Wondering if this is normal...

Agree with @seydou , if it shimmy’s all the time, that ain’t normal, mine does not do that. If it shimmy’s a little when you hit a bump, may also not be normal, but mine does it too, and my buddy’s 21 CM 4x4 feels just like mine does.

 

Michelins shouldn't be difficult to balance; lower speed vibration may be sign of a bent wheel... yes, you can balance a tire (zero it out on the machine), but still get a low speed vibration from a bent wheel. This type of problem will normally be constant though. One way to check for this is to remove tires from wheels, spin the wheels, and see how they come up.

Another issue that we get frequently w/stock size tires is them holding small rocks; the OE Michelin LTX AT2s are more notorious for it than the defenders. So, if you live on a gravel or dirt road you may frequently being holding rocks, and if you think about it, 10 or so small rocks stuck in the tread could throw your balance off (which you should see more at 55-65 and not low speeds).

Others have mentioned making sure the wheels are seated properly. Make sure you have the correct lug nuts for your wheel type (this will give you low speed vibration and emulate a bent wheel).

If the vibration is more steering wheel (front tires/wheels), rotate the tires and see if the vibration changes to your seat/floorboard (rear tires/wheels) and vice versa; this process may help you narrow down your issue.

Finally, air pressure should cause vibration. However, if your tires are over-inflated, you may 'feel' more harshness along the road particularly over bumps and such that may give you the sensation that you're having some vibration, but in reality you're just getting a bit of a jarring affect. So, the fix here would be to lower PSI a bit if they are over-inflated. Tundra isn't a 'plush' truck, so you will 'feel' the road a bit more than you might w/some other brands, but we'll take that over the damn thing falling apart before 100k

Good luck on finding resolution, and enjoy your rig!!!

 

Shimmy in the steering wheel, No not mormal....My OEM Bridgestone tires were fine, the Michelins were horrible, the first set I returned. The second set were fine, no shimmy, for a while then it started again... No balancing would solve it. They were replaced by Nokian and no shimmy or vibes..