i have a vibration its not coming from the front i thought it was tires so i got new ones and it still vibrating anyone know what it is and it starts around 30mph

 

possibly a bad U joint.

 

U-joint is a good possibility, but I'd check the tranny mount first. $15-17 from Rock autoparts.

 

An easy check to see if its the rear u-joint is to just get the car up to a decent speed (over 30) and push the clutch in. If the vibration persists even though engine rpm has dropped to idle , then chances are its the rear u/j. It will get worse the higher the car speed...if vibration is reduced or gone then yeah its trans or motor mounts.

 

ill try it tomarrow if its u joints should i get a new driveline from junk yard

 

gradually increasing engine rpm while sitting still will also determine if it's engine/tranny mount related. but i have done the same thing, pushing in the clutch while going down the road to determine where a vibration is coming from.

 

i was doing that today and it was not doing anything so it must be the u joints then

 

What if you have a bad vibration at 30+, vibration stays when clutch is in and coasting at any speed.

Thought it was a rear U-joint, so I replaced that.

Checked all tires for balance.

174k on an 82 GSL. The car drives great and handles fine, but the vibration is almost making it undriveable.

 

put the car up on jackstands and go through all joints. At 174k you're probably looking at new ball joints, inner and outer tie rod ends, both u-joints, springs/struts, etc.

 

Could be front U-joint or the whole driveshaft is out of balance.

 

check your brakes