Sudden acceleration in LOW 4X4

[SubmarineNuke]

So even at Off-Roadeo I noticed that there's a very big lurch in one of the gear changes, appears to be 2 to 3. You'll be chugging along and then it really hits you as it shifts into 3rd. I said something and even the instructor agreed with me. Perhaps that's the case?

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[dgorsett]

I have experienced something similar in my F250. Only going down hill in first fear low range. engine will throttle up by itself. My assumption has been it's sensing fuel load up (rich burn) and trying to burn off fuel. Oddly, shifting to second gear calms it down.

 

[AK SNO RIDER]

Hi. I have experienced the same thing and posted about it here:

https://www.bronco6g.com/forum/threads/uncommanded-acceleration-in-4l.50421/

Eventual theory was a downshift from 2 to 1 on a 2.7 auto in Normal mode 4L. However, I did have it happen a few times in Rock Crawl last time I was out. Yes, it is a little unsettling.

Interesting, glad to have my experience validated. If it's just a gear shift, guess that's unavoidable. Could be bad though it it launched you over cliff or into a tree!

Yea these transmissions feel super funky when they are shifting in low range. Definitely unsettling but seems to be normal behavior for them.

 

[Ford Motor Company]

Noticed it first time I went off-roading with my new Bronco, but decided it must have been my foot hitting gas and brake pedal at same time. Took a difficult trail yesterday and am near certain that when I experienced it (2wice), my foot was only on the brake, or over brake. Odd sensation as your moving slowly, then you feel the truck accelerate by itself. Could be issue. Curious if anyone else with Wildtrac has experienced? AND JUST TO AVOID THE NEWBIE SCOLDS, I've 30 years of off-roading experience so no rookie issue here.

Back-up camera issue previously sited still constant. Oil change on Friday and hope the dealer has a sw fix.

Finally, not sure the correct tire fitment on OEM Sasquatch. Left some serious scrapes on my pristine black rims, while jeep partner had none. Thinking wider tire to protect rim. Battle scars are inevitable (this was a challenging trail in Rockies), but it's pretty lame to see the scraping done that would not typically impact rim.

Otherwise, STOUT vehicle, definitely more rock crawler than given credit by some with f/r lockers working to perfection. Crab crawl around a turn with tight trees was awesome.

Hey there! I can look into your Bronco’s acceleration concerns on my end if you’d like. Will you send us a private message with your VIN and dealership info?

 

[Jhuff]

I have had a similar experience but in completely different situation; so this is either completely unrelated, or possibly another variable with which to determine cause:

I have a 7MT, and on several occasions while engine braking to a crawl ahead of a red stoplight (in 2-Hi), I get a lurch immediately after downshifting. I cannot recall if it is always the same gear.

I cannot describe it any other way than sudden acceleration, albeit very brief. So brief that I do question whether I am somehow confusing it with the sensation of braking, but I'm 99% sure it's a forward motion.

 

[BigBirdBlackDiamond]

Both my Black Diamond and Wildtrack exhibit this behavior. I am going to start driving in manual shift mode from now on while in 4Lo.

 

[Ford Motor Company]

I have had a similar experience but in completely different situation; so this is either completely unrelated, or possibly another variable with which to determine cause:

I have a 7MT, and on several occasions while engine braking to a crawl ahead of a red stoplight (in 2-Hi), I get a lurch immediately after downshifting. I cannot recall if it is always the same gear.

I cannot describe it any other way than sudden acceleration, albeit very brief. So brief that I do question whether I am somehow confusing it with the sensation of braking, but I'm 99% sure it's a forward motion.

Hello! I would like to look into your acceleration concerns. Can you send us a DM with your VIN and Ford dealer info?

 

[Jhuff]

Hello! I would like to look into your acceleration concerns. Can you send us a DM with your VIN and Ford dealer info?

Thanks, but at the moment, no. I am still not convinced I have a problem, or that I could repeat it for the service guys. I will come back if I come to a concrete conclusion.

At the moment, the only way I can describe it is as an eerie feeling when downshifting to first at slow speeds. Not enough evidence yet to bring to the shop.

 

[Ironiguana]

Noticed it first time I went off-roading with my new Bronco, but decided it must have been my foot hitting gas and brake pedal at same time. Took a difficult trail yesterday and am near certain that when I experienced it (2wice), my foot was only on the brake, or over brake. Odd sensation as your moving slowly, then you feel the truck accelerate by itself. Could be issue. Curious if anyone else with Wildtrac has experienced? AND JUST TO AVOID THE NEWBIE SCOLDS, I've 30 years of off-roading experience so no rookie issue here.

Back-up camera issue previously sited still constant. Oil change on Friday and hope the dealer has a sw fix.

Finally, not sure the correct tire fitment on OEM Sasquatch. Left some serious scrapes on my pristine black rims, while jeep partner had none. Thinking wider tire to protect rim. Battle scars are inevitable (this was a challenging trail in Rockies), but it's pretty lame to see the scraping done that would not typically impact rim.

Otherwise, STOUT vehicle, definitely more rock crawler than given credit by some with f/r lockers working to perfection. Crab crawl around a turn with tight trees was awesome.

Same thing happened to me this past weekend. First time in 4 low. At first I thought I accidently hit the gas but in a 2 hour period it probably happened about 5-6 times. It was unsettling. I have a 2.7 auto.

 

[BigBirdBlackDiamond]

@Ford Motor Company This is happening on every 6th gen automatic I have encountered out on the trails and it warrants looking into.

The conditions under which this behavior happens is while operating in 4Lo, auto shifting, going down a grade using the transmission to hold the vehicles speed down. The transmission appears to be in first gear, then suddenly and dangerously surges forward as if an unwarranted upshift has happened. The brakes have to be quickly applied to regain control of the vehicle. (This has been tested in Normal and Rock Crawl mode on both of my Broncos and a handful of other owners vehicles that I travel with). It also seems to happen at random intervals, but always under the same conditions.

Hope this helps and gives you enough info to try and replicate the condition.

Hello! I would like to look into your acceleration concerns. Can you send us a DM with your VIN and Ford dealer info?

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