Daughter purchased new and 1200 miles started making noise and vibration. Dealer had for close to 4 weeks and replaced front diff. Now 17k miles and started making same noise. Same known problems dates back to the 2005 Tacomas, same running gear. East Coast Gear Service has a fix. Taking back to dealer this week, multiple You Tube videos on the problem. Shame she spent over $44k for such old unreliable tech. 4Runners are still made in Japan was the reason and new one is going with a turbo 4.
So any car and any manufacturer can end up with a lemon which is why there is something called lemon law. The 4Runner has proven to be a reliable car and it's not like Hyundai/Kia which have ton of problems constantly. I would suggest first have a trusted independent mechanic check it out and tell you what the actual problem is so you know. Then take it to the dealership without telling them you know the issue and give them another chance to fix it. In the meantime get familiar with your state's lemon law and go that route if needed. Either get your money back or ask them for another one; 4Runners are reliable.
It is a well known problem with Tacomas and 4Runners all the way back to 2005. My 05 Tacoma had the same problem, go to any of the forums and it is documented. Have to give them 3 tries to repair in Tennessee for a lemon law to come in to play. Toyota was supposed to address this back in 2020 or 2021. Thanks for the reply though.
The 4Runner is still a very reliable car and there are a lot of people happy and satisfied with this car, and pretty much the consensus on this forum too. I do understand it can be frustrating having issues with a brand new car but on thr bright side you do have the lemon law and the 3 attempts is pretty normal across most states. So just let them have the 3 attempts (they've already used one), document everything including how long car was in shop for a fix and then either get your money back or a brand new car. Not every single one of them has and will have this issue and in that category 4Runner is the best option out there.