3500 SRW suspension

[Thisnthat]

I test drove a 22 3500 SRW short bed with air suspension. I was impressed with the ride and put a deposit down to buy it but the dealership had to fix a couple things first. After 3 months they never got it fixed and sent it to auction and refunded my deposit. I can't find another similar truck close to me but did find one with everything I want except the air suspension that is 8 hours away. Is the difference in the ride as significant as I suspect between the two suspensions? I can't find a 3500 SRW near me to test drive and compare myself. I have driven a 3500 drw with standard suspension and it's too harsh for my purpose but I suspect the dual wheels is a big part of that.

what trim level are you looking for? Granger of all places has a 23 Laramie with air ride. quite a few 23's showed up on Ram's website...even some tradesmans (noticed that you have to build the truck and then search inventory from the build for air ride to be a selectable filter)

2023 RAM 3500 Laramie Des Moines IA | Ankeny Waukee Grimes Iowa 3C63R3ELXPG625624

Research the 2023 RAM 3500 Laramie in Des Moines, IA at Granger Motors. View pictures, specs, and pricing on our huge selection of vehicles. 3C63R3ELXPG625624

www.grangermotors.com

 

[AH64ID]

When it was stock, the bags had just enough air to not be empty and could easily press a thumb about 1/2" into them. As soon as any kind of weight lowers the suspension the bags instantly air up to level. At that point the system functions as it should including the messages you described.

A thumb press isn't really that telling, as your thumb will vary from my thumb. What would be more telling is if you were resting on the overload bumpers in normal ride height or not. @roegs doesn't get anything out of bed lowering because he's already at that height in normal due to how his sensors are setup.

It's almost like the bags are non existent until the sensors detect a load then the system wakes up and assist.

Which isn't how the system has operated since it was introduced, nor how it is still discussed in the owners manual or in the spec sheets for dimensions.

Couple things you can try and add more data for taking it to Ram.

1) Ignition on, engine off. When you go into bed lowering mode do you hear any valves open and air dump?

2) Ignition on, engine off. When you select transport mode do you hear any valves open and air dump?

3) When you're loaded is there a ~1" ride height difference in NORM and ALT?

 

[jenninr]

After talking to Mark Dodge I went ahead and ordered a new 24 3500 CCSB with air ride. I comes out to just about $2k more than the used truck I was looking at and less than some other similarly equipped used trucks I saw out there. Right at 22% off MSRP with the Tread Lightly affiliate pricing added. Basically the 10% off rebate right now cancels out the MSRP increases over the last couple of years and the price comes out to about what I think a 22 would have cost with the discounts that were available at that time. Thanks for all the responses. I think there's some good info here to reference back to. I had to make a quick decision because the 10% off ends today.

 

[H3LZSN1P3R]

Sorry guys, the video was taking a while to upload and I needed to go to my daughters for dinner. Here is the video showing normal ride height, bed lowering mode, and alternate ride height.

Edit: The video is still currently processing so video quality will be poor until it's complete

Your system is out of adjustment notice your bed lowing symbol barely flashes showing its lowering that means the system has little to no air in it when there should be a minimum of ~10PSI.

 

[roegs]

The local dealer had a loaded Laramie 3500 CC SB SRW with air suspension so I went over and looked at it today. Both bags were relatively firm and overload rubber cushions were about 5/8" away from the lighter springs. After that I went home and using a floor jack lifting the hitch receiver on my truck figured I'd need 3/4" lift from the bags to get that same overload gap on mine. Guess that aligns with the 3/4" drop you guys are saying you get in bed lowering mode.

I also looked at the shop manual today via Tech Authority. They have a 3 day subscription you can purchase. The shop manual provided really nothing related to this discussion. Everything is done via their scan tool and calibration is done by measuring wheel well heights and entering them into the tool. The tool and control module do the rest from there. No detailed description on how the system works and there is no adjusting of the height sensing switches.

We leave for Florida next month with our 5th wheel. I'll probably play more with it then so I can also watch heights etc. with pin weight applied to the truck bed. I've become a whimp doing any outside work in winter weather.

 

[roegs]

In spite of the cold I couldn't wait and did some playing today. At this point I'm feeling like I hit the jackpot. I've only put on about 10 miles but there is a definite difference. In my opinion, this truck now rivals the GM HD trucks, which I believe have the best ride of the big 3 (although GM has their own set of weaknesses).

1. As mentioned above, I started out with bags deflated as much as adjusting the sensors allows. My verification of this is no change in height (measured at the hitch receiver) when in / out of Bed Lowering Mode.

2. I adjusted both sensors until I heard the bags inflate. For those who may try this, you need to wait a bit after moving the sensor. Changes are not applied to the bags immediately. After a couple of tries, I was able to get a change of 3/4" when in / out of Bed Lowering Mode. This seems to be the same amount others in this thread have seen.

3. Took the truck for a drive. Obviously everyone's thoughts on ride quality is subjective, but my butt-o-meter said that the overall ride was firmer than with bags deflated - but the jolt over parking lot speed bumps was less as the overloads were no longer kicking in due to the slight increase in ride height.

4. I was kinda frustrated and pulled into a parking lot and thought I'd try one more adjustment. I tweaked both sensors no more than a 1/16" in the direction of lowering the truck. Pulled back onto the road and after a few blocks was totally surprised. It felt much better than ever. When I got back home I did another measurement of bed lowering mode. Measured twice and I'm now at 5/16" when in / out of Bed Lowering Mode.

While I can still push my thumb into the side of the bags when parked, they're firmer than before when I had them deflated (as much as possible). I'll try this setting for a while and post back.

 

[Brutal_HO]

Bottom line is I think many air assist trucks were not setup properly from the factory and that's why we see so much disagreement on both the way the feature works and everyone's subjective perception on ride quality in the air assist trucks.

With low tire pressures (when not towing) my truck rides great* and I'm glad I optioned it.


*Exception is some concrete stretches of I-25 N&S of Denver and EVERYONE has that same garbage ride.

 

[Ionicbrick]

Bottom line is I think many air assist trucks were not setup properly from the factory and that's why we see so much disagreement on both the way the feature works and everyone's subjective perception on ride quality in the air assist trucks.

With low tire pressures (when not towing) my truck rides great* and I'm glad I optioned it.


*Exception is some concrete stretches of I-25 N&S of Denver and EVERYONE has that same garbage ride.

Yes sir! Not to mention the whole north end of 225!

I tow all the time so I don’t mess with pressures, but if you can that makes a difference too!


Sent from my iPhone using Tapatalk

 

[H3LZSN1P3R]

In spite of the cold I couldn't wait and did some playing today. At this point I'm feeling like I hit the jackpot. I've only put on about 10 miles but there is a definite difference. In my opinion, this truck now rivals the GM HD trucks, which I believe have the best ride of the big 3 (although GM has their own set of weaknesses).

1. As mentioned above, I started out with bags deflated as much as adjusting the sensors allows. My verification of this is no change in height (measured at the hitch receiver) when in / out of Bed Lowering Mode.

2. I adjusted both sensors until I heard the bags inflate. For those who may try this, you need to wait a bit after moving the sensor. Changes are not applied to the bags immediately. After a couple of tries, I was able to get a change of 3/4" when in / out of Bed Lowering Mode. This seems to be the same amount others in this thread have seen.

3. Took the truck for a drive. Obviously everyone's thoughts on ride quality is subjective, but my butt-o-meter said that the overall ride was firmer than with bags deflated - but the jolt over parking lot speed bumps was less as the overloads were no longer kicking in due to the slight increase in ride height.

4. I was kinda frustrated and pulled into a parking lot and thought I'd try one more adjustment. I tweaked both sensors no more than a 1/16" in the direction of lowering the truck. Pulled back onto the road and after a few blocks was totally surprised. It felt much better than ever. When I got back home I did another measurement of bed lowering mode. Measured twice and I'm now at 5/16" when in / out of Bed Lowering Mode.

While I can still push my thumb into the side of the bags when parked, they're firmer than before when I had them deflated (as much as possible). I'll try this setting for a while and post back.

The other big thing to remember bags need atleast some air (5-10 psi) to avoid damage as they do not have an internal bumpstop

 

[roegs]

The other big thing to remember bags need atleast some air (5-10 psi) to avoid damage as they do not have an internal bumpstop

I don't think its even possible to release all the pressure from the bags outside of physically opening up the pressure lines. It's a closed nitrogen filled system and I'd be surprised if RAM would allow a full dump of the bags.

 

[BilletWilson]

I don't think its even possible to release all the pressure from the bags outside of physically opening up the pressure lines. It's a closed nitrogen filled system and I'd be surprised if RAM would allow a full dump of the bags.

You can either pull the fuse to dump the air or install adjustable sensor arms to fill the bags to your preference.

 

[H3LZSN1P3R]

I don't think its even possible to release all the pressure from the bags outside of physically opening up the pressure lines. It's a closed nitrogen filled system and I'd be surprised if RAM would allow a full dump of the bags.

So there is a storage tank in the system?

 

[roegs]

You can either pull the fuse to dump the air or install adjustable sensor arms to fill the bags to your preference.

You can't do a full dump unless you deliberately go through the process of drain and refill again with nitrogen. There is a minimum retention pressure that stays in the system.

So there is a storage tank in the system?

Yes.

I purchased a 3 day subscription from Tech Authority. I attached the section describing how the system works. While there are many more details I would have liked to see it does give a good explanation. There is some wording in the document that appears to bleed over into other RAM air suspensions such as the one on the 1500, but the overall concept of our system is in there.

 

[BilletWilson]

You can't do a full dump unless you deliberately go through the process of drain and refill again with nitrogen. There is a minimum retention pressure that stays in the system.


Yes.

I purchased a 3 day subscription from Tech Authority. I attached the section describing how the system works. While there are many more details I would have liked to see it does give a good explanation. There is some wording in the document that appears to bleed over into other RAM air suspensions such as the one on the 1500, but the overall concept of our system is in there.

The bags will dump to the point that they will physically feel and act empty. I wouldn't suggest actually opening the system to relieve the nitrogen.

 

[AH64ID]

I don't think its even possible to release all the pressure from the bags outside of physically opening up the pressure lines. It's a closed nitrogen filled system and I'd be surprised if RAM would allow a full dump of the bags.

Bed lowering and transport mode dumps all the air.

The 1500 uses a closed system, but the 3500 uses an open system. The intake/dump hose is between the cab and bed on the passenger side. You can feel it dump air when lowering, suck air when filling the tank, and hear it do a moisture purge when you first start driving.

 

[Brutal_HO]

Bed lowering and transport mode dumps all the air.

The 1500 uses a closed system, but the 3500 uses an open system. The intake/dump hose is between the cab and bed on the passenger side. You can feel it dump air when lowering, suck air when filling the tank, and hear it do a moisture purge when you first start driving.

Interesting, I'd always assumed it was a closed system and the noises were just air rushing into the tank during a dump.

As to the 1500, there's been some debate recently on 5thgenrams about that, given 2 known items.

1. There's a breather valve behind the driver(?) side taillight
2. Someone said they heard air dumping and was concerned

 

[AH64ID]

Interesting, I'd always assumed it was a closed system and the noises were just air rushing into the tank during a dump.

As to the 1500, there's been some debate recently on 5thgenrams about that, given 2 known items.

1. There's a breather valve behind the driver(?) side taillight
2. Someone said they heard air dumping and was concerned

Interesting on the 1500's.

I don't remember how many times I did it one day, but I was able to go from normal height to transport mode and back to normal close to 10 times without the compressor ever running and the air dumping overboard at each cycle. The compressor then pulled from the atmosphere to refill the reservoir.

 

[roegs]

The 1500 uses a closed system, but the 3500 uses an open system......

Interesting, I'd always assumed it was a closed system and the noises were just air rushing into the tank during a dump.

I'm in no position to argue, but the RAM Service Manual document I uploaded in my earlier post clearly states that the 3500 is a closed system.

 

[Brutal_HO]

I see a few conflicting, or less than detailed statements in the doc.

did you drill into this "refilling" link?

 

[AH64ID]

I'm in no position to argue, but the RAM Service Manual document I uploaded in my earlier post clearly states that the 3500 is a closed system.

Yes it does, but it also says the compressor is used to refill the reservoir from the atmosphere.

The verbiage in that document has come up in other threads, I can't recall if on HDRams or on TDR, but it's a typo.

You can stick your finger over the intake/exhaust air hose and feel it vent when the bags deflate and suck when the compressor runs, both are the best indications that it's an open system.

I've read that you must refill the system when the reservoir is vented because the compressor will run long enough that the ASCM will think there is a leak and set a warning.