Help please! Shaking issue!!

First off I have a 2006 tacoma 2.7 auto rwd. The issue is I'm experiencing a shake in the back, sometimes in the steering and in the seat. It's intermittent and it's not a violent shake more like a shimmy. Happens after 55mph. I started to experience it when I put in a new truetrac auto locking diff and put on some negative offset tires. The lunchbox locker was put in by a shop and I put the carrier in. I have had the truck at the shop to road force balance the tires already 4 TIMES. Mechanics looked over all my suspension components and being the truck has 40 xxx miles everything is tight. They said they have no idea and don't know what it is. I put on another set of rims and tires and it was a lot better but it still experienced the intermittent shimmy. I am at wits end I don't know what to look for anymore.
Please help!!!

 

You said that you installed a set of neg Offset tires ( I assume wheels as tires do not have an offset ). And you said that you also tried a different set of Wheels and it got better, but it was still present.

Are any of these wheels Genuine Toyota Wheels?
Are they Hub centric or Lug Centric wheels?

Toyota's are very sensitive on the Hub Centric issue. That is how I am reading your problem. What you need if you are using Lug Centric Wheels would be Hub Centric Adapter Rings to compensate.

http://www.hubcentric-rings.com/why_hub_centric_rings/?confirm-international=true

https://www.motorsport-tech.com/hub_rings.html

There are other issues that could cause a shake such as you described, The Center bearing on the drive shaft and or Universal joints come to mind... Check those as well.

 

I put on American racing Baja 15" alloys. I put on different rims and tires with a similar as stock size and offset and problem still arose. U joints are fine and bearing is fine.

 

From what I see Googling those wheels:

You probably need the correct size Hub Rings as I stated above.... You need to find the Hub Diameter measurement of the wheel and get the appropriate adapter ring to fill the gap between the wheel hub hole and the actual hub size of the axle hub.

I'm pretty sure the stock Hub is 106 mm. What size is the hub ceter hole in the wheels you have? Get the rings that match the difference.

 

I have tried stock rims problem still exists. Not as pronounced because my rims and tires and larger and more aggressive but it's still there.

Also went to Toyota and they did the whole well good luck.

 

Get them road force balanced and make sure they use the Haweka Adapter.

 

Also when driving on a colder brisk morning all seems well, I also dropped my Carrier a little and seemed to do something different. A little better I guess.

 

Changed rear u joint one of the cups was toast... Problem still present

 

I don't exactly have a puller to swap out my trutrac diff with my stock one so no.

 

It's my daily so kind of plucking away at troubleshooting

 

Put on stock rear tires and rims... So other than stock I got aal on the back... Still vibrates...

 

New u joints checked carrier bearing... Intermittent vibration still present... Selling the truck. Toyota Canada told me basically to f@$& off toyota dealer is bunch of kids working and transmission and driveline place has no idea.

 

So you have more than one thing happening which sucks because the lug centric wheels without a ring were almost certainly a contributer.

 

Final attempt the driveshaft is going in to get balanced

 

I'm having a similar issue as the OP, minus the lift and rear diff switch. Mine is a 2010 AC RWD. I bought the truck used with Ultra Maverick wheels. The shake problem started when I had the wheels rotated. Went back and had them rebalanced and it help very little. Went to a different shop and rebalanced, 1 wheel out .25 and 1 out .75, not much.

They recommended lug centric lug nuts so I bought them and they helped, but that little bit of vibration is still there. So today I ordered hub centric rings. Not a stock size, which means custom price, but if this fixes things so be it.

I'll report my findings, maybe it will help the OP.

 

Just acquired a driveshaft for 40 bucks so well pick the best pieces of both evils will report more. @CurtB let's find this problem!

 

Have the exact same problem. Truck is bone stock other than trd exhaust. 47k miles on the truck, but been dealing with it since my first tire rotation. Since then I've purchased new tires after multiple balances. Recently bought a set of take off rims and had those mounted, no change.
Took it to discount tires and they rotated the tire on the rim to see if that helps. Weird thing is it's only when one of the two specific tires are on the front. It can be either one or both, but if they are in the back the truck rides great.

 

@CurtB which lug centric nuts did you buy..? @HXC same issue here. Front was shaking put those rims and tires to back and now front is fine 95% of time.

 

The lug nuts were supplied by the tire shop, so no idea who made them.

 

Can you show me a picture of them @CurtB