I'd noticed this on my 04 Lariat now and again at lower speeds around town from the time the truck was new 2.5 years ago: Certain types of road bumps would cause the truck to move slightly sideways. It never bothered me much, I attributed it to something about the live axle, since I'm more accustomed to independent suspension on smaller cars. Well, last week I drove it to NY City and back, a total of almost 5k miles, so out in the east I found some SERIOUS bumps in the road. A couple of times hitting bumps the truck moved so far sideways it tightened my sphincter up I can tell ya! My question is, is this normal for this truck? Mine now has 36k miles. Could this be worn shocks? Thanks for replies.

 

when you hit a bump and were at some speed, I'd say it's normal. It's just that the back end is so light for the stiff springs, it's easier for it to simply bounce up in the air than for the springs to compress a lot.

We have a spot up here on an interstate with a nice curve and a big bump at a concrete joint, if I hit it just right the back end hops up and she goes slightly sideways. Scares the crap out of the person behind me!

 

I think all trucks do this to some degree

 

If you're not really pressed for money, I'd invest into some Bilsteins and call it a day. Im sure you'll be glad you spent the money!!

 

OOPS! Double post....apologies.

 

If you are running your tire pressures on the high side, it could cause this.

 

it is the shocks...I have run LT 265 70 17 bfg TA tires at 65 PSI and it doubles side ways hop ten fold, The only advantage to the out board rear shocks is cornoring, the old 04 F-150 can cornor like it is on rails as long as thiers no bumps in the road, but for hauling or general ride ability, the out board shocks fail to impress me, my new 06 2500 reg cab 4x4 ram has a way better ride and less hoppy hop but I'm finding I have to adress my driving style due to the big Ram likes to plow stright a head in the cornor's, were as the Ford could make the curves..

 

Thanks for the replies and info. I kinda thought it was normal. I hit a bump at a point where road transitioned onto overpass, going slightly downhill, perhaps in a very gentle right curve (can't recall exactly) and I'm telling you my heart was really pounding for about five minutes after that. My gf nearly peed. It happened once more, and both times were in rain. I'm going to start looking at new shocks. I've always run 40 psi in the tires, but I set them at home where the elevation is 5500 feet. This trip was to near sea level, so I reckon effective pressure was a fair amount less than 40 lbs, since I never checked or adjusted it during the trip. It occurred to me that a truck like this is set up to carry a load and handle pretty much good, but to run the bed empty or with a light load, like I was, puts the truck outside its natural environment...

 

If you're running 40 PSI in your tires that's a big part of your problem. Your sidewalls can't flex as much to absorb the bumps. I'll bet that if you lower your tire pressure down to the recommended pressure it will help quite a bit.

FYI: The difference in air pressure between 5500 feet and sea level is less than 3 PSIG.

Grim

 

If he has the LT tires rather than the P series tires, 40 is the correct pressure.

 

My 05 Supercrew 4x4 did this since New also, I am at 12,500 Miles.
I put a Leer topper on it last week, Rides Better Now with the Weight on the Back end. KR Paul

 

I have this very bad, and it's a broken rack housing. Look under your truck for your steering rack, it's easy to find but you'll have to get under there to see. Here is a video of what to look for, the one user who viewed my thread went out and noticed his was exactly the same. It's obviously a weakspot where two metals meet on the housing. Supposedly his alignment shop never caught that either, maybe there are more out there (I know there is if the one guy who checked, had the same problem). If you have this problem your truck might pull to one side, one of your tires shimmy's when taking a turn, etc.

 

I had it happening on my truck stock and lifted and on my last Silverado it happened as well. Sometimes worse than others.

 

SHOCKS! I had the same problem with my unlifted truck. I took an offramp at speed hit the point where the assphault ends and the concrete bridge portion starts my truck kicked out and a little poop fell out of my butt. It was scary! I lifted my truck and put some adjustable MX6 shocks in the rear and WHAMO no more kick out!

 

Thanks, I try and learn something new everyday.

When I initially test drove my truck at the dealer, it had a lower-profile tire with 20" rims. I had the rims taken off and replaced with Lariat wheels and tires. It really improved the ride on my truck and the shocks were brand new.

Grim