2007 Dodge Ram shimmy in 4x4 when speed up

[pope]

i have a 2007 dodge ram 1500 and when i have the truck in 4x4 and i get going about 80km/hr it starts to shimmy a little bit in 2wheel drive its fine

[ProTech]

If it only happens while the truck is in 4WD, then it will usually be something from the transfer case forward. This could be a front driveshaft that is out of round, or out of balance, or a bad u-joint. It could also be something inside the transfer case, but that is probably the least likely area.

A problem in the front differential or axles can cause a vibration/shimmy when they are engaged, so you might want to check there too.

Lastly, if the front tires are worn, or out of balance, or even with a bent rim....it would become more noticeable when they are being driven in 4WD.