Vibration starts at 40 mph in the front end have replaced cv shafts, hubs, u-joints you name it has een replaced. When the front drive shaft is out no vibration only when its installed.

 

Have you checked the IWE?

 

Yes, replaced both and vacuum lines

 

Then it's likely a problem with the front driveshaft.

It may need to be re-balanced.

 

Did you index the driveshaft when you removed it? If you didn't, then it's assembled wrong. The spline shafts have to go back the exact same way. You can be off a spline and you can be 180 degrees out. Remember, the entire driveshaft was balanced from the factory as a complete unit. It has to go back together just like it came apart.

 

Yes I put the shaft back in the same way came off after replacing u-joints. Vibration was happening before and still going on. Maybe I should have drive shaft looked.