2018 5.0. I'm having a recent issue where upon cold start and placing in reverse the transmission is not fully engaging as normal. Basically the truck starts moving backwards but with huge slip. After about 10-15 seconds the problem corrects and reverse fully engages as normal. Subsequent shifting to reverse is fine until the next cold start. No codes or other indications.
Anyone have this issue before? My first guess is that a valve internally is leaking and leading up to a delay building clutch pressure on a cold start.

 

Sounds like a trip to the dealer is in order.

 

I am new to Ford but I have noticed this as well. It isn't a when cold issue that I have noticed. I tend to back into my garage and I pull up, stop , shift to R and it seems like I sit there for about 5 sec before it actually shifts to R and I can back up.

I have an '18 but the 3.5EB.

 

There is a delay shifting from Reverse to drive, and opposite. If the delay is unacceptable, have it investigated. Until you are able to drive 2 more vehicles that do not feel like yours, the situation will be treated as "operating as intended".

The 2016 6-speed I have shows less delay when shifting from neutral to drive. I can remove it from reverse, coast for a moment (because that is my driving habit) and shift to D and it's nearly instantaneous.
It is similar shifting into reverse.

Sennister, if you have a literal 5 second delay, that's too long. Take a breath, count to 5 and imagine how much life passes. We don't expect you to be sitting in traffic that long. I can coast a long way in 5 seconds.

 

Try resetting the KAM and Trans to re learn

 

This is definitely not the normal reverse time delay. That delay is actually variable based on things like trans temp. This is a case where the tranny is going into reverse, however, the clutches aren't fully engaging. Preliminary assessment is that the trans pump is losing prime. Will be testing with cold start and drive to see if it is both ways. I'm betting it is. Spoke to the top trans expert I know (my brother) and he's betting I'm about to spend some time at the dealership.

Upcoming tests will be:
Cold start and immediate to drive to try and duplicate forward.
Cold start and wait 30 seconds before putting into reverse. Depending on result also try in drive.
Test after 4, 8, 12, etc. hours to see just how much down time causes the issue.

Looks like I'll end up taking the results to the dealer for some warranty work, so hoping to save a week of troubleshooting with some data.

 

Mine is doing this in forward and in reverse when not driven for a day or two.

 

Seems to be a Ford thing. My 2016 has the delay and it’s most noticeable going from drive to reverse and the same with my Dad’s old Ranger. My Aunt had a 1980 something Grand Marquis and it did the same thing. But not 10-15 seconds, just a few seconds.

 

The 6 speeds in my 2011 and 2014 also had a slight delay.

 

I have a 2015 Mustang and a 2018 F150 both 5.0. I believe it is as simple as the torque converter filling completely after sitting. Mine only do it after setting for a few days. I could be wrong but that is my guess.