im going with a 5.slow cant even tow a small utility trailer without vibration

 

According to my calculations, it is your trailer causing the problem. However there is a slight possible chance that perhaps the road is causing the vibrations. It is also entirely possible that your 5.slow is trying to shake that dead weight off it's rear end.


Conclusion: More testing, calculations, and information is needed to assist you in the resolution to your vibrations.

 

haha i love it!