Okay so I have some vibrations in the truck at pretty much 40+ mph, them being worst at 40 but get smother towards 70. These vibrations will get worse in a corner as well. They were there when I had ifs, now i have sfa with all new stuff and its still there. So I checked the drivelines and there was some slope in the ujoints, so I replaced with new. Vibrations persisted but little better, then I noticed the driveshaft was out of phase and had a bad angles so I fixed that, but vibrations persist, not sure what to try next. Thinking of getting the tires checked for balance or getting some of the auto balancing rings. The vibrations are just really irritating me, what would you guys suggest? Sorry for the long read. Truck is a 1990.

 

Most likely mud and dirt buildup on the inside of the wheels. Happens when you park it after a day of mudding, or driving in the wet, then park, and the dirt builds up in one spot. Take it to the car wash, or spray them out with the hose at home.

 

yea, getting your tires checked for balance would be good, but you also my want to consider a front end allignment. some places like les shwuab will check your allignment on a machine for free. as I've noticed though, every car has that one speed that just doesn't feel good, like for my yota its 45mph

 

Yeah the tires and wheels are pretty clean so I don't think it is mud buildup. The tires are an older set if that makes a difference, starting to crack some. Forgot to mention that I just got a front end alignment and it didn't change the vibrations at all and they said the front end was tight.

 

hmmm... yea possibly the tires, or some other suspension issue

 

Does the frequency of the vibration follow with the driveline/ tires or the engine (throught the gears)? If it is the driveline/ tires, does the frequency match the driveline or the tires?
1. if it is the frequency matches driveline, check u-joints and hanger bearing.
2. if the frequency matches the tire speed check balance, mud in wheels and alignment.
3. if the frequency matches the engine speed, check engine mounts.