Jounce Bumper Spring versus Air Springs on a lifted 2008 Ford F-250

Question:

I have a lifted 4.5 2008 F-250 that tows a toy hauler 5th wheel, and Im looking for something to help take the load off of the suspension a bit, due to the hitch and pin weight when hooked up. I have a Reese 20k sliding 5th wheel hitch currently and have been looking into an airbag system but found the jounce systems. I know the air bags give a little more flexibility than the jounce systems, and will need adjusting based on the load. I dont haul much besides the 5th wheel, but Im still on the fence about which system to go with, and which would be the best for the lifted suspension. I could not find any measurements for height on the jounce systems, but I do see that some of them have spacers which can be added. Can you guys shed any light on any of this for me or point me in the right direction? Thanks!

asked by: Matt K

Expert Reply:

For your 2008 Ford F-250, I can help you with enhancing your factory suspension. You are correct in saying that the air bags have more flexibility, but do require more maintenance than the jounce spring systems which are maintenance free. Either option will work with your lifted truck, but if you are primarily concerned about suspension support when towing your 5th wheel, then the jounce replacement springs are an excellent low cost option.

For your needs, I'd suggest the Timbren Rear Suspension Enhancement System, # TFR250SDF. I contacted the manufacturer and asked them about a 4-1/2 lift on your specific truck and this was their recommendation. They said you will want to measure your truck from frame to axle when unloaded to determine the number of spacers you'll need for your lift. The 1" Spacer is # A25723-90AH00 and the 1/2" Spacer is # TA25722-90P00.

Here is how you determine what you need. You take the measurement from the frame to the axle when unloaded as mentioned, then you subtract the bracket, the spring, and the spacer in this kit (7-3/4"). Then the recommended clearance once installed is between 1/2" and 1" between the rubber spring and the axle, so you also want to subtract that. So, take the frame to axle measurement at subtract 8-1/4 inches on the low end or 8-3/4 inches on the high end. The remaining number will tell you what spacer or spacers you need.

If you choose to go the airbag route for added comfort and the more adjustable to each need option, then I would recommend the Air Lift LoadLifter 5000 Ultimate Air Helper Springs with Internal Jounce Bumpers, # AL88397. This system is a fit for your truck and will give you the diverse functionality of air springs, but unique to this system is an internal jounce bumper so it will engage if you have insufficient or zero air pressure under a heavy load. This particular system gives you the benefit of both systems.

Due to the lift on your vehicle, with the airbags, I'd suggest using a spacer like # AL52440. I've included a video to this spacer installation. Each spacer adds 1 inch.

To ensure that the airlines are cut straight to prevent leaks, I'd also suggest using this Air Lift Air Hose Cutter, # AL10530.