SO what causes that wheel shimmy/bumpsteer after installing bigger tires?

I was just curious. I have always lifted and put larger tires on vehicles at the same time. Or lifted it first, tires second. Taco is different. I got 285/75 KM2's and it feels like Im driving a lifted truck. What will fix this? Are the stock billies not beefy enough for the heavier tires? Is the alignment off? Changing tires shouldn't mess with alignment . . . I have less than 30k and don't hit curbs.

I have been told its because the truck needs different alignment specs and I need UCA's to get it within spec. That sounds strange because I am on stock suspension.

 

Bigger, heavier, knobier tires makes the steering shimmy. Probably not balanced 100% right

 

My question is what makes it shimmy? Raptor comes with 35's and Im sure it doesn't shimmy. Does the heavier weight overpower the dampening effect of the shocks? Or is it purely the E rating? My work truck has 11R22.5's load range G and weigh over 100 lbs. They don't even balance them when they change the tires. Those don't shimmy on the same streets.

As I modify this truck I want to make it drive better not worse wherever I can. Girlfriend says it drives rough so I told her I could get some new suspension and it should fix that. I don't want to spend $4k and have it feel the same.

 

The wider the tire the worse it gets. 265’s and 255’s don’t do this. 33” comes in more than one width

 

your not alone i been wondering same thing on tacomas have 2 of them both started it when i moved to larger tires been rebalanced checked all suspension parts still does it the one is a 18 tacoma put bigger tires on it next day after i bought it bingo wheel shimmy only had 88 miles on it

 

have 265/70/17 and they shimmy

 

Sounds like alignment or wheels. I’ve never had shimmy with any of my 265’s or 255’s. Could also be aftermarket wheels if they aren’t Toyota wheels

Tacomas are picky and not all wheels are created equal.

 

Did you change to rims with more offset or add wheel spacers?

 

Has to do with leverage. You mention the raptors having 35” tires. The suspension was designed to work with that tire. On the tacos the suspension was designed to work with a much smaller tire. Look at the size difference of the shocks, UCAs, bolts, mounting points, etc. it’s possible to beef up the suspension and make it stable again with over sized tires.

 

Our trucks are rated for C tires, anything heavier/bigger will cause issues as the truck wasn’t manufactured to handle such. It’s also a midsize truck so any changes like that will affect it one way or another. The raptor comes with 35’s because it was designed to have them from factory, and it also has long travel suspension from factory.

Any modification you do to your truck you might have to modify something else in order to fix it you’ll find.

 

Well, you 'kinda' are. You are now lifted the value of the radius increase over the tires you replaced.

I agree with you. Not sure your source for this info is to be trusted for additional advice.

Side note. Tires/wheels having nothing to do with the alignment process, they are just the 'beneficiary' of it. The hubs are what's actually being aligned.

 

can’t really compare a super beefy factory designed truck with 35’s to our flimsy factory shit. fuck even the alignment tabs are about fucked after the first alignment on many trucks.

 

ray 10's

 

that's kind of my point. what gets beefed up to keep wheel shimmy down?

 

that's what I know to be true as well. but you always hear get an alignment with new tires. Im assuming its just to make more money off you. or if your wheels wore prematurely from misalignment in the first place.

 

that's what Im looking for. Im wondering if new shocks will eliminate shimmy. my buddy has 275/70 k02s on adjustable billies and he wobbles too. And I am told those are beefier than stock. as far as UCA's Im assuming aftermarket ones are there to allow proper alignment when ride height is lifted.

 

The heavier the the tire/wheel the more damping it needs to cope
Tacoma ≠ Raptor

 

everything. it weights about 2000lbs more. the tacoma was never intended to have 11-12.50” wide 75lbs tires w/ offsets at or below zero.

 

Potholes and the stress of driving can knock the alignment out. The new tire alignment is a precautionary method. It really would suck to spend $$$ on tires only to have them wear out in 5k miles due to a bad alignment caused by the previous 50k miles of potholes you hit.

 

I guess Ill see if its in spec. Im assuming it is though.