2001 F150 4x4 harsh shaking. When driving at consistent speeds the truck begins to shutter and shake, begins as a light shake and becomes extremely harsh fast. This is not like a vibration that can be felt, but a really harsh shaking of the entire truck.

The truck continues to shake after taking foot off gas and braking. It will shake harshly even when braking and slowed down to 5mph, but instantly goes away once at a complete stop. Accelerate immediately after coming to a complete stop and it completely goes away and drives normal for a day.

Check Engine light has not come on.

Tachometer stays consistent RPM.

Shift into neutral does not stop shaking. Only coming to a complete stop ether in drive or neutral does the shaking stop.

It happens driving at consistent speeds going 35mph & 65mph, etc.

Any thoughts on what the issue could be?

Thanks for your time and thoughts!

 

Drive shaft joints likely are dry and/or worn out.
Get under and check it out.
Good luck.

 

it may not just be your drive shaft, my truck is doing the same thing, i have an '02 150 ext cab fx4, i was driving down the road one day when something thumped under my hood and my truck started to shake, a little with acceleration and a lot with constant speeds but also stops at an idled, shakes in nuetral as well, the issue with mine upon deep inspection was that she had spit out the spark plug off of one of her cylinders, causing it to misfire and shake the truck, also leaves the strong smell of exhaust as it now blows right out for the cylinder, yours may not have spit the plug yet but they may very well be working themselves loose, i know replacement plug and wire assemblies can be purchased through autozone for about 56 bucks, another possiblity might be a blown head gasket or exhaust manifold. all things to check for, just suggestions from experience, if however it iis your spark plugs coming off the cylinders, the tell tale noise that i heard but ignored thinking nothing of it is a slight whispered thump that keeps time with the firing order of your cylinders. so my advice, is start your truck, pop the hood and feel for any exhaust leaks and reall6y listen to the sound of the engine while you drive it.

 

Coils going bad also will cause a shake that is very violent!

I have had that happen more than once. I keep spare ones at home. It is common and it sounds like what you are describing. There are many threads about it and bluegrass does a great job explaining it.

 

vibration from missfire (coil) should go away as soon as you take your foot of the gas. Normally not heavy vibration at constant speed, but more vibration as you accelerate.

 

besides the driveshaft, jack up each tire and rotate by hand and look for runout and bulges.