4A/4H pulls to the left when accelerating

[tomolesnevich]

I am the OP and yes, I eventually figured it out on my own after Ford gave it back to be saying it must be a tire balancing issue. Discount Tire put 2 load range C and 2 E on! They ended up replacing the entire set and gave me a credit towards a future purchase. And the funny thing is I checked one tire after the purchase and it was a C, like I had ordered. Definitely going to check all of them next time.

Thanks for following up on this w/ your solution. I just went through the same issue and this post helped me out immeasurably.

Two months ago I bought a '20 Gold Certified CPO 802a that did the exact same thing. It would pull violently in one direction when in 4A/4H/4L. So, I replaced both front IWE's, no help. Truck still pulled to the left (in my case). Then I bought and installed RCV's IWE eliminator. No help either, but that's fine (i'm never going back to IWE's). Checked the load ratings on all of the tires and sure enough, the dealer replaced 3/4 tires with E load range KO2's prior to sale. One of the front tires that wasn't replaced was C load range. Given that there's ~15lbs of difference between the two tires, no wonder the diff was going bonkers, it sensed a higher load on one side and went to work.

So I put 2 new E range KO2's up front, and no more violent pull. 4A/4H/4L are now all fully functional. (And I figure I can, through judicious use of the loud pedal, even out the tiny wear differences between tires.)

Honestly, can't thank you enough - saved me a ton of time and headache.