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.

 

[Hal993]

For anyone struggling with this and finding this thread. I can confirm for 2024 that the tire weight mismatch IS a cause of this behavior.

One year ago, "Tire Shop" told me I had (2) tires that would not balance and were bad (they were). "Tire Shop" mistakenly sold me (2) E rated tires... and installed them - without me every knowing... they never checked that they were replacing C rated tires.

Fast forward, "Tire Shop" rotated the tires incorrectly - which (happenstance) resulted in me having one E rated and one C rated tire on each axle.

... but I didn't know.

The truck started pulling HARD to the left in 4A... it was a dangerous, unusable state. I took it in to Ford - they looked and looked... and couldn't find anything wrong - told me it was fixed... it wasn't. I took it back, they looked and looked again - swapped tires... and it pulled hard right.

Ford told me I had a bad tire - to deal with the tire shop. I found this thread... and went and looked at the truck. Holy crap.

"Tire Shop" volunteered to do the right thing and replaced (1 year later) the 2 E-rated tires with C-rated tires today. The truck dries like a dream... a little torque steer in 4A... but as it should be!