Install these microcellular urethane springs above your rear axle to stabilize and support your vehicle's existing suspension. Unlike many one-spring-fits-all kits on the market, this one can be customized according to the weight of your cargo. Lowest Prices for the best Vehicle Suspension from Firestone. Firestone Work-Rite Custom Helper Springs Kit - Rear Axle part number F8620 can be ordered online at or call 800-298-8924 for expert service.
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Vehicle Suspension > Rear Axle Suspension > Suspension Enhancement Kit > Jounce-Style Springs > Micro-cellular Urethane > Firestone

Firestone Work-Rite Custom Helper Springs Kit - Rear Axle

Firestone Vehicle Suspension

(13 reviews)

Code:   F8620



Custom Fit Product

Shipping Special

Shipping Weight: 11.71 pounds


Firestone Vehicle Suspension - F8620

Install these microcellular urethane springs above your rear axle to stabilize and support your vehicle's existing suspension. Unlike many one-spring-fits-all kits on the market, this one can be customized according to the weight of your cargo.


  • Improves suspension, handling and loaded ride comfort
    • Increases stability and minimizes sway from wind gusts or rough roads
    • Cuts down on road shock and provides a cushion to soften contact between axle and frame - helps to prevent bottoming out
    • Reduces suspension fatigue and spring sag
    • Does not affect your vehicle's ride when it has no load
  • Adjustable - offers spacers that allow you to customize for your typical load weight
    • Install more spacers to increase truck height and handle heavy loads; install fewer spacers for light loads
  • Made from injection-molded, microcellular urethane that has been engineered specifically for automotive applications
    • High resistance to repeated compression
      • Springs retain their shape longer
      • Less play is introduced into the suspension, giving you more control
    • Smooth axle-to-spring contact with urethane springs
    • Low temperature flexibility to -84 F (-63 C) helps springs work better in cold conditions
    • Effective resistance to road chemicals - extends life of springs
  • Requires no air-pressure monitoring as air springs do
  • Installs easily above your rear axle
    • No-drill design uses existing holes in the frame for installation in just 30 - 40 minutes
  • Saves money
    • Priced less than air suspension systems - enhanced support at lower cost
    • Protects your factory suspension from wear and tear - less maintenance required
  • Includes all parts needed for installation
    • 2 Load-assist springs
    • 1/2" Thick spacers for customizing support
    • Brackets and mounting hardware
  • Designed to work with a suspension system that is in good working order
  • Made in USA
  • 2 Year warranty on springs

Note: Firestone Work-Rite springs will not increase your vehicle's weight-carrying capacity. Do not exceed the manufacturer's weight limit for your vehicle.

Work-Rite springs reduce the rear sagging that accompanies heavy loads or that results from towing hefty trailers. Hauling heavy cargo or pulling a trailer often causes the rear of your vehicle to sag while the front end rises. This means that the rear axle is handling the full weight of the load and more of your truck's weight as well. The lighter weight on the front axle means that the front tires make less contact with the road, causing problems with traction, steering and braking. With the springs helping to more evenly distribute the weight, your tires make better contact with the road and your driving control improves greatly.

One size does not fit all when it comes to the load you carry. This spring kit lets you choose from different spacer combinations during installation to give you customized load support for the weight of the cargo that you typically haul. Using the optional spacers, you can adjust the distance between your springs and axle. Closing the gap between the springs and your axle offers more immediate support and better maneuverability because the Work-Rite springs respond sooner to the load's weight than springs without spacers.

Diagram showing how much space to leave between WorkRite springs and axleDiagram showing how much space to leave between WorkRite springs and axle

Use more spacers to close the gap if you usually haul heavy loads, engaging the Work-Rite springs sooner and increasing the height and improving the handling of your vehicle when it's loaded. Use fewer spacers if your loads are light or if you frequently travel unloaded. Leaving at least a 1/4-inch gap between the springs and your axle allows the existing leaf springs to operate normally when you're unloaded, ensuring a smooth, comfortable ride.

Each helper spring in the kit works independently to support the passenger's or driver's side of your truck so that when you swerve or turn sharply, the spring compensates to reduce body roll. Because your vehicle handles better with the springs, less turbulence is passed along to the trailer, helping to keep the trailer in line.

Your driving comfort is further enhanced if the trailer does begin to sway (for example, from a gust of wind or a passing big rig) because the movement from the trailer is not transferred to your vehicle. The helper springs also work to make the sway subside more quickly.

Work-Rite Springs Versus the Competition

Work-Rite springs are made of a special polymer that helps them to retain their shape better than rubber and still work in below-freezing conditions. They are less elastic than rubber, meaning less play is introduced into the suspension than with rubber springs. The firmer Work-Rite springs also resist road chemicals and extreme temperatures better than rubber, so they last longer.

F8620 Firestone Work Right Helper Springs Kit - Rear Axle

Video of Firestone Work-Rite Custom Helper Springs Kit - Rear Axle

Videos are provided as a guide only. Refer to manufacturer
installation instructions and specs for complete information.

Video Firestone Load Assist Install 2009 Dodge Ram 1500
Firestone Work-Rite Load Assist Installation - 2009 Dodge Ram 1500

Video Transcript for Firestone Work-Rite Load Assist Installation - 2009 Dodge Ram 1500

Today on this 2009 Dodge Ram 1500 we are going to install part number F8620 from Firestone. This is their Work-Rite Load Assist. To give you an idea of what is going on the new Firestone part actually replaces the factory bump stop right here. When you have the truck fully loaded, the only way it is going to stop is when it hits this bump stop and goes down to the axle. You can see we have got quite a bit of difference so if we put a load in the back of the truck or bounce up and down the road you can see how much travel this has. 00:28

With the new part installed it will take up that extra space and the vehicle will not sag as much on your load. The first step involved is to get the truck in the air we are going to use a standard jack stand to hold everything up. And we need to remove the rear tire. This is the factory bump stop right here, a better view of it. Basically we just have to remove it. You can pry it out or some cases maybe you can pull it out on your own. The truck is already prepped, lets go back to the kit and do some preassembly there. We have the parts assembled here for one side of the system. 01:06

We will cover the parts real quick. Obviously this is the new spring constructed of polyurethane material and then we have the brackets that hold everything together. You have this round plate which fits on top of the spring and then you have this ring that sits on top of that and then you have these two pieces that clamp over the existing bump stop on the vehicle so when you bolt it all together it clamps everything together. A couple of options, when you set it up you have a choice of using a couple of different spacers. Basically what this does is allows you to adjust the spring up and down. Say for instance the carpeting right here is the bump stop on the truck. You want to leave about 1/ 4 inch of space in between the two so it will give you a lot of space in here. You can lower it to take up the gap. Also if you want the springs to work sooner like in the truck you use in a constant loaded condition you probably want to add the spacers to have it already working right off the bat. 02:00

You get two different sized spacers to do that with. If by chance you did want to add spacers later which you can, undo the bolts, take it apart, add the spacers, reassemble, and then reinstall on the truck. Start with the spring. Since we are not going to use the spacers we are going to use the short bolt. If we did we would use this long bolt. Take the short bolt and the flat washer and install it where it comes out the end right here. It is a good idea to use a socket and extension and install the plate. You can see how the bolt holes are sunk in, that is because the bolts get installed like this so you want to have the plate mounted like this where the studs are pointing up. We will add our lock nut to it and just simply tighten it down at this point. Torque these down as specified in the instructions. We will do some more preassembly. Put the ring, center it to keep it from moving around and then take the clamp and do one side and run the bolt through and loosely install the flange nut. Take the middle one and run it down about half way so we still have some flexible room but it will hold it in place while I deal with the other side. 03:20

Lets go over to the truck and start assembling. We will slip it into place. As you can see here the clamp will fit over the edge and that will help hold everything in place while we install the other side. You can see how it is working on there right now so just snug down the bolts. Once you have everything snugged down go all the way around evenly and tighten them up as specified in the instructions. We have got our work rite installed so lets reinstall the back wheel and see what we have got. Once you have it installed you want to double check to make sure you have about 1/ 4 inch of space in between and not much more than that. If it is barely touching it will be fine also. Again if you need to adjust the height you can use the spacers in between the spring and the plate. Now we have got everything reassembled. You want to take it for a test run unloaded like it is now and then you may want to take a test run with it fully loaded. You may want to add a spacer or a spacer depending on how you originally installed it. There you have it for part number F8620 from Firestone.

This Product Fits The Following Vehicles

2012 - 2012 Dodge CV

2012 - 2012 Ram CV

2009 - 2013 Dodge Ram Pickup 1500, Crew and Quad Cab

2009 - 2013 Dodge Ram Pickup 1500, Regular Cab

2010 - 2013 Ram 1500 Crew and Quad Cab

2010 - 2013 Ram 1500 Regular Cab

Replacement parts available for this product

Customer Reviews

Firestone Work-Rite Custom Helper Springs Kit - Rear Axle - F8620

Average Customer Rating:  4.5 out of 5 stars   (13 Customer Reviews)

Install these microcellular urethane springs above your rear axle to stabilize and support your vehicle's existing suspension. Unlike many one-spring-fits-all kits on the market, this one can be customized according to the weight of your cargo.

- F8620

by: Tom K.08/30/2012

The product was exactly what I expected and was delivered in just 2 days......Great Service! 53563

- F8620

by: anthony03/05/2013

shipping was fast and instlation was a snap 68986

- F8620

by: WADE WILLSON11/29/2012

So simple I dont see any problems. Thank You 60268

- F8627

by: Dave S.09/28/2013

Review from a similar Firestone Work-Rite Rear Helper Springs

I was very pleasantly surprised at how quickly my order was filled and delivered. I got timely responses letting me know the status of my order and how to track it. It was actually delivered before I could track it! The installation was very simple, and everything fit as it was illustrated. Unfortunately, with over 260,000 miles on my Chrysler Town and Country, the springs have lost their arch enough that there is no space between the helper springs and the axle, even when unloaded. Even so, the ride is not harsh, and my wife commented that the car feels more stable. I am pleased that I can now carry extra passengers and/or cargo without feeling the rear axle hit the bumper pads. Thank you, etrailer!! 101847

- F8605

by: Danny02/07/2013

Review from a similar Firestone Work-Rite Rear Helper Springs

Very Easy install but a little longer than advertised, just two bolts 65353

- F8605

by: Dave T05/27/2013

Review from a similar Firestone Work-Rite Rear Helper Springs

Great product. Fast shipping and all that. Truck springs sagged 2.5 in. before and now only 1in. pulling travel trailer and I didnt get the front to back sway Id had before. This was my first trip out with the spring assist so havent really experienced every situation but so far Im pleased. Absolutely no difference unloaded and I glad about that too. Very easy to install, no problems at all, took about 30 to 40 minutes. 82071

- F8607

by: Dick B.09/13/2012

Review from a similar Firestone Work-Rite Rear Helper Springs

Excellent product for what I needed (raise the bed level when towing a 5th wheel) that works just fine and easy to install. However, be aware that this will not work well for off-road or washboard gravel roads, as it make the rear axle springs very stiff and jittery. But work great on pavement and city streets. 54591

- F8626

by: HUMPREY01/15/2013

Review from a similar Firestone Work-Rite Rear Helper Springs

Etrailer: Fast shipping!!! The product does its purpose. I have a cargo box attached to the hitch, with another on my roof, 2 dogs in the back, and to adults, and NO SAG. 63154

- F8605

by: samuel lee07/10/2012

Review from a similar Firestone Work-Rite Rear Helper Springs

I would like to thank all for the excellent job and service . Ia'm going to order more from etrailer and till my friends .Thanks to all. 47431

- F8615

by: John01/09/2015

Review from a similar Firestone Work-Rite Rear Helper Springs

I have just received the product and plan on installing after work today. The team at etrailer did a great job!!! 168358

- F8605

by: Larry Crosby08/18/2014

Review from a similar Firestone Work-Rite Rear Helper Springs

Product worked just as advertised. Made pulling a trailer much safer and with less sway. 147288

- F8611

ratingratingratingratingrating by: Mark K11/04/2014

Review from a similar Firestone Work-Rite Rear Helper Springs

Installed easily but only lasted 4 days and 1 campout. Wouldn't recommend. 159206

- F8627

by: DG12/20/2013

Review from a similar Firestone Work-Rite Rear Helper Springs

Quick fulfillment, exactly what I order ed. 110675


Ask the Experts about this Firestone Vehicle Suspension
Do you have a question about this Vehicle Suspension?

  • Will the Timbren Rear Suspension Enhancement System Affect the Empty Ride on a 2011 Dodge Ram 1500
  • You are in luck, I actually have a 2009 Dodge Ram 1500 pickup. I am very happy with the unloaded ride as well, but when it came to towing a trailer I was disappointed. I added a rubber spring enhancement system, Firestone Work Rite, item # F8620, to the truck and towing a loaded trailer is much nicer and the ride is significantly better. That is my truck in the installation video. The Firestone # F8620 system will work on the 2009 to 2011 Dodge trucks. The Timbren system you mentioned,...
    view full answer...

  • Will Firestone Work-Rite Helper Springs Reduce Sag on a Chevy Silverado 2500HD Diesel
  • The Firestone Woirk-Rite springs will help with the sag at the back of your truck. However, # F8620, is designed for Dodge vehicles and will not fit your Silverado. I would need to know the year of your truck and if it is 4-wheel drive or 2-wheel drive to make a recommendation. Air bags should not cause any sway issues. However air bags would not be my first choice for this application since they are better for leveling a bed side to side for trucks that carry varying load sizes and...
    view full answer...

  • Comparing Firestone Work-Rite and Timbren Suspension Enhancement Springs for 2014 GMC Sierra 1500
  • I use the Timbren suspension enhancement springs on my truck and I love them. After testing the Timbren springs with the Firestone Work-Rite springs, we found that the Timbrens have a slight edge when it comes to reducing sag, but the Work-Rite springs provide a more comfortable ride when you are not towing or carrying a heavy load. When my truck bed is empty, I can feel the Timbren springs from time to time over bumps or uneven roads. Both springs serve the same purpose and would be excellent...
    view full answer...

  • Suspension Enhancement Recommendation for a 2012 Ram 1500 Towing Fifth Wheel Trailer
  • Either suspension enhancement like a Timbren or an air bag system would work great for your 2012 Ram 1500 to help it tow level. Personally I like the Firestone Work-Rite Custom Helper Springs Kit # F8620 these will provide you with additional suspension support when you are towing and won't affect your ride quality when unloaded. The Timbrens are similar to this setup, but have a much harsher ride. A coworker of mine here has basically your exact truck and has had the Timbrens and...
    view full answer...

Do you have a question about this Vehicle Suspension?

Info for this part was:

Written by:
Tyler C

Expert Research:
Michael H

Written by:
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Expert Research:
John H

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