Shake/hop from rear at 42-55 mph (SOLVED)

My truck is a 14 DCSB 5100s @ 1.75” and 1.5” toytec aal. Currently at 97k miles and I’ve been chasing this for a while now. It started when I got new tires The tires are for sure balanced (had the shop check it twice) I have check the center carrier bushing and done the drop kit, it seemed to do nothing.

here’s the screwy part.
It’s at precisely 42mph
It seems to be worse with my hitch rack and mountain bike on the back, BUTTTTT with my hitch rack and yz250 dirtbike it all but goes away!
It’s not dependent on what gear I drive in, 4 or D
And it’s not dependent on the load on the powertrain (not worse going up, down, or flat

I’m lost.

EDIT (10/11/20) swapped the wheels and tires between my wife’s 2020 4 runner and it is the issue. So I will try a different set of tires.

EDIT (11/28/20) ordered plastic hub centric rings 108-106mm and it somewhat solved the problem. The only thing I can think of is that I removed the center caps of the wheels and that small difference was enough to make the difference and the rings made that back up.

EDIT (8/5/21) still having the issue. Been running the trd trail wheels off my wife’s 4 runner for a few days and I decided to dump my pro comp 7005 wheels and BFG KO2 tires and Ordered some FN FX pro wheels and toyo open country at3 tires with new TPMS. I’m convinced the pro comp wheels are hot garbage and have been the problem the whole time and the only constant through the entire issues life. Will post final finding when new tire/wheel set up arrives

EDIT (8/14/21) FINALLY SOLVED 100% it was the wheels they were pro comp 7005 they were the only constant thing with the vibe. So changing all those parts was useless but I guess you win some and you lose some.

 

You say it started when you got new tires. There is the biggest clue. If it didn’t exist prior to the tires seems like that’s where you need to start.

 

AALs l I've heard can sometimes change the driveshaft angle, it should be easy to measure. It is possible you could be getting some axle wrap. Check YouTube how to properly measure that.

 

Rotate tires front to rear and see if there is a change.

 

That's easier, do that first.

 

The other thing is it always stays as a vibe of sorts in the back even after I rotate as well

 

Can you stick those tires on another car? I'm just spitting ideas about tires. Could be bad batch, my dad had something like that before, except it was 57mph.

 

Where the tires road force balanced?

 

Yes I could try them on my wife’s 4 runner

 

I’m not 100% sure about that.

 

Having myself spent a few years working for a large chain tire shop I feel confident saying that if your tire/wheel assembly is on the large side, if the face of the wheel is recessed significantly (preventing tape weights from being applied in a dynamic way), if the shop is busy, yeah, you may still have completely imbalanced wheels.

Could yuh take a picture showing the weights on the wheels? I'd like to see how much weight they loaded on and if it's on both the inboard and outboard side.. If you're within 30 days of purchase you may be able to return them claiming a complaint of ride quality.

 

I would buy a cheap set of stock take offs, and put them on your truck and go for a drive. If you don’t have the vibes, you’ve found your problem.

 

Completely different rear suspension. Different weight etc. No need to do this.

 

He could take the wheels from the 4runner and try them on his Tacoma though.

 

Yes. That he could do.

 

To clarify on the request for a pic, I sure as heck can't tell if they're balanced by looking at the weights, but if there's a bunch of them, if they're all in one place or stacked on top of each other/just on one side.

 

I will check out the weights when I get a chance. But I know the weights were put in 2 different spots. Like toward the inside and also towards the wheel face. My uncle works at a Toyota dealership and he is the one that mounted and balanced initially and then checked a second time and said they were perfect. I just don’t get how even after rotation the symptoms stay the same.

could a u joint cause this to happen ?

 

I could try. Not sure how stoked she’s going to be about me stealing the wheels off it with only 300 miles on it though

 

Yes , a seized universal joint could cause this . Have youy been greasing them every 5 K or at every oil change ?

https://www.tacomaworld.com/threads/vibration-diagnostics-for-all-tacomas-write-up.520607/

 

That’s a big negative on every 5k. Looks like I have a project to do.