Weird Shudder/Vibration
 

So I have a 2001 2500 4x4 QC CTD.....I have only owned it about six months but there is a issue that seems to be progressively getting worse. MAINLY on the freeway, when I get into it really hard I get a VIOLENT whole vehicle shake, if i let off of the gas it immediately goes away. It seems to be aggravated when I have my Edge Comp box on, but will do it at a much less level even without it. It also seems to do it with the shift going into its final gear. I have become a pro at feathering the pedal to keep it less noticable but if I harp on it it feels like the truck is going to shake apart. Once cruising along never feel a thing...smooth as can be, once a hill comes up and have to give it the gas comes back again until i let off. In the city have NEVER felt it even if HARPING on it, it seems to me has to be in a higher gear to feel it. I know this topic has been asked but it seems every scenario is different, so i tried to be very specific with my particular situation. No other shifting/vibration issues other than this one. :argh:

Auto or manual trans?

automatic...sorry

Does the steering wheel shake making the truck hard to control?

nope....its pretty much a horrible vibration in the body...so much the dash even shakes but not so apparent in the steering wheel. Driving control is unaffected.

Check the u joints in both drive shafts. If there is any play replace them. Turn overdrive off and see if the vibration is still there. I am leaning toward the torque converter clutch is slipping on you which would require replacing the t/c. Might try a trans fluid/filter change.

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Also check your tires for any bulges or tread separation

Check to and see if your tires need re balanced. Sounds stupid but i did it and found out one of my tires were out of round mustve been to much mississippi drinkin water that night.

Wooooo! Death wobble! Lol

It may be your tires, my dads 08 6.7 3500 is HORRID because the tires are unbalanced

Check your engine mounts too.

I'll bet it's torque convertor shudder. You need a convertor. On my 01 it shook so bad the dash vibrated. When you let off the throttle the convertor unlocks. I knew my tranny had been rebuilt a few years earlier so I bought a single billet convertor and installed it myself. Problem solved. Don't waste money on a stock convertor, they were marginal stock, and with any programmer at all they will fail.

my little jeep turbo diesel get torque converter shudder pretty bad when it locks into overdrive when you get on it. especially when i turn the programmer up. so the converter is def. a possibility.

so now it probably is what i thought it was
 

What is the most cost effectivee replacement that is good quality and will handle some mods and doesnt cost an arm and a leg.... For a replacement torque converter....and thanks for all your help.

Suncoast makes a good convertor. I found tons on ebay, but ended up finding one out of Calgary for $600ish. Just search 47re convertor. Most tranny shops won't want to just replace your convertor. Make sure you replace the front seal and check the flexplate for cracks and flush your cooler lines when they are unhooked from tranny. Lastly set your bands, and put a new filter in the pan. Pull your pan first and make sure there's no chunks, otherwise just rebuild the entire unit.