Vibration at speeds over 80 mph

So I have recently noticed a vibration on my 2011 dcsb trd off road when I'm on the interstate around 80mph+. It just got an alignment done and tires have been replace and balanced as of 6 months ago. Doesn't seem to happen all the time, its got 106,000mi on it. It does have a 3'' spacer lift on front and back, and have had to replace the cv axels and ball joints (but i like to push her little hard when I'm 4wheeling). Other than that the trucks been a beast and is in perfect working condition. Im wondering if its coming from the drive shaft or maybe a tire is worn little different from the rest. Any input helps!

 

I bent an inner tie rod end and had the same issue. Replaced it, and had an alignment done, hasn't vibrated since.

 

Carrier bearing ​

 

It may be as simple is getting your tires balanced again. I would start there. 6 months is enough time for them to become out of balance again. How many miles have you put on in those 6 months?

 

Definitley a better idea to start cheap.... Lol

 

Hmm i did hit a big rock that made my driver side toe way off thats why i got it aligned recently, made my steering wheel about 15 degrees off. So maybe ill start with the driver side tie rod.

 

Ive probably put close to 10,000 mi on new tires

 

2nd for carrier bearing

 

I hit a big mude hole when I bent mine. Jack your truck up and check for play. That might be a good bet!

 

Thanks for the input guys ill get under it today try to check out some things.

 

I have a similar situation going on... Does yours change with how much throttle you are giving it? Mine starts to vibrate at around 80mph as well, and then when I let off the throttle it gets a little worse... I have a one pieve driveshaft, thinking of getting that re-balanced..

Anyways let us know if you find out what it was.

 

80 mph with a one piece on a DCSB is a critical speed issue. Depending on gearing and tube diameter.

 

Can you elaborate

 

Well, I'mm guess your Drive Shaft is 67.5 flange to flange, so lets say 63 joint to joint. using the spicer calculator http://spicerparts.com/calculators/driveshaft-safe-operating-rpm-calculator you can calculate safe speed. You will need to calculate the shaft RPM based on tire diameter and gear ratio. See spreadsheet for tire size and gear ratio.

I was thinking about doing a one piece for my DCSB but that would limit me to 75 to 80 depending on driveshaft size.




So depending on if you have a 3.5" or 4" shaft the safe RPM could be 3200 to 3766.

The spicer tool does have some safety factor built in so i don't think your drive shaft will explode if you exceed that number but you will get vibration.

This is why i am going down the road of a custom 2 piece.

 

Very interesting, will have to look more into this.. Thank you