Has your truck ever bucked at about 70?

 

dont know what you mean, but i've gotten loose on a gravel road at 70

 

Maybe you're talking about the front end shaking? Look up "death wobble", probably find more reading than you ever want to do.

If it's an engine thing, can you explain a little more? I'm sure someone will be able to help you out.

 

Hi!
my truck is a 97 dodge 4x4 3500 5sp club cab large injectors,TAG, AFE filter timed@15 straight pipe 410difs truck has 258000 miles
I have had the truck for over 4 years,it has always shook or bucked a little,but has steadily gotten worse.
I have changed all the tie rod ends, put in urethane bushings,ball joints,u-joints carrier bearing,drag link.
It acts like the wheels are out of bal, and I have worn out 4 sets of tires over the cource of 152000 miles, I even bought a set of wheel ballance disc that go behind the wheels.
But the shake is realy bad at 73-80 mph interstate speed.
Is my clutch? (Also changed) or the springs, motor mounts or what?

 

Just throwing this out there because you did not mention it but have you checked to see if your bushing for the cab mounts were tight and have not rotted away? your cab could be loose just a far fetched idea but it dont hurt to cover that. On second thought while your there might see if the bed has come loose too we have a old chev that we feed off of and the bed or the cab both are loose and it feels like the thing is goin to fall off there but were putting a flat bed on this winter so we have not delt with it

 

I had a 96 1500 318 that had a bad pitman arm the ball joint wasn't on the drag link it was on the pitman arm and was shot! It had an uncontrollable shake until I replaced it. You could'nt tell it was bad until I droped the drag link and wiggled it. Does it ever shake when you are braking?

 

Another thing to check is your driveshaft. Bad ujoints maby? I always have my driveshaft ballanced every couple years or so. But none of that should effect the front end. Unless you have bad rims, shocks,or springs there is not alot left for you to replace.