Slight "thud" on moderate accel from standstill
- Thread starter Bucky1
- Start date
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iamdub
Full Access Member
Remove the marble from the pocket in your door panel. 
My guess is it's the ever-so-common driver's side engine mount. Pop the hood and watch the engine through the gap where the back of the hood meets the cowl. Hold the brake firmly and, with the trans in D, give the throttle a sharp jab. See if the left side of the engine jumps considerably and has a corresponding thud. Confirm by checking underneath for a rust-colored chalky substance all around and on the engine mount(s).
My guess is it's the ever-so-common driver's side engine mount. Pop the hood and watch the engine through the gap where the back of the hood meets the cowl. Hold the brake firmly and, with the trans in D, give the throttle a sharp jab. See if the left side of the engine jumps considerably and has a corresponding thud. Confirm by checking underneath for a rust-colored chalky substance all around and on the engine mount(s).
You can also look under the truck at both your front and rear sway bars and end links, see if one is broken or missing, if one is it will move every time and smack under the body
iamdub
Full Access Member
I was just about to say to grease the slip yoke splines. Does it seem to do it only once when accelerating after you've braked to a stop?
Mine turned out to the front differential mounts after everything else had been eliminated.
Yes it does. About the time the truck starts to rock back, and the tires starting to turn you hear/feel it.
iamdub
Full Access Member
Classic slip yoke binding when braking then breaking loose when you let off the brake or accelerate. It's quick and easy to remove the shaft and grease the splines to at least rule that out as a cause.
HiHoeSilver
Away!
Or worn u joint.
