New 2019 Tacoma Shaking at Highway Speeds???

Recently purchased a used 2019 tacoma sr5 DCLB with 30k miles from a dealership… Ever since I drove it home it has has a very weird “shaking” sensation in the seats and floorboards and I’m not sure what it could be? Mainly occurs when I’m going down the highway around 70-80mph, and sometimes the steering whee shakes but it happens on and off… I brought it back to them the first time and they balanced my tires… Drove it back home and it still had the same problem so I called back and they told me they needed to replace a rear left tire? After they replaced it it fixed the problem somewhat but there is still a shudder/shake when I drive at higher speeds… Anyone have any idea what it could be? I want to milk the living s**t out of this warranty so I can get it fixed ASAP… I don’t think it’s torque converter shudder. There’s no noise when it shakes besides the sound of the seats rubbing against the doors… Pls help.

 

Typically if the passenger seat shakes at high speeds its tire imbalance.

Tires have lots of variables and if they arent new there's not much the dealer can do beyond balancing them. You can try to have them rotated to see if the issue worsens.

It could be a driveshaft issue, but is less likely. Usually lower speeds and on decel.

 

Definitely going to rotate tires by the end of this week, just had a email from carfax stating the tires were due for rotation after about 9 months so I’ll see if that fixes anything and I’ll report back here. Thanks!