Help Bad Vibration From 60mph and up
 

so i have noticed it getting worse, i have a terrible vibration from 60 mph and up, it feels like a badly worn tire or unbalanced wheel. but its not as i just re balanced them all myself and just put newer highway tires on for winter time. also all the upper and lower ball joints, track bar and wheel bearings were replaced in last 5000 miles. anyone else have or had this problem and what should i look at to fix it? i also checked the u joints on my rear drive shaft today and they both looked good, could not see any play.

slack in your gearbox maybe?

In my NV5600 or my steering gear box? it gets worse as i go faster, i took it up to 95mph today messing around and it sounds like bad wheel bearings to be honest. not sure how thats possible though since i just replaced them, maybe i will throw it on the lift and run it in the air to try and isolate were the noise is coming from.

Since yours is a 6 speed, is the vibration better felt in the steering or the shifter? I ask because i suspect a driveshaft carrier bearing depending on how many miles are on the truck. My friends 12v had a bad carrier bearing and it would only vibrate above 50 or so, felt like slight out of round tires. It was way more felt in the shifter than steering wheel.

U joints tighten up before they get play in them and that will cause vibration. The only way to really check them is pull the shaft. The u joints should move freely in any direction, if they're tight and don't move freely they're bad. :c:

i was thinking u joints too, because there is no vibration in steering or shifter, i only have 125,000 miles on my truck and they look original, they dont have any grease fittings on them i checked for play yesterday. pulling the shaft wont be too bad.

death rattle
 

Could be the notorious desth rattle of the 2500 frame it gets shaking at a certain frequency at certain speeds. I had to get an aftermarket reinforcement bar to get mine to stop.

At exactly what frequency does the frame get death rattle ?:humm: I wanna be sure not to tune to that frequency :tu:

my cummins did the same thing check the axle u joints and the front. they tend to get over looked. mine was the front u joint of the front drive shaft. at exactly 60 mph.

Have the drive shaft professionally balanced - it's cheap and effective for removing unwanted vibration. Install new U-Joints while your at it - nothing like a broken U-joint to wreck your day. :argh: