Timbrens, who tows with them?

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
^^ Anthony pretty much nailed it.

We could go down a heck of a rabbit hole if you guys want? Basically giving thr facts/reasons behind why dampening is so hard to do
 

Don Dorfman

New member
Jul 24, 2017
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^^ Anthony pretty much nailed it.

We could go down a heck of a rabbit hole if you guys want? Basically giving thr facts/reasons behind why dampening is so hard to do
I run airlift bags 5psi all the time except when loaded then 35. I have adjustable fox shocks, easily changed to higher setting when loaded, with separate reservoir. Silastic shackles. When loaded my lbz 2500 has a 5th wheel hitch weight of 3200, total 15,200. I also have a trailersaver bd3 hitch which is air cushioned. My ride and stability are excellent loaded and unloaded. I also have an added a supersteer rear Trac bar for side to side differential stability. No complaints just several years of messing around to find the balanced system
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
23,033
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Phoenix Az
I run airlift bags 5psi all the time except when loaded then 35. I have adjustable fox shocks, easily changed to higher setting when loaded, with separate reservoir. Silastic shackles. When loaded my lbz 2500 has a 5th wheel hitch weight of 3200, total 15,200. I also have a trailersaver bd3 hitch which is air cushioned. My ride and stability are excellent loaded and unloaded. I also have an added a supersteer rear Trac bar for side to side differential stability. No complaints just several years of messing around to find the balanced system

Am im sure it works well to your liking which is great!

But since you posted in here about it, lets break it down some.

Your shock: those clickers you have on them are strictly for compression, they do not add any additional rebound dampening. If you had that ability, it would be found on the bottom of the shock at the rod end. Being that utv shocks are the only ones that come that way or high dollar specialty order ones, i fear you do not have that ability which means only half the problem is solved.

Your shackles: effectively you reduced your spring rate of the leaf springs because the rubber bushing inside that shackle is now the one taking most the movement. This is whats helping make the 5psi in said air bags feel much nicer when unloaded. Reducing compression on the shocks helps too (to an extent). Take the bags off all together, it will ride even better as well.

Your air bags on both hitch and truck: you have compounded the bags and basically added suspension with that hitch. This is alot like a dual rate spring rate on a coilover. So for example, of a single spring is 10” long at 200lbs/inch, then you add another on top that is 10” long and 200lbs/inch, the overall effective spring rate is 100lbs/inch but 20” long overall. Youve done the same on a progressive rate air bags, making them dual rate (not 100% but very close) which is close to my statement about running a big air bags on the back with a link setup and no leafs. Your shackles have not affect here either as they hit their stops as soon as a load is put on them and all force is transferred to the springs

Your track bar: nothing bad to say there at all. Our limited suspension travel doesnt let those issues show if setup right.



So its not a setup i personally i would want to go with because thats a far more expensive route for the effectiveness when i can instead pin point the issue, have my cake and eat it too so to speak. 10 years and 50k+ miles on my toy hauler show shes holding up just fine as well BUT that was before the tongue weight increased when i took the tracker out. Suspension on the truck had proper travel and shock dampening was working well (they are going to need to be changed at this point though).
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,886
800
113
Central OH
I run airlift bags 5psi all the time except when loaded then 35. I have adjustable fox shocks, easily changed to higher setting when loaded, with separate reservoir. Silastic shackles. When loaded my lbz 2500 has a 5th wheel hitch weight of 3200, total 15,200. I also have a trailersaver bd3 hitch which is air cushioned. My ride and stability are excellent loaded and unloaded. I also have an added a supersteer rear Trac bar for side to side differential stability. No complaints just several years of messing around to find the balanced system

Might seem like an odd question, but are you the cylinder head guy?
 

Ridin'GMC

I like red
May 20, 2010
715
50
28
MA
So I'm trying to understand more clearly for your suspension setup. If you were to run 4 link air bag with no leafs, it would ride great unloaded or loaded with the proper bag size such as sleeves bags but then you would be limited to suspension travel and the progressiveness? Meaning 4 link bags with no leafs is better suited for lowered or static applications for towing and running empty? As in running leafs with proper shocks setup will net you the suspension travel you're looking for?

I'm not sure if it would help you, on my other truck, I have 6" deaver progressive springs with Bilstein 5160 and they rode great empty and loaded. Better than the stock leafs with the 5100s. With the factory setup, I hated how the rear end would kick back riding empty going over potholes that's riddled in the New England area. Once I switched over to the deavers with the 5160, it didn't kick as bad as the factory did and towing felt a lot more comfortable but I never did a 5th wheel. My lift was only a 6" so I used the 3" lowering shackles to compensate to level out with the 6" lift springs because I thought I would eventually change the front suspension to a 7-9". Just bumper pull, the heaviest I've towed was 18k for the bumper pull and it didn't sag as bad as I thought it would.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
23,033
8,045
113
Phoenix Az
So I'm trying to understand more clearly for your suspension setup. If you were to run 4 link air bag with no leafs, it would ride great unloaded or loaded with the proper bag size such as sleeves bags but then you would be limited to suspension travel and the progressiveness? Meaning 4 link bags with no leafs is better suited for lowered or static applications for towing and running empty? As in running leafs with proper shocks setup will net you the suspension travel you're looking for?

I'm not sure if it would help you, on my other truck, I have 6" deaver progressive springs with Bilstein 5160 and they rode great empty and loaded. Better than the stock leafs with the 5100s. With the factory setup, I hated how the rear end would kick back riding empty going over potholes that's riddled in the New England area. Once I switched over to the deavers with the 5160, it didn't kick as bad as the factory did and towing felt a lot more comfortable but I never did a 5th wheel. My lift was only a 6" so I used the 3" lowering shackles to compensate to level out with the 6" lift springs because I thought I would eventually change the front suspension to a 7-9". Just bumper pull, the heaviest I've towed was 18k for the bumper pull and it didn't sag as bad as I thought it would.

I wouldnt say its better suited. You can make air bags work for long travel too, you just put the bag on the lower link and size it accordingly.

What im stating is that adding bags to the stock leaf setup automatically limits travel just due to how they package them in a truck and due the small size, they have high spring rates even with 0psi at static ride height (soon as it start’s compressing, psi start’s increasing in the bag). Dampening that highly varying spring rate sucks ass too which causes rear end bounce when loaded over large bumps.

The deavers dont have the load capacity i need when loaded. Theres 2500lbs at the pin which will squat the truck worse than it is now.





As for timbrens, talked to a few people locally that run them and sounds like they offer what im after. Going to order a set up today
 

2004LB7

Super Moderator
Staff member
Dec 15, 2010
8,551
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Norcal
I wouldnt say its better suited. You can make air bags work for long travel too, you just put the bag on the lower link and size it accordingly.

What im stating is that adding bags to the stock leaf setup automatically limits travel just due to how they package them in a truck and due the small size, they have high spring rates even with 0psi at static ride height (soon as it start’s compressing, psi start’s increasing in the bag). Dampening that highly varying spring rate sucks ass too which causes rear end bounce when loaded over large bumps.

The deavers dont have the load capacity i need when loaded. Theres 2500lbs at the pin which will squat the truck worse than it is now.





As for timbrens, talked to a few people locally that run them and sounds like they offer what im after. Going to order a set up today
I know we are kinda beating a dead house here. But what about air bags with an external air reservoir to dampen that high spring rate? Basically an air tank the fill lines run to so you get a little more compression with less pressure rise. But you can still adjust the pressure to suit your load
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
23,033
8,045
113
Phoenix Az
I know we are kinda beating a dead house here. But what about air bags with an external air reservoir to dampen that high spring rate? Basically an air tank the fill lines run to so you get a little more compression with less pressure rise. But you can still adjust the pressure to suit your load

You could but now the hose is the restiction and limited on cfm flow, it would need to be fairly large and then that becomes a space issue. The dodge ram air system kinda works that way but not well
 

malibu795

misspeelleerr
Apr 28, 2007
9,212
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in the buckeye state
If one wants to run legitimate air ride suspension build it around one of these bags.
Iirc the W013588900 is what kelderman used on their 800/900 chassis 4 link
The W013585770 is used on ride well 244 8k suspension.
I have full PDF specs on both bag, some server is down and won't let me upload them
 

gmduramax

Shits broke
Jun 12, 2008
4,185
326
83
Nor cal
I know we are kinda beating a dead house here. But what about air bags with an external air reservoir to dampen that high spring rate? Basically an air tank the fill lines run to so you get a little more compression with less pressure rise. But you can still adjust the pressure to suit your load
I tried this on my dad’s truck, works really well. But not great
 

Dozerboy

Well-known member
Jun 23, 2009
5,088
682
113
TX of course
I have RAS on my '22 for a year now. I'm happy with them. I didn't want bags for the reasons you mentioned and I don't feel the are durable enough for what I want. The way I destroy the factory Jonce stops and didn't want Timberlands. My truck has 2k lbs in the bed at all times just about.
 

duramaxmt

New member
Apr 15, 2016
10
1
3
Anaconda mt.
have a set of used timbren for sale 2016
gmc 3500 SOLD
 

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CDmax16

Member
Mar 3, 2018
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NNV
have a set of used timbren for sale 2016
gmc 3500 SOLD
Thank you Sir, got them yesterday.

I’m ditching air ride bags with the internal jounce and switching to Timbrens. I have been thinking about it for a while when this thread popped up and sealed the deal. Really enjoy the site, always learning something.
 

68ss

Active member
Dec 30, 2019
156
75
28
Brooklet, Ga
Thank you Sir, got them yesterday.

I’m ditching air ride bags with the internal jounce and switching to Timbrens. I have been thinking about it for a while when this thread popped up and sealed the deal. Really enjoy the site, always learning something.
I have towed with them for about 4 years. I really like mine.