Okay so just recently, My 2004 Ford Ranger started doing this shudder, bucking up type deal. It does it in O/D pretty bad when going uphill and on the highway, It'll do it pretty rough under mild acceleration. I haven't jumped to conclusions yet but my guess may be either, Torque Converter, TC Solenoid, or a bad Valve Body. I have checked the fluid and it looks good and clean, doesn't smell burnt, and is full. It has 161,xxx on it. 4.0 4x4.

 

My guess is misfire.

 

Okay. Ill check plugs and wires once I’m home. I’ll post back and let you know what the outcome is.

 

Welcome to FTE.

^+1 on a misfire, I like this idea as the symptoms fit the engine mileage & under load scenario nicely, if these are the OEM factory plugs.

If these are the OEM plugs & wires they're over due for scheduled maintenance replacement & Motorcraft iridium enhanced fine wire center electrode, with platinum pad ground side wire plugs are recommended with our "waste spark" ignition system, that works its plugs, wires & coil pack Twice as hard as the old distributor system, as it fires them on Every rotation of the crankshaft. So the newer fine wire plugs are designed to take this extra work load & have the spark gap remain in spec Much longer. Motorcraft wires are a nice piece of work too.

With 144K miles on this puppy a number of scheduled maintenance replacement items are over due, so take the time to read up on whats due & get the vehicle up to date on its scheduled maintenance replacement fluids = tranny fluid flush & filter, differential fluid change, grease front wheel bearings on 4X2 vehicle, brake fluid flush with Motorcraft DOT-3 fluid, filters like fuel, air & tranny, spark plugs & wires, PCV valve, O2 sensors, serp belt, coolant hoses come to mind.
I'm in the process of performing my 90K scheduled maintenance on all of the above on my 99 4.0L as weather permits.

If you don't have a owner manual, or scheduled maintenance chart to look up whats due on your 2004 4.0L, you can download one at no cost here. Owner Manuals | fleet.ford.com

More thoughts for consideration, let us know what you find.

 

Misfire will trip the check engine light (CEL), severe misfire will cause the CEL to flash. You can also test for misfire by stepping on the gas a bit with the vehicle stopped and your foot on the brake.

 

In my experience, it takes a lot of symptoms like are described here before a CEL illuminates.

 

So I checked the plugs and that’s what it was. Thanks for the help and also thanks for saving me time and money. Usually when I feel shutter I think transmission but I was wrong on this one.

 

Good find, feedback & to hear all now seems better & your satisfied. Would be interesting to hear if these were the OEM plugs & what the spark gap looked like after 161K miles.