I have my old faithful vehicle. Not much but worked for me for over 10 years. Ok here is the problem:

Installed new brakes, tires, axles, motor mounts, transmission, struts, and shocks.

Vehicle has 198000 miles. 3.3L Grand Caravan SE 1990

First off the vehicle when you apply the gas a little and let off bumps. Acts like UJoints if it had them. Tranmission shop says it's not the transmission.

Second. When you apply the gas in drive the right front shakes. Transmission shop says don't know. Goodyear who put on my axles says its new axles.

In fact I had Goodyear put 3 sets of axles and motor mounts on because everyone told me that was the problem.

Anyway any assistance would be greatly appreciated. I have been moving this around now to 4 shops and nobody knows.

 

Without being able to drive the van it's going to be difficult to diagnose the problem.Could it be that the engine has a miss?Spark plug wires do wear out and if they haven't been replaced it could be something like this.They will cause the enine to miss worse when the engine is under load.An injector could be worn out also.
Here's a link to an engine and vehicle noise description guide.Look it over and see if it helps when describing the noise/vibration.
http://www.bullittarchive.com/WebHel...escriptons.htm
It is on a Mustang website but it's pretty much universal.