2017 TRD Off Road won't engage 4Lo or lock rear diff

My buddy has a '17 Off Road MT 4x4.
It's only engaged 4Lo once and won't lock in the rear diff at all.

He's tried it completely stopped, then slowly rocking forward and back, level ground... nothing.

Diff won't engage either.

Any thoughts?

 

Not so sure about your 4LO problem. If its engaged in 4HI and in neutral, I've generally never had a problem with it switching in to 4LO.

The rear diff will only engage in 4LO, so if you aren't able to get in 4LO then it will never engage unless you've done some sort of mod to it. In the past, to get the diff to lock I've had to turn the steering wheel hard left or right to get the tires spinning at different rates. This will sometimes help it lock.

Is the truck beeping at him when he's trying to engage 4LO?

 

Yeah, I realize that its not going to diff lock unless it goes 4Lo first. The rig does beep, light flashes but never fully engages. You can feel that it's not engaged either, just sitting in 4hi

 

Manual or auto transmission?

 

So he tells his buddy to post on an online forum rather than read the manual... seems inefficient

 

Or go to a dealer with a pretty much new truck

 

Manual

Nope... he didn't ask me to reach out. I decided to see if anyone here has had a similar experience. Don't know if you ever read the manual, but its not much of a troubleshoot guide. Ya try what it says and doesn't work. So I guess reaching out to a forum full of owners is just crazy...

That will be done as well, but if someone had an idea of what it might be without the hassle of the dealership, that would have been great.

 

Had the same problem. Tell him to push his foot all the way through the floor board on the clutch. The switch has to be all the way depressed before it will even think about engaging.

 

Thank you, I'll mention it just in case

 

The only reason its ever beeped for me in my 2011 is because I was either rolling or not pressing the clutch all the way. Let us know if it works for him.

 

Yep, the clutch safety switch needs to be engaged to switch into 4lo. Most manuals the switch is basically all the way to the floor, it always annoyed me I had to go that far so I put a felt pad on the backing plate that comes in contact with the switch and taped it up with electrical tape to keep it in place. This allows me to push it down about 90% before the truck starts or kicks into 4lo

 

Just to be safe, for the rear diff, tell him to try engaging it and slowly turn. If it's not lined up, going forward and backwards only wont line them up. After getting it into 4lo of course.

 

Thank you, I will have him try to make sure he is fully to the floor.

Awesome, thank you

 

Did the dealer find the issue? I have the same problem only for the diff lock not engaging, everything else works

 

I now am having this same issue. Any updates?

 

Wow 2nd time this thread has been woken from the dead. Like posted above push the clutch all the way. Like through the floor all the way before you shift to 4lo.

 

Oh sorry, didn't specify. 4 lo engages fine. Rear diff isn't locking once I'm in 4 lo

 

Start driving and turn the wheel some.

 

Tried it on a dirt road for about 10-15 min while in 4LO. Left, right, left right. Just kept blinking

 

Try driving in wide circles in a parking lot then. Once it engages, drive straight and unlock it.