1990 f250 shakes and bucks

Hi, you could check your engine mounts.

This may a serious problem that may cause you to have a bad accident. Please take into a service shop ASAP and have them check it out.

I bought a brand new car, took it for a run,got up to speed and the car started shaking. Took car back to dealer a few times. Eventually they said to put on "Michelin" tyres. Problem fixed.

Struts

Although you didn't say if it feels like the shaking is coming from a wheel, it sounds to me like you have a bad tire even though they are new. Take it back to where you got the tires and have them take a look. If they can't see anything, ask them to take it for spin.

Wrong, it couldn't be the battery because the battery is basically used to keep track of the time and make sure your car starts, after it does the battery basically charges and runs like the radio etc. The fuel filter would be more likely, but my money's on the fuel pump itself. You might also have an engine coil firing out of order, which would cause the shaking and an occasional **** from the car.

-Get a tune up.
-Get a machine hooked up to your car by a mechanic (full systems check)
-Check the transmission fluid.
-Tell the mechanic that it's probably the fuel pump. The fuel pump starts going bad, and then your gas gauge starts fluctuating, and your engine starts struggling to get to higher RPM's because it can't **** fuel out of your tank fast enough.

All in all to get this baby back on the road at full force could run you 200 to around 500 dollars. Then depending on the mechanic the labor is more.

Tune up (100 bucks) transmission fluid change(20-50 bucks) Full systems check (50-80 bucks) fuel pump(150 bucks) then the labor for everything would be anywhere between 150-300.

Hope it helps.

check your u-joints

I have this same car with exactly the same problem. Begins shaking at 40mph and stops shaking as soon as you let off the gas, but then begins again as soon as you press on the gas and smooths out as you get over 50. And the shaking is not felt through the steering wheel. Solution: Replace the transmission mounts. There are two of them, one on each side mounted on the frame right next to the shock strut. There is also a front and rear engine mount, but I replaced the two as described and shaking is gone.

You have identified the problem when you pulled the drive shaft and the shake was gone. So you know it is between the tranny and the rear end. If it is not the universal joints, then you have a warped drive shaft.

check your engine mounts