Vibration on all 4 tires

Why does my truck vibrate on all 4 wheels when I go over come rough road? Doesn’t happen every time. When it does do it at 65 mph or more, the truck vibrates on all 4’s side to side until speed coasts to around 60mph or less. Can’t hit the brakes cuz I think (I know) I’d flip. I can guide it by just hanging on to the steering wheel (feels like ‘for dear life’) until it comes out of it. I’ve had the tires spun balanced, rotated, aligned, & rt frt tie rod replaced. Thought that would do it, but no dice. Extremely scary. And, I can never set the cruise for fear it will happen (again) with it on. It happened twice when it was set. It was all I could do to turn it off while it was surging forward and vibrating the entire truck. Wondering if you have any thoughts or what should be checked?

Get shocks, ball joints, bushings, steering gear checked.

And stay below 65 mph. Seriously, you could cause a crash.

How do you know all four wheels are vibrating?

Many trucks have a steering damper to prvent this problem. Try replacing it if you have one.

How “rough” a road?

I wholeheartedly agree that the chassis needs to be checked out thoroughly, but if you’'re cruising over a washboard road at 65++ in an F250 then you’d better expect everything to vibrate. And you’d better expect the truck to float around and not feel in control…the tires are bouncing off the bumps and floating in the air. These suspensions are FIRM, and made to carry loads at teh expense of a comfy ride.

Thanks, shocks were checked but not all the other. I will have these checked out.

Thanks, I will have this and the other suggestions looked at.

Thanks, but it really isn’t a washboard. Sometimes it is a small dip where a bridge deck or overpass deck meets up with the pavement on either side of it on interstate. The other areas are not that bad but maybe a blacktop repair in the road that isn’t as smooth as it should be. Your right about the stiff suspension and the firm, less comfy ride and I understand what you are referring to. However, I have had this suspension in all of my trucks and never experienced “this” type of problem. It seems to not be the “normal” floating and bouncing that you can get from a superduty. It is definitely different.

You – or someone brawnier if you are too small – should probably walk around the truck and grab each tire at the top and shake it in and out. Then repeat grabbing the tire at 3 and 9 O’clock and twisting. If anything feels loose or there are inappropriate noises, get a mechanic to look at it. That procedure won’t catch all suspension/steering problems but it will find a lot including some things you’d want fixed before you drove anywhere at speed.

It could possibly be a tire also although it doesn’t sound especially like a tire problem. Invest a couple of bucks in a tire pressure gauge and check the tire pressures. There will probably be a sticker on one of the door posts that will tell you the recommended pressure(s). If you run out of other ideas maybe swap the tires around and see if the problem goes away or changes.

This sounds like a shock problem - and the only way to test to see if a shock is good is with a shock dyno - very few people have those! Shocks can fail both “soft” and “hard” - and it sounds like yours have failed “hard”.

So changing shocks seems to be in order - but if you don’t want to do that, then slow down.

One other thought: perhaps it just does not have good tires. I once put a set of four Continentals on my pickup and they simply would not ride smooth, no matter what I tried. I (and my daughter) had that truck for a total of over 17 years and 338,000 miles and that set of Contis was the only time I ever had a ride problem.