but it'll give you an idea.

 

[ColoradoSequoia]

I tow a trailer with progressive (or variable - I can never remember the difference) springs and timbrens. The timbrens are about 1.5 inches off the axle so when i hitch up my camp trailer, with a 900lb tongue weight, it presses the timbrens down onto the axle and keeps it level (also have a WD hitch).

They work really well assuming you get the correct bracket and length of Timbren. Timbren was very accommodating to get me the correct brackets after the first ones weren’t correct.

I have not used airbags so can’t speak to those. But they are cheaper. If I did it over again, I’d try airbags first just because of the price and adjustability. Then if they didn’t work, I’d move over to the Timbrens.