I have a 2000 Ford F-250 4x4 with 290,000 miles on it. It was given to me by my dad he used it to pull his travel trailer all over the United States and then it sat for a lil over a year. I got in it and it cranked right up I drove it back home about 80 miles and had no problems until one day i was driving at about 65 and tried to accelerate around someone automatically started shaking and every time I would push the throttle in it would decelerate I stopped on the side of the road for a minute then put it in drive got it back up to about 40 to 45 and started shaking again. Now every time I drive it it runs perfect until I get it to 40,45 mph then starts shaking hard again I have changed tranny fluid and filter my next step was to pull a torque converter from a similar year make and model and see if that fixes it plz let me know if there is any other things to check before dropping tranny

 

Hold on there, let's start with the basics , how's your fuel pressure? Have you changed your fuel filter? How's your oil level? Don't use any additives in the oil like Lucas, our engines hate that stuff. Do you have access to a compatible scanner that reads codes in your truck? (local auto parts store can't read codes in our trucks) gives a bit more so we can help.

 

Honestly I have just started to dive into the mechanical aspect of vehicles I keep my oil level where it needs to be and my dad added Lucas with every fill up cuz he ran red in it I have not check fuel filter or pressure and I have no scanner

 

If it is an automatic -- What happens when you turn off over-drive off when you are in the MPH range?

 

Dang, sounds exactly like what happened to old green yesterday.

Was almost certain it was a tire, but the shaking was erratic and sometimes it felt like a u-joint while other times it felt like something in the engine.

Took it to a friend's shop and we look it over. A front had developed a giant ball from one day to the next.

Limped it down to discount, spent $$$$$ on a new set of 4, and everything is good now.

If that truck sat for a year, and it still has the same tires, you should check them out.

 

Sounds like the first order of the day is to change the oil (NO additives) and filter, get rid of the red fuel - if it's still in there and change the fuel filter. Actually not a bad idea to change all fluids & filters just so that you know what is in there. Next step would be Hutch and Harpoon mods. Kind of sounds like fuel starvation at least.

 

First off, welcome to FTE!!

Second, you have a generous Dad. Two of my sons continue to ask me if I'm willing to "pass down" my 2002 F250, but it's my DD, and, well... NO. I can't.

Anyway... to your issue.

Could be fuel flow problem. (my first suspicion)

Could be drive line imbalance. (u-joints, center carrier bearing, etc.)

Both of those systems are known potentials for raising their heads at the 40-45 mph point.

Drive line -- does the vibration happen only when you are maintaining speed or accelerating, and then disappear completely when you let off the throttle? Yes = driveline issue. No = probably something else.

 

I'm on the fuel flow bandwagon, too. What was the fuel level when it happened? I definitely wouldn't jump right into trans diagnosis and swaps.

 

Another possibility is dragging brakes from dried out slide pins. They heat up and get grabby. Put your hand near the front hubs after it happens; if that's the problem you'll feel the heat and prolly smell the pads.

 

The fuel has been on low fuel when it happened and it has been completely full I have been trying to get all red diesel out of tank and today I got it to 50 mph with only a slight shudder it really happens bad when I try to accelerate up a pretty steep grade and it always only happens in 4th gear

 

Well that's a whole different ball of Cheese, I suggest you're Fuel Pick-up Foot has crumbled to dust and you've sucked most of it into the pre filter....Time to drop the Tank!

 

How fast are you going in 4th? Manual or auto trans? Sounds like it may be a combination of the bad fuel and/or lugging the engine in too high a gear.

 

it's an automatic trams and like I said as soon as it shifts into 4th gear at 2000 rpms and 40 to 45 mph most of my driving is done in the at 30 to 45 mph

 

I hope these guys are right about the fuel...got to give this more thought.

 

Yeah me too I will start with the fuel but I will still be checking in for more insight