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'21 3500 Rear Air Suspension - Smoooth Ride!

Brutal_HO

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Interesting....will it let you drive in that mode? I should probably clarify that when I made the slight adjustments to the sensors I could easily push my fingering the side of the bag (as opposed to it being firm). There very well could be a few pounds in them.

No,

You cannot drive in any mode that alters the ride height except Alt Trailer Height.

Bed Lowering, Jack, Alignment modes all cancel over 8MPH. The latter two just lock out the air system from altering pressure.
 
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CdnHO

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LOL...I was afraid that someone might ask me this question. I always have to think it through. I believe the sensor gets turned counter clockwise to command less pressure for a given height.
I am trying to get the maximum clearance from the bed rails to the fifth wheel. I want the truck as low as possible and figured there might be some adjustment in the sensors to give me a bit more.
 

CJM

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Has anybody installed gauges so that you can see how much pressure is in the bags?
 

roegs

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Thought I'd give an update to my original findings. I'll once again preface by saying that these are my findings only. I'm all ears if someone is able to provide additional information on how this system operates. I'd also be grateful if anyone is able to provide the section describing Rear Air Suspension from the RAM Shop Manual.

I'm very satisfied with how my truck (see sig) rides both empty and loaded. Loaded in my case is a Grand design 2930RL S-Class Solitude with approx 2500 lbs pin weight. While some may say 'its a 3500 and is supposed to ride stiff - get over it' my reply is that its also my daily driver and I know that with some work these trucks can be made to ride better.

My definition of a smooth unloaded ride? Prior to any of the things I did, I noticed that the rear was much stiffer than the front. When going over a bump the front would be fairly smooth while the rear would jolt my behind. After the adjustments etc, my rear suspension now feels just like the front. While it will never ride like a half ton, the sharpness of the ride is much more reduced.

Since I last wrote in this thread, we've towed the 5th wheel approx 500 miles which has allowed the rear suspension to settle. While my drivers side bag was still soft, it was not as supple as the passenger bag was. My assumption all along has been to have the bags empty when the truck is empty with full fuel. In my case the drivers bag has always been more firm than the passenger bag. To get the drivers side height sensor to let more air out of the bag, I needed to elongate one of the mounting holes. I used a dremel to remove a small amount of material as shown in the photo. After doing this, the drivers bag is now as supple as the passenger bag. Note that I've never anything to the passenger side of the suspension - my goal all along has been to get the drivers side the same as passenger via adjustment of the height sensor.

In summary, my combination for a very acceptable ride empty is the following:

1. Height sensors adjusted so that both bags are supple when truck is empty and fuel full.
2. Rear tire pressure is 42 lbs or less - note that I have the 20 inch wheels on mine. Either way, take advantage of the load range charts. There is no reason to keep the rears at 80 lbs! Front air pressure is 60 lbs.
3. Keep a full fuel tank - this seems to give the best ride.
 

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gimmie11s

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Nice... i keep meaning to order the adjustable rods to manually adjust air bag pressure, but it keeps slipping my mind... maybe today.

 

Nick

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I checked mine and both arms are parallel to the frame and the bags are pretty solid with the same amount of air pressure near as I can tell .
 

roegs

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I checked mine and both arms are parallel to the frame and the bags are pretty solid with the same amount of air pressure near as I can tell .
Is the truck empty or loaded? If both bags are firm with an unloaded truck, I'd think you'd have a very firm ride.
 

Nick

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Check out Revel performance .
Totally adjustable sensor arms .
 

Nick

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I should say the rod that comes off the arm connecting the sensor to the axle . mounted with Ballstuds at each end . Billet aluminum completely adjustable .
 

roegs

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Revel are the ones Gimme11s mentioned above. He included a link.
 

Nick

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I shot Revel an E mail and they said their connecting rods will only raise the suspension . Thinking how mine is set up you would still have to move the sensor arm regardless.
 

gimmie11s

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I shot Revel an E mail and they said their connecting rods will only raise the suspension . Thinking how mine is set up you would still have to move the sensor arm regardless.

I suppose that is true if your default unloaded position is a fully deflated airbag (this is how my truck operates unloaded).

However, once you put a load in the bed or on the hitch, those revel links will allow a wide range of adjustment.
 

Nick

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I owned Class 8 Trucks for many years with air ride . The sensor arm always pivoted and you could adjust the ride height by moving the rod that was attached to the rear axle at one end and the sensor arm at the other. When unloaded bobtailing they would practically deflat themselves . You also flipped a switch that would completely exhaust the bags so you could couple to a trailer easier . Guess Ram thought the system was to simple .
 

CdnHO

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Nice... i keep meaning to order the adjustable rods to manually adjust air bag pressure, but it keeps slipping my mind... maybe today.

Anyone use these on a dually with air to lower the rear of the truck when towing a fifth wheel?
 

John Jensen

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After putting a level kit on my 3500 SRW with Air, I’ve had a thought regarding the Alt Trailer Height and also the Bed Lowering abilities. We are discussing keeping the airbags “deflated” for a better ride and adjusting sensors so they stay that way empty. BUT in my experience so far, the bed lowering doesn’t really work like the RAM informational video shows. And the Alt Trailer height may also be affected if the bags are not inflated prior to activating either of those systems?
When I tap on bed lowering, my bed only drops about an inch (maybe)...

Thoughts?

I did a 0.5” level kit in the front and my truck is sitting slightly higher in the front now, hoping it just needs to settle in a bit


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I believe you are working ok, My Alt Trailer height lowers 1 1/4" and like you, bed lowering does not seem to work when hitching my trailer.
 

John Jensen

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I shot Revel an E mail and they said their connecting rods will only raise the suspension . Thinking how mine is set up you would still have to move the sensor arm regardless.
Interesting. They have a PDF that describes how to lower.
 

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CdnHO

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Interesting. They have a PDF that describes how to lower.
Their instructions are confusing at best. I cannot find instructions that specifically address 3500 trucks with air suspensions. I bought a pair to lower my rear end an inch or two to give me a more level fifth wheel trailer. I have not installed them yet so hoping it works. They are however rediculously priced for what they are. But they are the only option I could find.
 

gimmie11s

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Their instructions are confusing at best. I cannot find instructions that specifically address 3500 trucks with air suspensions. I bought a pair to lower my rear end an inch or two to give me a more level fifth wheel trailer. I have not installed them yet so hoping it works. They are however rediculously priced for what they are. But they are the only option I could find.

Have you tried "alternate ride height" after you hook up? On my truck, ARH drops the rear by almost exactly 1.5" vs standard height.
 

Nick

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Their instructions are confusing at best. I cannot find instructions that specifically address 3500 trucks with air suspensions. I bought a pair to lower my rear end an inch or two to give me a more level fifth wheel trailer. I have not installed them yet so hoping it works. They are however rediculously priced for what they are. But they are the only option I could
 

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