4hi question

So looking on where to start troubleshooting with 4hi.

So issue is truck will not Disengage out of 4hi when driving, will shift into 4hi quick and easy. Same with 4lo no issues getting into, but coming out of 4hi when driving I can not get it to Disengage, I have to come to a stop and put it in either natural or reverse and it will pop out. Sometimes I can get it to Disengage when making a hard turn either left or right.

I have tried being off the throttle, on the brakes, off the brakes, slow coast in neutral but nothing seems to help unless I stop.

Not sure if it's a binding issue or an actuator issue but it use to shift in and out of 4 hi in the past with no issues. I've been under the truck when it's engaging and Disengaging and the transfer case actuator sounds normal but the front diff one is louder then the t case. No grinding or popping just loud electric motor sound.

Also use it often, in either snow, sand or mud up here in the PNW. Never goes more the 2 month without being put into 4x4.

 

Does it beep at you when you try to switch back to 2wd?

 

Nope just flashes.

 

Ever change the front diff and transfer case fluids?

 

Yup did a fluid change front, rear, and t case around 40k

At 53k right now.

 

What transfer case fluid did you use?

 

Valvoline

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90

 

x2 liters. https://www.blauparts.com/ravenol-m...ZmHbv2SuUyc_72C3ziUsgkKB4I5cfumRoC3wIQAvD_BwE

 

Spec is straight 75W. Maybe swap it and see if that helps.

 

I’ve had great luck with Ravenol 75W in my 2016 transfer case. Even in this crazy cold weather, quick engage/disengage.

 

I start with trying 75w to start. Toyota part number is

$96 08885-81080 Toyota Genuine Transfer Case Gear Oil LF 75W 1 Litre 08885-81080

08885-81080.

 

My first thought was wrong spec fluid. It wants that straight 75w. 75w90 is 3-4x as thick at operating temperature. The spec changed in 2014? when they when to a different transfer case.

When I first got my LX, it would throw dash lights every time I tried to engage or disengage the center diff lock or low range. I changed the TC oil and started exercising both daily after driving my kids to school so the entire system was warmed up. Did that every day for a week, and it has had no problems since.

 

Change out to 75W. 75-90 is too heavy for TC.

 

I'll give the 75w oil a shot and see how that goes. Now just have to wait on shipping.

 

I used Ravenol 75W in my transfer case and now it shifts alot faster

 

I have a good friend that’s parts manager at a Toyota dealership. He said that the only time they use 75w is if it is a warranty issue. Otherwise it’s 75-90w. I called a couple other dealers service departments and asked for a price and what they use for fluid they told me 75-90 in tc, and front and rear. I change mine out and used 75-90 synthetic in them 20,000 miles ago and everything works as it should. Thought I would Pryor know my experience.

 

So changed the fluid to 75w and still having the same issue. Did alittle more troubleshooting while driving. In park I can shift it into and out of 4hi without any issue. But once I start driving I can only get it to come out of 4hi if I turn the steering wheel about 270-360 degrees it will Disengage. So seems like probably a binding issue. But not sure how to exactly pin point it to that. Anyone have any ideas where to start or more troubleshooting ideas?

 

Have you looked at the differential or xfer case actuators?

 

That's also my next thing to check out. Trying to decide if I want to pop them open and make sure they don't have dirt or corrosion in them. Or if I want to completely take them off to look them over.