Cyclic vibe at 50 mph

So around thanksgiving I got new tires on the truck.... turns out two of them were bad and no one could balance them. After a few thousand miles of driving, I finally got them replaced and the truck drives much better... butttt now I can actually pick out a really annoying vibe that im sure is not related to the tires.

It starts around 45 and smooths out around 55 and is really really bad right at 50 mph. It is there in 2 and 4wd. It is there when I am on the gas and coasting. It is not RPM dependent. I can feel it ever so slightly (VERY slightly) in the steering wheel.

I have about 3 in of lift, have been lifted for a while and have not had vibes so it shouldn't be that.

I have tried jacking up the truck and checking wheel bearings. There is no noticeable play in the wheels when I shake them and there is no audible sound from them either. However, when I am turning, I get a weird almost grinding feeling in the gas pedal. I am thus thinking is is probably not a drive line thing. (but not ruling it out)

I have searched pretty extensively for vibes and can't find anything matching this particular problem. Any thoughts as to what it is? I really want to say wheel bearing but nothing is coming up when I check it. Any other ways to tell if it is bad? It is getting worse and I need to fix it ASAP.

Thanks guys!

(2006 V6 4x4 manual)

 

To me, it still sounds like the tires/wheel assembly is out of balance. 50 miles an hour appears to be the resonance frequency of your tires, which is why it goes away as the frequency gets higher. If your wheel bearings were shot, I would predict that the vibrations would get worse as the speed gets higher because the force on the wheel bearing is going to continue to increase as your speed increases.

Have you taken it to another tire shop to get another opinion on them? There is another way of balancing called 'road force balancing' that tries to measure how out of round the combination of the wheel and tire together is. A tire professional can then rotate when the tire relative to the wheel and to try to create an overall more round assembly.

I've never had driveline vibration issues with my truck, but that is also a rotating component that can suffer from resonance issues. However from what I've read, driveline vibrations happen at much slower speeds.

Hope you get it figured out!

 

Most speed sensitive vibes would be tire balancing. Like suggested, find a shop that offers road force balancing especially one that deals with oversize tires. Besides lift, you have also ruled out tire rub when turning? What size tires are you running?

 

Thanks for the replies!

I had my wheels balanced 4 times by two different shops before I had the warranty put in and the new tires put on. They have only been balanced once since then. I did try to get a road force balance but they said that my rims would not fit on the machine for some reason.... Maybe 6th time is the charm??

I am running 285/70/17 and they do rub a little while turning sharp. I am quite familiar with that sound/feel though.

From my reading about drive line vibes, it seems that they are usually at slower speeds. Though I am sure my U joints are getting pretty work after 100k. They are well greased and seem to be hanging in there!

The reason I suspect wheel bearing is there seems to be that weird griding feeling in the pedal usually when I am turning. Also, the shake is different than when the tires were completely unbalanced. Though with different tires it could be a different shake.

 

Th other think I guess I should address is tire pressure. I used to run Nitto Terra grapplers 295/70/17 at about 30 psi. they wore really well and evenly. I switched to Duratracs 285/70/17 and am running them at the same pressure. I figured this would work but need to do the chalk test still. I have heard under-inflated tires can cause problems that mimic out of balance tires.

 

Got it balanced... again. Looks like that was a lot of the problem. The vibe specifically at 50 is gone. The techs said one of the tires was still a little out. Might be getting a third replacement tire here soon....

Now that that vibe is less, the shake in the steering wheel is more pronounced. I asked the guys at the shop to check for play in the wheels and I have a fair bit of play in both front wheels. (They let me back to look for myself ) So looks like the bearings need some attention too.

 

Although it's not good news that wheel bearings are on their way out, good news that progress is being made!

The vibrations aren't happening only while braking are they? Warped rotors? Or I wonder if ball joints or tie rod ends could also contribute to a vibration in the steering wheel.

Good luck, keep us posted

 

With Tacomas poor track record with wheel bearings coupled with your setup of 33" tires with aftermarket wheels w/less backspacing at 100K miles, yeah... My guess is your bearings are going out, just make sure to replace both.