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  1. Vehicle Suspension
  2. Pacbrake
  3. Air Springs
  4. Towing/Load Leveling
  5. Rear Axle Suspension Enhancement
  6. Heavy Duty
THIS ITEM IS NOT A FIT FOR
2009 Chrysler 300C
etrailer Installation
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Pacbrake

Pacbrake Alpha HD Pro Air Bag Suspension Kit w/ Internal Jounce Bumpers - Rear Axle - 5,000 lbs

Part Number: PB37CJ
In Stock
$731.39
Retail:$812.66
You Save: $81.27
Vehicle Suspension
Not Confirmed to Fit

2009 Chrysler 300C

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5,000-lb Capacity. When the load gets heavy, your truck shouldn't feel like it's fighting you. These air bags help you stay level and in control so you can tow with confidence and handle heavy loads without second-guessing your suspension. Great Prices for the best vehicle suspension from Pacbrake. Pacbrake Alpha HD Pro Air Bag Suspension Kit w/ Internal Jounce Bumpers - Rear Axle - 5,000 lbs part number PB37CJ can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (12)
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Pacbrake Vehicle Suspension - PB37CJ

  • Air Springs
  • Towing/Load Leveling
  • Rear Axle Suspension Enhancement
  • Pacbrake
  • Heavy Duty
  • Suspension Only

5,000-lb Capacity. When the load gets heavy, your truck shouldn't feel like it's fighting you. These air bags help you stay level and in control so you can tow with confidence and handle heavy loads without second-guessing your suspension.


Highlights

  • Custom Fit for Your Vehicle: Precision brackets bolt to factory attachment points.
  • 5,000-lb Load Support: Reduces rear-end sag, sway, and bounce for better handling under load.
  • Ride Smooth When Unloaded: Internal jounce bumpers protect ride quality with no air in the bags.
  • Adjustable Air Pressure: Set support between 0 psi and 100 psi depending on your load.
  • Complete Kit, Minimal Drilling: Includes laser-cut brackets, push-to-connect fittings, and all hardware.
  • Ready Now, Upgrade Later: Use manual inflation or connect to onboard air when you're ready.

Features to know about

Control and Cushion When It Counts

Heavy trailers, full beds, gear piled high, it all changes how your truck handles. Without the right support, you feel it immediately: sagging in the rear, poor handling, and a ride that gets unpredictable fast. This air bag system puts you back in control with up to 5,000 lbs of load-leveling support it helps reduce squat, improve steering response, and keep your truck stable when the weight stacks up.

Comfort When Unloaded, Control When Loaded

Every haul is different, and your suspension should keep up. Alpha HD Pro air springs give you full control over ride height and firmness with adjustable air pressure from 5 to 100 psi. Driving unloaded? The built-in jounce bumpers let you safely run at 0 psi for a smooth, factory-style ride with no harsh rebound. Hooked up to a fifth wheel or hauling a bed full of gravel? Add air to level the truck and keep handling tight. With manual inflation valves included, tuning your suspension for the day's load is straightforward and dependable.

Built Tough for Work and Weather

Air bags are only as strong as their weakest link. That's why Alpha HD Pro bags are reinforced all the way through with heavy-duty end caps, 20 internal support wires, integrated jounce bumpers, and powder-coated steel brackets. Toss in corrosion-resistant hardware and thick roll plates, and you've got gear that holds up to real-world hauling through heat, cold, salt, and slop.

Installation That Doesn't Waste Your Weekend

Adding serious load support shouldn't mean losing a whole weekend. The precision laser-cut brackets are designed to bolt cleanly to your truck's existing mounting points with minimal drilling. Just smart engineering that fits the way it should which is perfect for the DIY-er. Manual valves mount through license plate fastener holes or a location of your choosing (which may require drilling). With high-quality fittings, pre-bent brackets, and mounting hardware included, you'll be back on the road in just a few hours without a trip to the fab shop.

Flexible for Today, Ready for What's Next

This kit is designed to work with your setup today and grow with your upgrades tomorrow. You can inflate manually through the included air valves right out of the box, no extra parts needed. Already have an onboard compressor? The Alpha HD Pro system connects easily to most existing setups.


Want to step up to an all-in-one kit with air bags, compressor, and wireless controller in one package? We've got you covered with Pacbrake's On Demand Kit (PB29YV).


Looking for a complete system with onboard air storage too? Upgrade to one of the "Ultimate" Kits (PB82YV) or (PB22YV) with air bags, compressor, wireless controller, and 1/2-gallon or 2-1/2-gallon air tank for added versatility.

Specs:

Weight & Capacity:

  • Load support: up to 5,000 lbs of additional leveling support
  • Air springs will not increase your vehicle's weight-carrying capacity. Do not exceed the manufacturer's recommended weight limit.

Adjustability:

  • Air pressure range: 5 psi - 100 psi; 0 psi when unloaded

Estimated Install Time:

  • Professional install: 1-1/2 hrs
  • DIY: 2-1/2 hrs, depending on tools and experience. Plan for extra time if this is your first air spring install or you're working in a driveway setup.

Warranty:

  • Limited lifetime on air bags
  • 2-Year or 24,000 miles on mounting brackets, fasteners, and spacers

Included Components:

  • Pacbrake Alpha HD Pro air springs (rear axle, with internal jounce bumpers)
  • Precision laser-cut powder-coated steel brackets
  • Grade 5 plated hardware
  • Air lines, push-to-connect fittings, inflation valves, installation instructions


HP10731-J Packbrake Alpha HD Pro Rear Air Spring Suspension Kit - Manual Inflation Valves - 5,000 lbs

Installation Details PB37CJ Installation instructions

This Product Fits The Following Vehicles




Video of Pacbrake Alpha HD Pro Air Bag Suspension Kit w/ Internal Jounce Bumpers - Rear Axle - 5,000 lbs
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Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Review of Pacbrake Vehicle Suspension - Alpha HD Pro Rear Axle Air Bag Suspension Jounce - PB37CJ

Ratings & Reviews

4.3

12 reviews
5 Stars
(9)
4 Stars
(1)
3 Stars
(0)
2 Stars
(0)
1 Star
(2)
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by:
2026 Chevrolet Silverado 2500
This is a very nice kit. I installed on my new 2026 Silverado 2500hd. Installation was pretty straight forward, but still took a bit of thinking. After everything is mounted correctly there is a slight lean to the bags (not completely perpenticular to the mounting plates). I called Pacbrake support and they assured me this was normal and nothing to be concerned with. I had the equivalent AirLift kit on my 2007 Silverado 2500hd and I think I like the Pacbrake kit better. Everything seems a bet "beefier".
by:
2025 Chevrolet Silverado 1500
The only reason I bought this kit is because I was told I could put zero psi when not towing and I would not lose the factory suspension comfort. That information was wrong its a horrible ride now and I regret getting these bags. Was also told that they don't off this kit without the stainless upgrade so I had to buy it, but when it shipped there was a separate box with the stainless kit and they regular stuff was in the same box as the bags feels like I got ripped off on this deal
by:
I have no problems with the quality or the install. My one problem is the instructions, when you order the stainless steel kit, it comes with a separate box to replace the hardware. That's totally fine, but it would be nice if they could work that in the instructions for when to install the stainless steel airlines because you can install them at the same time that you can the push in plastic lines. Besides that, these are an insane set of airbags. When I ride at zero psi cuz I got the ones with the internal jounce bumpers, I did not expect this but it smooths out my ride. That's a super huge plus.
by:
2021 Ram 2500
Great set up. Easy to install. Much better than the Timbren bump stops.
by:
verry easy install, everthing was in the package. just installed it. will see how it works under load. under an hour install time.
by:
2018 Ram 2500
It was easy to order and the stuff I ordered is just what I was looking for. The people who helped me was great
by:
Parts fit perfectly, directions were very easy to understand.
by:
2019 Chevrolet Silverado 1500
Great product!
by:
Did not fit my truck 2026 Silverado 1500 4x4, website said it would fit, it does not fit, as axle plate is Square on my truck, this kit have round axle plate that interferes with spring shackle bolts, would not fit or even be centered. SO I am returning them, this needs to be corrected on your website, it does not fit the 2026 Silverado 1500 2x2 or 4x4!
Kate F. profile picture
Etrailer Expert

Kate F.

6/25/2026

I am very sorry to hear that these did not work for you John. I see on both the Pacbrake site and our site they are listed to not work with the Adaptive Ride Control, do you have that on your Silverado 1500? I am trying to get to the bottom of this so I can get the information corrected on both sites if needed.

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2005 Dodge Ram Pickup
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Info for this part was:

Employee Katherine B
Edited by:
Katherine B
Employee Alex H
Written by:
Alex H
Employee Andy C
Installed by:
Andy C

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