Help, can't cure this vibration. Driving up to 50 mph, nothing. Then when I get to 70mph, it wobbles like the wheel is out of balance. You can drive through it and when you hit 90 mph, it goes. Interestingly, I changed the wheels to my spare set and the vibration was worse!! I've changed discs, DMF and mounts except the gearbox one. I've also changed the passenger side drive shaft. Tyres are also fine. Its it's driving me crazy.....
Check all wheels are sitting flush on the hubs. If they're not then every wheel you stick on will do this.
I had a similar problem as I bought my 175 with ditch finders on it. Soon as I put some decent tyres on the problem totally disappeared.