Stearing Issue with Falken Wildpeak Load E Tires

Hi there, long-time reader, first-time poster.

I have spent many evenings reading about similar issues on here--the closest I could find to my setup/issue was Flo Tacos post on the steering thread a few years ago. Basically I've had numerous issues with this setup starting with the balance on these Falken tires. Now my issue seems to be a bump stearing where the stearing jumps all over the road at speeds above 50 MPH. Things I've replaced within the last year for this and maintenance reasons include:

Front bearings/hub, CV axles, front differential seals (ECGS spindle bearing delete), brake rotors/calipers/pads, inner/outer tie rod ends, upper intermediate steering shaft (with a rag joint that had 100k miles on it), passenger side LCA, driver LCA/ball joint is still in good shape.

Some people want to point to the tires being heavier than recommended for Tacomas or the fact that I don't have a sway bar and I'm open to any and all suggestions. I've checked everything and it feels tight. Was going to replace the steering rack bushings but they seem to be in good shape. The truck is a 2013 with 290,000 miles.

Thanks for your help!

 

Try rotating your tires from front to rear.

Put the sway bar back on.

What spring rate are the front coils?

Got any photos of the truck/suspension/steering rack?

 

Do you happen to have your alignment #?

 

Are the alignment cams at 100 lb/ft?

What's the tire pressure?

 

Yeah, they're at:
3.77 degrees Left, 3.59 degrees Right -- Positive camber
.24 Left, .29 Right -- Caster
.07 Left, .08 Right -- Toe

I will check that. Have the SPC cam tabs/bolts.

Tire pressure is 42 in the back, 38 front.

 

Yeah, working on the sway bar. I deleted it semi-permanently, like an idiot.

I believe the springs are the 600 lb but I need to confirm.

Will try to post some pictures tomorrow.

 

Any weight in the bed? That's pretty high tire pressure. Try airing down to around 30-32 and see if it helps

 

You have caster and camber reversed. But they look good.

Has anyone checked the lower ball joints properly? are they original? Steering rack?

 

I contacted Falken and that's what they recommended based on the factory numbers. Yeah, haven't figured out these tires yet so I'll try airing down. Do typically have some weight in the back with a topper and tools. Front Prinsu access cab rack but no armor, bumpers, winches, etc up front.

Ball joints are good. I forgot to mention I replaced the passenger LCA but not the driver side. Ball joints seem solid. Steering rack bushings are old but firm. No play really. I plan to replace them because of age. Also, I replaced the upper intermediate shaft with the rag joint but the one I put in has about 100k miles on it. Definitely helped to stiffen up the steering a bit but the bump steer seems to be a separate issue?

 

E rated tires are for full size pickups. They will only cause your taco to ride rougher and behave worse on the road, that pressure it too high also, 35 psi is good. Sounds like you’ve got a few things combining and causing a noticeable issue

 

What is the offset of your wheels? Are you running wheel spacers? Both these can lead to bump steer.

 

Having just gone from P rated Toyo AT3s to Motomaster in LT rated, ride is def harsher over bumps, but my truck is pretty smooth on the highway. Also E rated tires need much higher air pressure to cary the same load as P rated. I believe 40psi is the minimum for our trucks. Based on most of the forum comments around tire PSI, I suspect there are a lot of people driving around on under inflated LT tires...

 

Drop E rated PSI to 32-35. That's as good as your E load tires will get.

I'd bet it's mostly the front shocks are just tuned to be too sporty. How much lift/preload on the coilovers? Could try turning the DSCs all the way down soft to experiment. Mine were a bit like that before breaking in and dialing down the DSCs. I still need to revalve mine to be optimal.

 

I've been running e tires on my truck since I bought it I have 32 psi in them and no issues.

 

42 psi

 

Offset:0mm
Backspacing:4.750
No spacers

 

I have the high speed dialed all the way down and the preload is set to stock height for the Fox shock. Firmer valving feels more solid at speed but the issue seems to be coming from something in the steering wheel/rack because I feel every bump jerking the wheel as the road irregularities are being transmitted up from the tires. Do people that run the load E tires change anything with the steering rack/column?

Looks like Falken was wrong for PSI, I ran the numbers through that calculator and should be at 35 for front, 36 for rear. I'll dial in these adjustments and report back.

Thanks you all. Got some more things to try.

 

Try setting the tires down to 30-32. Seriously it's not going to hurt anything. Part of the benefit of 10 ply tires is you can air them way down and they'll be fine

 

I can't agree with this enough.

 

Your tires being load range E is not your problem.