4x4 switching

Hey guys
Just bought a used TRD 2016 with 60k km on It .
I have a question here
Switching from 2wd to 4x4 there's no issues and can do it up to 90km/h
But when switching back it won't switch unless I pin it a little.
I've tried under 40km/h. Tried doing neutral. Tried releasing the gas or just keeping normal foot petal pressure for maintaining speed. No matter what it won't switch unless I give it quite abit of gas.

Any ideas? Could my solinoid switching be weak?
Dealer is telling me because I have one duratrac with brand new thread on my back passenger side it won't spin at the same speed as my other tires that are at 80% tread. Since they aren't all spinning at same speed it won't switch.

 

The dealers idea sounds plausible, there could be just enough binding in the drive line that isn't allowing the system to disengage. Sometimes I'll need to saw the steering wheel slightly to get mine to engage/disengage, and it gets plenty of use. Things need to line up enough to mesh, and that may require some "english".

 

My only fear is I'm doing 1500 km a week. And I have about 35k km on my power train left .
Just making sure she isn't messed up haha

 

If it won't switch back in neutral something is wrong. If literally the only way it goes back to 2wd is by acceleration, something is wrong.

But as said above, the dealers theory isn't crazy.

 

I'm assuming you were stopped when trying it in neutral? Mine usually won't engage/disengage until I put it in gear and sometimes touch the gas/release brake (I only switch when stopped).

 

Change out the fluid. Use 75w. If anyone put the 75-90 or any othe gear oil, it will not function properly. 14 and up have a different transfer case and it’s common people put the previous gen oil spec in it. I know because I did it and had the same symptoms you are having.

 

Sometimes it may not even shift in neutral, you have to move the vehicle just slightly, and "snick", in it goes. Like I mentioned, things need to line up to mesh.

 

Yep, this. I don't really think you necessarily have a problem OP.

 

I still suggest changing the fluid. It’s about due anyways if it hasn’t been done. And if it has, it’s a very high likelihood they put the wrong stuff in there. I’ve heard a few times on this forum about the techs at the dealership only carrying axle fluid and insisting that it’s fine. Which it’s not!

 

Now that mine is a couple years old it shifts was quicker. Maybe yours just hasn't been engaged enough. Toyota recommends at least 10 miles per month in 4wd. Wheel speeds do have to match before engaging or disengaging.

 

Thanks for the info. Is this different oil than what's in the diff?

 

Yes they changed the transfer case when the body style changed. To make sure which one you have, the new style has 1/2” drive pipe plugs for drain and refill as apposed to bolts with crush washers. Check your owners manual to be certain. Front and rear diffs take the standard gear oil as they always have but the new transfer cases take 75w Toyoya gear oil. The stuff is really expensive. It’s controversial over whether we can use a different brand. There are only two other brands available and unknown if they are completely compatible. Ravenol and Redline. I’m using Ravenol with no issues. Everything smooth as silk so far.

 

Okay so here's where I'm at . There's no maintenance done on it . So it's the stock oil . It's due for a change in 5k km
That's said we drove the truck . My tire tread is driver side 10 driver back 10 passenger just under 10 and back one is new at 14

We notice on the PC that the new tire is spinning at 1-2km difference vs the other tires.

If I pin it again it will switch.

They are trying to blame the tire but I still think it's a weak sensor/solinoid

I could maybe see the tires on a AWD vehicle. Especially as it's hard on the system when tires don't match.

Thoughts?

 

Need new tire to match the other newer tire. 1-2 km is a huge disparity. You are suppose to change tires in pairs anyway.

 

A big smoky pegleg burn out might help. wear that tire down to 10.

I still suggest swapping the fluid in the T-case. Also it’s an open differential, if the larger tire is in the back I don’t see how the transfer case would know unless it somehow reads the different mph and decides on its own when it’s going to shift.

The tires are supposed to be changed in pairs for good measure. Also, ust because there are no records of maintenance being done on the t-case doesn’t mean the owner didn’t do it.

 

Well now I know . I found one that will match the 10/32 tread . So we are good to go.

 

Why don't you throw the new tire on the rear then try it. I'm assuming the dealers theory would only apply to the size difference being in the front for it to disengage.