Passenger seat shaking on highway

Wondering if this is normal? Seems pretty intense especially with a trailer behind the runner at highway speeds. No noises though. But damn...these things love to shimmy.

https://youtube.com/shorts/npjSmQZSkiU?feature=share

 

Weird! If you stick a camera on the side of your truck looking at the tires I bet one is jumping around like crazy. That vibration is being transferred in from somewhere. Look there first.

 

I just noticed this as well on mine this AM! I think my tires are not properly balanced.

 

When I google searched I found a lot on the Tacoma forum about this issue. Just another quirk it seems like. Mine is most certainly worse when towing. When this happens the vehicle feels smooth, not even any steering wheel shimmy.

 

Not towing, but I don't feel anything in the steering wheel either. I'm getting my tires rotated and balanced tomorrow. I'll post if it appears to eliminate the seat shimmy.

 

My highlander does the same thing on smooth roads, but with a back seat. That car has always been perfectly balanced, and doesnt suffer from shimmy. The seat bounce/shaking is not a shimmy, it’s not cyclical. It’s a response to bumps. It takes longer to stop shaking than I expected, but does not sustain. These seats are lighter nowadays, thats probably why they move around a bit more.

I subjected myself to a few questions when I discovered my shaking Highlander seat. Thanks to yous guys, I am sure I’ll ask myself these questions again when I look tomorrow to see if my 4runner has the seat shakes . I usually apologize for subjecting anyone to my internal thought process, but I hope it helps anyone wanting to tempt fate by having a non-shimmying 4runner rebalanced.

Q1: When in my life did I previously look at an empty seat beside me while driving…for any length of time…whatsover?. A: Good question, I cannot recall.

Q2: Why am I currently looking at it? A: Well, it’s shaking, duh

Q3: Is it loud? No.

Q4: Is the person sitting in it bothered by it? A: Not really, but that’s only because nobody is in it.

Q4: Ok then, when somebody is sitting in it, are they bothered? A: No, but that’s only because it’s not shaking.

Q5: Sigh…. Try moving the seat-back position a little…more vertical. A: That’s not a question.

Q6: Move the damn seat! A: OK! Jeez, there….. I guess that might be a little better, but Im not sure, I’d have to look at it longer, under more road conditions…

Q7: Stop looking at the seat and get your eyes on the road. A: That’s not a question either, and you can try to say it more nicely.

 

It’s because it’s designed for an occupant to enjoy the adventure with you.

 

I will still accept these quirks over electrical, transmission, lifter, head gasket, rear differential, infotainment, and engine failures with ‘other’ company’s.

 

Discount Tire performed a road force balance on my rig (Hunter machine and correct adapter). I haven't had a chance to get her past 45 mph yet which will truly tell me how well balanced they are, but the passenger seat still has a shimmy. Ugh. Guess it wasn't from tires afterall.

 

Seriously, it’s just a tolerance design thing. I brought it up when I purchased my 18’ and we checked several other 4Runners on the lot. All the same.

My 97’ Tacoma passenger seat did the same thing.

 

I have gone through this process many times with techs being able to use the equipment correctly, training, training, training. If a tire is a little out of round, or slight defective it usually can be balanced out to an extent. If it’s to far out, then it needs to be replaced, Same with the wheels. I would suggest that you do not accept it as is, ask for their best guy. If he can’t get it done, then be prepared to take it elsewhere. I run 285/70/17 MT’s and go to the same shop for years, sometimes they nail it, other times i take it back and tell them i have a little shake, and i know it not terrible but it drives me crazy. Smooth as glass on the way home. Be persistent you do not have to settle for the way it is. I hope you get it taken care of and it puts a smile on your face, stick to your guns.

 

@4runGirl88 Did you think you had out of balance tires because the seat was shaking, or because you were feeling a vibration (steering wheel, floorboards etc.?

Can you tell if your seat shakes because of road surface texture or bumps….or is it a constant shake, even in smooth roads?

 

I've noticed some vibration when going 50+ mph. I thought it was my right rear tire, and have since had tires rotated and then it appeared to be more in the right front. I only noticed the passenger seat shimmy about a day ago. I was planning to get my tires balanced before I noticed the seat shimmy. Figured the 2 were related. Seat shakes alot over bumps and uneven road. But today I noticed it shimmies constantly. I don't feel the vibration in the floor after today's balance, but I haven't driven 50+ mph yet either.

 

I notice some vibration in the 2018 F250 I drive at work, as bad as the 4 runner no, but it’s a bench seat and I never have the opportunity to put a trailer on it and go 60mph + so that made me feel better.

 

Do you experience the steering wheel shimmy around 55-65 mph?

 

Steering wheel shimmy is brief at higher speeds. I felt vibration mainly in floor if that makes sense? Like a tire bouncing along.

 

Also found this thread on seat shaking:

https://www.4runners.com/threads/passenger-seat-shake-experience.8160/

 

You are another blessed with that I see, maybe the vibration you feel in the floor is the needle bearing, I felt a rotational vibration in the floor and could also hear it and feel that in the steering wheel as well.

 

I only experience the seat shaking when the seat is pushed all the way back and nobody is sitting in it. The way I understood it, there is way too much of the seat behind the mounting points when it’s slid all the way back. With a passenger, their weight holds the seat still. I actually read about the issue before I ever experienced it (I have a small fiancé, so the seat is only ever that far back after I sit over there, or after cleaning). When I did experience it, it was as simple as reaching over and sliding the seat forward, and that was all she wrote. Hope others experience the same easy solution.

 

Wow I found some people more anal than me. Thankfully y'all exist. I don't think I have passenger seat shake and I'm not going to look, but I get it because when I was looking for another 4R I chose the SR5P over other models because I hated seeing the transfer case shifter shake on my Pro.

 

LOL! I also enjoy knowing I’m not the only one “blessed” with an attention to detail…as annoying as that can be.

Somebody quoted that thread with the idea to slide the seat forward. I think that might be the silver bullet.

 

Well as far as that suggestion goes, I will say that I remember on my Pro I had a rattle in my drivers seat. One small pulse of the electric seat control and the rattle went away so adjusting the passenger seat might be the solution.

 

So, i'll go ahead and chime in on this... As silly as it may sound, i just had an alignment done at my dealership after adjusting my settings on my Eibach suspension, and after the alignment, i stopped getting the passenger seat shake. Turns out that somehow, my toe-in on my passenger wheel was off. (-0.37). They adjusted it back to (0.14), and even the truck drives better. No longer getting the shake as well. Your mileage may vary!

Cheers,

Sean