Transmission issue?

[ProjectWolf]

I have had this issue happen twice, and then disappear for a while. Anyone else?

I work in construction in a very wet area, so I occasionally have to use 4wd in the mud to get around my jobsite. I use 4wd auto, and she does just fine. Never had to get pulled out. The issue is, randomly after putting her back in 2wd, she will drive fine and shift fine.... except when I try to out her in park.... no. Check engine light comes on, dash says not in park, and wont turn off. The first time it went off, check engine light disappeared after a few minutes.
This last time, I legit couldn't get it to do anything for a while. I ended up shifting it back to 4wd, back to 2wd, a few times before I heard a clunk and it let me turn the truck off. Had to drive back to work with the check engine light on for a bit, but when I went back later in the day... no light, no issue.

Is this just my truck needing the trans fluid changed? 94k miles on her. Its due for an oil change soon, just had water pump replaced.

 

[Lyle Longboat]

Can/did you check your trans fluid level and colour? I’d start there first. Same thing happened to me, but without using the 4WD. It’s delayed shifting and when my
Trans started to go, that was the first thing that happened to mine. Try to move from
Park to drive and it would take at least 5 seconds after I shifted for it to engage. Sometimes I’d have to shift back to park and then try it again in order for the truck to shift.
That’s my own thoughts, however there may be others that have more info on this issue your having. Oh, I didn’t have any check engine lights On when the is started happening to me.