Brand New 4Runner and Rotor RunOut

Hi everyone,, I was going to join the forum but this issue that I have with a brand new 4runner made me join sooner than I expected.

To give a background story, I recently purchased a Brand new 2024 4Runner TRD Pro from a dealer.

i am now about 1,500 miles in, and I’ve been noticing my steering wheel rattling or vibrating around 40~50 MPH. I initially thought it was due to the rough road surface, but also doubted an alignment issue which made me to schedule a service under warranty.

After they diagnosed, the dealership said there is a rotor runout caused by the rotor over heating. Their proposed solution is to cut the rotor so it no longer scrubs..

Does this sound normal to you at 1,500 miles? I’ve never seen this before for a brand new car.

They are claiming the rotor was probably not perfect from the factory(the error or the tolerances from the factory etc etc). But I think the factory does precise diagnostic when they first build the vehicle..?

I personally think cutting the rotor would not solve the root cause of the runout..

A root cause I can think of is:

Sticky Caliper or related system that causes the caliper to not release at the correct time.

This caused the caliper to make the brake pad to rub against the rotor, causing the overheating. So I assume the brake pad is probably affected and the rotor is warped for sure..

Do you think the dealer’s proposed solution (cutting the rotor) is the right way to go..?! Considering that it’s a fairly new car, I think I should request a new rotor, new caliper and the brake pad.. I attached couple pics for your reference..!

Any opinions would be appreciated!

 

Generally, steering wheel shaking (without braking) is related to tire/ wheel balance while vibration/ shaking while braking would be something to do with the brakes.

Unless this issue occurs only while braking, I'd have them check the tire/ wheel balance. (From all the posts regarding this, 4runners seem to be sensitive to tire/ wheel balance)

 

thanks. I agree.. I was originally going in for an alignment because the vibration comes and goes during the driving and not during the braking. Apparently they found a separate problem.. and while they were test driving, they couldnt replicate the vibration while driving as it comes and goes..

 

It's not your brakes causing the vibration. It's a well documented issue on 5th gens

 

Can confirm on t4r 5gs being sensitive to tire/wheel balance. I usually have to get atleast one rebalanced

 

Yeah, the shimmy at highway speeds is usually a balance issue. I personally suspect bad alignment (specifically caster angles) makes it even more sensitive to developing these oscillations). From what I understand, the Pro trim is lifted at port via the fox suspension, and they may not do a great job realigning the front.

Even tire pressure can contribute to a tendency for the steering wheel to oscillate. Sometimes these are delivered with excessive tire pressure and nobody bothers to check during the pre-delivery inspection.

All this said, something is up with the rotors. Is that both of them? They kind of do look scorched (not sure, but almost to the point of blueing. On rotors that havent even worn off the hashing finish. Very weird. I would prefer they show more curiosity about upstream causes for scorched rotors. But, it’s warranty, so it’s always going to be one slow excruciating symptom at a time. Which is a shame. So eventually you’ll probably have to be patient and let them do it their way, or just pay somebody to actually figure out the issue with the brakes.

 

Thanks everyone for chiming in.
Yeah, I requested for a quick alignment check since they said they are not gonna document it so I can get it aligned once more with warranty. It came out passing..! I wonder if a tiny bit of tire pressure and misalignment could cause that oscillation, and maybe it’s a well known issue for pros.. I couldn’t replicate the problem with the technician sitting in the passenger seat, as the problem comes and goes and doesn’t occur 100% of the time. I guess time will tell at this point..