Hello all,

I currently own a 2017 F350 SRW gasser Lariet, and I’m looking to order an F450 b/c I’m possibly purchasing a 40’ Fifth wheel. Obviously STOck is extremely limited, but I found a dealer with a used 2020 XLT with 6k miles. I took it for a test drive and at 70MPH on the highway the rear of the truck vibrated so bad that the passenger seat was banging against the B pillar. The dealer tried to tell me this is normal because there was no weight on the rear axle. Around town it rode slightly harder than my 350 which seemed correct for the truck. Are the 450s really that bad on the highway with no weight in them?

 

Ford does put a vibration damper on the frame near the receiver hitch so the F450s are more prone to vibrations than the F350s. I think it has to do with the tires though. The 19.5" tires can be harder to get balanced, but they shouldn't be that bad. My 2017 is really smooth at 70mph empty with Conti Hybrid HD3s that should be on that 450 you test drove. I start picking up a little vibration at 80mph empty, but nothing as bad as you experienced. My Dad's 2008 450 with more aggressive Michelin tires gets the same level of vibration at 70mph that I get at 80mph, but he doesn't have any at 65mph. Zero vibration on either truck when they are loaded at speed. I would guess the one you drove needs the tires rebalanced.

 

I don't own an F-450 but do know that what the dealer told you, ".... this is normal because there was no weight on the rear axle." is absolutely BS.

 

That sounds crazy. I wouldn't buy that truck until it's corrected. Could be a few things...tire balance, failing tire (i.e. bulging), shocks, u-joint,, broken/loose suspension etc. May be an expensive reason a relatively new truck with few miles is up for sale.

 

yeah, that’s what I figured but I knew I’d get the real story here!….I love my 350, and IMO rides great…..I really wanted to see how much tighter the steering radius was on the 450 which is why I test drove it….I was really surprised by how bad it was on the highway. You could actually see the top of the pass seat banging off the B post! The side view mirrors were vibrating so much you couldn’t see through them! To me it felt way worse than just tires out of balance…..it almost felt like the whole rear end was shimmying back and forth. It’s probably why it was traded in with only 5k miles!

 

By the way the turning radius on that truck is unbelievable!!😎

 

A good friend of mine ended up trading his 2021 F450 for a GM due to the vibration. Killed him because he loved the F450 for towing. But no one could figure out the vibration on the highway. Ford replaced tires, road force balanced them, etc. He decided to buy a $6K set of aftermarket wheels and tires and it still shook. With the crazy market, he didn't have any issues selling. He made his $6K back and then some to an online buyer.

 

So I have a 2018 F450 and run a F450 group Facebook page.
What you describe can be common on some F450s and varies for each rig.
First step is set the tires pressure to the correctly ammount. Empty the 19.5 should be about 70psi in the rear and 80 in the front.
If they have 110 in them they will bounce around empty.
Next the taperd bead on the 19.5 tires can EASILY cause the tire to mount with the tire haveing considerable run out, so you need a tire installer that KNOWS what they are doing and willing to put in the time to mount them correctly.
Next, most are having the best luck with balance beads insted of fixed weight to balance the tires.
I have the internal beads on my 2018 F450 but other really like the centramatics or simular and NO fixed weights.
Some have alseitched to 20" or larger wheels with regular LT tires and happy with the results, snd dome to a different brand of 29.5 tires with good results.
Lastly, it might be a combination af the above and the road itself.
I recently got a bad vibration and was really concerned but it went away when the road surface changed and has not been back.
I know I bought an F450 necase I have a very HEAVY slide in csmper.
It is used as a daily drive at times too.
it is a HEAVY duty truck so it is not ment to be a smooth riding rig..
I stay below 70mph most of the time and get the best mpgs under 65mph.
I am very comfortable at those speeds so I have less trouble than those that need to go 70mph or more.
I have found over the years is no mater how fast I drive, I always get there when I get there.
good luck

 

Current owner of 2018 F450, never had vibration and been using Centramatic wheel balancers since 5k miles. I lean towards the wheel/tire combo not balanced correctly on that 2020. And that bad of a shake is not normal at all! Can't beat the turning radius and bigger brakes.

 

Some great info! Thanks!

 

Do all 4 of the rear wheels get centered on the hub, or only the inner pair? I've only had SRW trucks, but I recall reading about an aftermarket set of sleeves used to keep the dual rims centered with each other until a few of the lug nuts are tightened. After tightening a few of the nuts, the sleeves are removed in order to install the remaining lug nuts.

 

All my 450s do that.

500lbs of sand bags in the bed and Bilstein shocks and it goes away.


It's stiff springs. That's all.

The vibration comes from the springs hitting the top of the cycle. I'm not sure how to say it.

 

No 450's or any truck for that matter should ever do that. My 21 450 is dead steady at all speeds loaded or unloaded. I am in the 450 FB group noted above as well. Some of the owners in there have found bent driveshafts as well as bent/warped inner rear wheels. I would check those first. Adding wheel balances or whatever in my opinion is masking an issue that needs correcting. I've read long threads in there where guys threw piles of cash chasing a wheel balancing issue that didn't exist.

 

Thats good to hear! I’m going to try to test drive a new one before placing my order for a ‘22 just to make sure this is not the norm.

 

Yeah they have stiff springs and will bounce on a bouncy road but definitely shouldn't have seats hitting the pillar...at least not on a halfway decent road.