New to towing 5'r question

I just bought a 2004 32' toy hauler and am towing with a 1999 F250 superduty 7.3 diesel.
This is my first time towing a 5th wheel and while going down the road I get an intermittent small amount of jerking front to back.
It's not huge but I'm just wondering if this is normal with a 5'r

Thanks in advance