TLB4

No to all of this. Coil overs don't increase payload. You're still putting the same amount of weight on the rear axle and frame. The only thing you're doing, is putting more weight on your shock mounts, and less on your leaf springs, which isn't really a great thing. Shocks are meant to create a smoother ride by absorbing the instant compression and release of your leaf springs. Not to take on the whole load of you leafsprings. And a load of wood isn't comparable to a 8,000 pound trailer. Totally different loads and weight distribution. You really should be looking into airbags.

Same for the OP, look into these airbags, they're exactly what you need.
http://www.autoanything.com/suspensi...A4899A0A0.aspx

Check you shackle mounts too if you're hauling this big of a trailer. The rear shackle mounts like to rust and snap off at the back of the leaf springs. Just something to be aware of.

kmpconley

I do agree that shocks absorb the initial impact from the road, but how do all of the components not work in conjunction with one another? Yes I understand that a load of wood is different than an 8000lb trailer, and I agree that airbags would also help with this, but to say beefing up his shocks wouldn't help seems to be an absurd statement. Hauling a 8000lb trailer I would think would pull his frame closer to the ground making it more susceptible to a rougher ride, and decreased handling while towing. I personally have noticed an increase in handling while towing, as well as a smoother ride. I'm not hauling 8000lbs, it's actually about half of that, but I haul a single axle 14ft trailer with 3 ATVs and camping equipment with a 4.2L V-6 (approximate weight with 2 Honda Rancher 4x4s, Honda Recon, and Misc equipment including the trailer is about 4600lbs). However, since upgrading my shocks, I've had better performance while steering and less drag down from a trailer. I've also noticed better braking. As far as the shackles go, I agree that you should prolly check these out. I had a 92 F-150 300 I6, and the Driverside shackle had rusted out. The back part of the leaf spring about rubbed a hole in my bed before I noticed it. So yes, def check those and make sure they are intact, and still in good shape cuz that would cause your bed to sag lower. With all that being said, I respectfully disagree with the other 2 gentlemen who commented. Upgrading your shocks may not be the complete fix to you problem, but the laws of physics suggest that it would help. I can see where they think it would cause a lot more stress on the shock mounts on the axle, however I've had these shocks on my truck since about 60-70k miles, I now have 260k miles on my truck, and have towed that trailer with ATVs 50+ times and have never noticed anything other than an increase in handling and smoother ride while towing. My first 60-70k miles I prolly towed that trailer 10-15 times, so enough I can give an honest comparison. To further add, u should check what your vehicle towing capacity is. I can tow 8000lbs with that V-6 but I would NEVER push it that far because it would be brutal on my motor and tranny. A 4.6 or 5.4 wouldn't be that bad on, but If you are towing a heavy load and don't believe ur truck can handle it, maybe a F-250 might be a better way to go.

cwjohnston

No, the truck handles the trailer just fine. Again, I'm not trying to increase capacity, but beef up the truck to increase its longevity, because hauling - even within capacity - increases wear and tear on the truck. I'm just trying to make the thing last a longer time. If anything, I'd trade the trailer in on a smaller one, because the darn thing's too big anyway. It's not even half full.

I may have not been clear on what I'm looking for, so sorry about that. But I'm not trying to increase the towing capacity of the truck. Instead, I'm thinking there must be upgraded components out there - such as shocks or springs or leafs, etc - that maybe I'll need to replace anyway (because the truck is 12 years old) and if I'm going to replace, maybe the upgraded components will handle the loads better, not let the truck handle bigger loads. Does that make any sense at all??
Thanks!

Feathermerchant

Many people replace their leaf springs after 12 or more years of use. When you do that you have the choice of spring rate (the number of inches of deflections vs the pounds of weight added). A higher spring rate will give you a stiffer ride when unloaded but less sag (deflection) when loaded.
FWIW I added a pair of 5000lb Air Lift bags to my 95 Dodge because the rear was too soft. I could air them down when not towing and with about 30psi in them it rode like a 3/4 ton.

MadMikeyL

Shocks aren't going to help with the sagging rear. Airbags are a good option since you can air them down when not towing. If you are towing a lot with it, you may want to consider having another leaf added to the rear springs. There is also another option which sounds a little counter-intuitive, but I'll tell you my experience relating to this. I also have a 2wd f150 that I do some towing with. The first few times towing heavy weights, it had the same issue, and while I wasn't I danger of bottoming out the suspension, it got a little sketchy at speed because of the nose of the truck sitting higher than the rear. I then lowered the truck with some 2" longer shackle bars in the rear and cut one coil off the front. After doing that, and then a new ball hitch to raise the ball back up the 2" that I lowered the rear, and now truck has a little rake to it when empty, and now when loaded up with a heavy trailer, it sits level, and it tows much better. So basically the options are airbags, stiffer rear springs, or slightly lower the truck.

norcal screw

Get a load distribution set up. It will solve your problem and make it more stable while towing. Any decent trailer joint will have them.