What exactly does Sport Mode do?

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ryoung57

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Is the rear locking differential button on? It sounds terrible when that is on and you are turning. My dog steps on that one every once in a while

No. But what I’m experiencing is similar, just not as extreme as when the diff is locked.
 
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ryoung57

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Something of note to add: it seems to do it more consistently when going up an incline. This could be due to the increased load, although I’d think that could be duplicated with more throttle on flat ground, or it might mean that the fluid is low so when going uphill something important isn’t getting the lubrication it requires.
 

bmpcamry09

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Get the rear diff checked out. Drain the fluid and check for quality and color or shavings. Check your u joints on all your drive shafts as well. Sometimes if those are binding it will cause similar issues. While your at it, make sure your front axle hubs are disconnecting properly when in 2H.
 
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ryoung57

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Get the rear diff checked out. Drain the fluid and check for quality and color or shavings. Check your u joints on all your drive shafts as well. Sometimes if those are binding it will cause similar issues. While your at it, make sure your front axle hubs are disconnecting properly when in 2H.


I planned on pulling it into the shop and looking it over really closely underneath today when I changed out my lug nuts. Unfortunately I ordered the wrong ones, so hopefully tomorrow or Monday.
 
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ryoung57

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I’m still at a loss as to what’s going on here. It may be trans, it may be diff, it may be an axle, it may be a blown shock, it may be brakes. It’s probably a combination. After I left a stanky review with ford on the purchase, the dealer got way more motivated to fix the issue. They drove a loaner up to me and took mine back to check it over. I can say for sure, my truck is not “right”. The 21 301A they gave me as a loaner is much more basic with 20in wheels and regular suspension, but it is MUCH smoother to drive. No trans jerking, no vibration in turns, no kick in the foot when downshifting on the brakes.
 

19ExpMaxPlatYYC

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Perhaps you're jerking it around and hitting it hard enough that the 4wd is turning on to provide more grip. It will argue a bit on dry pavement asentioned above.
 

LegalBrief

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Correct no 4H on dry pavement, 4H or 4L will destroy tires and possibly front drive shaft, 4A is fine on dry pavement - to save fuel I only run 4A once it’s wet
 

ROBERT BONNER

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I'll start by saying, I have no idea whether S mode tightens the elsd on launch; it might. But, I was chirping the left rear at one point while in S and making quick left hand turns....Shortly after experiencing it a few times, I noticed my right rear shock had blown out. In retrospect I was getting more lean on quick lefts than I was on quick rights (even with the Hellwig rear sway bar). I replaced the rear shocks with Bilstein 5100's and haven't chirped a tire yet under the same conditions at the same corners.
 

Left Coast Geek

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I mostly only use 4A on surfaces like wet grass or dirt at very low speeds when towing... Like entering or leaving a campground....
 
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ryoung57

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Update. Problem seems to be solved. The selling dealership put a new transfer case clutch in it (messing up the gasket in the process) and it still shook. My local dealership put an all new transfer case in it and changed out the IWE on the drivers side hub. It wasn't as bad, but still didn't feel right. I lifted the truck and crawled under when running to check to see if the hubs were disengaging in 2H - they were not. I dropped if off at the dealer and after a whole day of messing with it, they "couldn't replicate the problem" (morons didn't even understand how the IWE system works). So I had to do it myself. Ten minutes with my mighty vac to see where I had and didn't have vacuum led me to the IWE solenoid on the firewall. I'd been driving around for the last year with the hubs locked in. $40 and 2 minutes of work later and it's perfectly smooth.
 
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