I get a vibration at 40-45 goes away when on gas ,comes back when I let off, same thing around 70 very noticeable when taking foot off of pedal, I know it needs left lower ball joint . Don't think that would cause it,front hub bearings are one year old, any help please, tires only 4 months old

 

Vibration is worse in 4 hi and will not do it under load ,just coasting, will removing front shaft help to narrow this down, thanks

 

I was going to say to check for wear on parts of your driveshaft/s, or damage.

 

Thanks Ron, I was under truck today changing the oil and everything seems ok, only thing I found was the tensioner pulley appears to be going bad, bearing is making noise,has new rear u joints and companion flange , front drive shaft and u joint has 149000 miles, transfer case and 4 hi and low work great, I have life time balance on tires so will start there, if you think of anything, please let me know, thank you