I just picked up an 03 F250 6.8L Supercab. I had test driven 4 other F250 before this one with varying ride quality. A couple of them seemed to ride really well. One with a lift kit was very bouncy. One rode pretty crappy. Mind seems great on nice smooth roads but anything over very minor bumps is rattling the whole truck. I'm wondering if this is fairly normal for a truck with E load rating 10 ply tires on it or maybe it's possible I need new shocks or is just the nature of the (super duty) beast? Anything thoughts on how best to test for worn shocks? Also, the truck does have a rear air bag system but since I feel it on bumps in the front as well I'm not sure adjusting the air will do much but I am willing to try. Plus, when it's time for new tires would going to standard P metric tire instead of LT tires affect my towing or payload much? I don't expect to be hauling more than about 1000lbs with the possibilty of another 8000 in tow (this is really a worst case scenario).

Thanks for any help or suggestions.

 

D rated tires with lower pressures will do wonders. You don't want to go to P rated tires, way too light. Good shocks like bilstiens do wonders for ride too. The "bouncy lifted" truck you drove would ride great with good shocks. Most duties don't flex enough to bounce and that is a good quality that shocks can fix. That's why F150 ride nice.

 

Which Bilstein's would you recommend? 4600 series or 5100 series off road or something else? I do not plan to do any off-roading. Just looking for the best ride I can get without compromising on my towing and payload too much. As I mentioned. I don't think what I'll be towing/hauling will max out the truck since I've seen plenty of people doing the same as I plan to with F150's and the like.

 

Also, when I look up my tire size, 265/75-16 I'm not seeing any D load rated tires. Is there an optional size that will still fit the stock wheels?

Scratch that, I found some. For some reason the Tire Rack search wasn't letting go of my truck. After refreshing and searching by tire size it worked.

 

You don't need "D" rated tires to lower the pressure.

Attached is a load inflation table. Get your truck weighed on a truck scale to determine your axle weights. Then, using the attached table, determine an appropriate pressure from there. Make sure you give yourself room for anything you may be hauling, and remember to increase pressures as the load requires.

 

That's some good information. Maybe too much. I'm having a little trouble figuring how I'd convert my actual truck weight to the correct inflation pressure. The guide does a good job explaining how to figure out using different tire sizes but I don't plan to change tire sizes.

My sticker shows using E load range tires inflated at 55psi front and 70psi rear. The chart shows 2625 at 55psi and 3105 at 70psi.

My sticker also shows GVWR at 8800lbs. Front GAWR is 4800lbs. Rear GAWR is 6084lbs. Does that help at all?


Where does one go to get their truck weighed?

 

Many truck stops have certified scales you can weigh your truck on. Costs about $10 for most of them, and I think it's well worth it.

Take your GAWRs as a conservative number to use for pressures. This is the maximum rated load for each axle with your factory suspension, that is the heaviest they are ever supposed to be. Divide them by two, and you have your max individual tire load.

So...4,800/2 = 2,300 lbs. Find the pressure that supports 2,300 lbs, and you have a safe number to inflate to for the fronts. Do the same for the rears. I suspect it will be very close to the number on your door sticker.

Empty your truck should only be around 3,200 lbs on the rear axle. If you're not putting 3,000 lbs in the bed, you don't need air pressure to support that much. So airing down to a pressure that, say, supports 2,000 lbs per tire would be safe for an unloaded ride. Just make sure to air up before you load up!

 

I was wondering about that. I'll give one a call today and try to get out there.

Quote:

Originally Posted by Tom

Just make sure to air up before you load up!

This should be a warning label or something .

Thanks again.

I need to figure out the airbag setup they put on the rear as well.

 

I run 285/75R-16 tires on my 02. It is a diesel, so the front is heavier than yours. Stock wheels, stock height. I run 70psi in the front and 45psi in the rears. I air up the rears if I'm going to be towing or hauling anything. They are E-rated tires too. I rotate them regularly and get even tire wear. I found this, along with good shocks to get the best ride possible. It ain't a Lincoln, so don't expect too much!

 

The air pressure is good advice.

I have had good luck with just the basic Monroe yellow shocks on my F250. I have them now and I love them. I put Rancho 9000s on my last truck because it rode like the axles were welded to the frame. Those shocks did not help the situation.

One thing that affects ride quality in a leaf sprung vehicle is the friction between each individual leaf in the spring pack. They have to be able to slide on one another to get a nice smooth ride. As a result, companies sell a graphite based spring paint to help smooth things out. They also use teflon slider pads in between to aid in this. Doing this will take some time and effort though.

If you are actually looking to do some suspension modding, this 2" lift from Old Man Emu is supposed to be fantastic in improving ride quality. It is on my bucket list.

2001 Ford F-250 Super Duty Height Increase - 4-Wheel & Off-Road Magazine

Old Man Emu 2.25" Suspension Lift for 1999-2004 Ford F350 Superduty

 

Great community providing more great info.

I definitely don't expect it to ride like a Lincoln but would like to quiet down the rattling over bumps somewhat. If airing down and new shocks will help, that's the road I'll go first. The shocks do look like they've been on a while. I'll start with airing down and then look at swapping shocks when I'm done moving (in the middle of getting my house on the market). I won't be doing any kind of lift or bigger tires. I'm only putting money in the truck as absolutely necessary or really make sense (spray in bed liner, tonneau). I won't even consider new tires until necessary either. The Transforce AT's on it now should carry me through another year I suspect.

 

That made me think of one other thing regarding rattles... if you hear a sound over bumps that sounds like a thumping or banging almost under your feet, that is the front swaybar. It is time to replace the bushings in it. That is a very common noise in these trucks.

On the Transforce ATs... I had them on my truck when I bought it. They are a FANTASTIC highway tire! They are smooth, planted, and quiet. They had 80 psi in them when I bought the truck and I just left them as is. Never had to add air or anything. I probably could have softened the truck up a bit, but I was getting 14-16 mpg on the highway with them so I let them be. My only complaint is they scared the **** out of me in snow and ice. I was driving a 7200lb sled with these tires.... granted that is not what they are designed for.

They still had some tread on them when I replaced them with General Grabber AT2s, so I sold them. The Grabbers are not as smoother, definitely a bit louder, and don't feel quite as planted at highway speed, but they do better suit my use for the truck. I run the Grabbers at 60 psi as they have a noticeably stiffer side wall. I have considered lowering the pressure some, but haven't yet.

This is just something to keep in mind depending on where you live and what kind of use your truck will see

 

Look on your Door Label. Do NOT use any tire with less than an E rating, even if your plans don't include towing or carrying extra weight.
Your truck is designed and built for E rated Tires. You don't need to run Max pressure in every day driving. Max pressure is for weight carrying purposes. Running Max pressure in your daily driving not only makes your ride harder it will wear your tires uneven. Actually its illegal to install any tire with a lesser ability than your door sticker states.
If you want a smoother ride, buy an F150.
If anyone wants to dispute this RUN.

 

Yeah, I'll stick with the E load rated tires and air them down. Still thinking new shocks may be due in the near future. I don't expect luxury vehicle ride but when comparing to others I've driven it seems it could be somewhat better.

 

Please cite some documentation for that statement.