Issue with disengaging 4W LOW

I've had my 2016 Tundra since Fall of 2015. 4W drive both in 4W HI and LOW worked flawlessly until last Fall (fall of 2024). Last fall after 4Wheeling into remote backcountry locations (here in Colorado guiding fly fishing and elk hunts) on high clearance forest roads (so 4W LOW range is a must given tough terrain), I began to have issues with getting my Tundra out of 4W LOW! It would take significant attempts of backing up or going forward short distances, putting the truck in neutral before it would disengage. Meanwhile 4W HI, no issue at all works fine.

I brought my Tundra into my local dealer and they told me I needed to replace the transfer case actuator and the front differential actuator which I trusted them and had it done, total cost $4516!

After this, I of course tested briefly at home and it seemed to work great! I went through winter without using 4W LOW and then late spring after wheeling into the Lodge where I guide fishing (8 miles of high clearance terrain, no more the 10MPH and steep sections too) I tried to take my truck out of 4W LOW and same problem surfaces, it won't disengage!!! I wrestled with this 2 more trips this summer (used my other truck in between many times in between Tundra traveled trips) and most recently Labor Day. I then took my truck back to Toyota and they tell me all works fine, no issues. If you simply put the truck in 4W LOW and immediately then take it out, it works as it should. I told them you need to drive for a while and then the problem surfaces. They claim to have taken it 4Wheeling and said it works. I am 100% confident the first time I take the truck back to the mountains I will encounter the same problem! Toyota also said I shouldn't be driving my truck 8 miles in 4W LOW which is nonsense! I work in the backcountry in tough terrain and that's why I have a 4" lift and 34" tires on my truck. One last comment 4W HI continues to work just fine.

I've read a lot of similar posts on this issue for which I've tried for the most part so thought I'd post to see if anyone has had similar issues and a potential resolution including what I might tell Toyota! Given my continued problem, I can't help but feel I may have paid $4500 for something I didn't need to as the problem still exists! Thoughts? And deeply appreciate your thoughts in advance.

 

A couple of things..

The actuator needs to be exercised regularly. Toyota recommends shifting through 4WD at least once a month and driving 10 miles in 4Hi to keep parts lubricated. I notice that when it’s been a while between shifting in to 4WD, the actuator is slow to respond.

To clarify - you are in Neutral when attempting to shift in and out of 4Lo, yes? You MUST be in Neutral in order to do so. 4Hi can be accessed in gear while driving below 60mph, but 4 Lo has to be stopped in neutral.

What has your maintenance schedule been like for the transfer case and front diff fluid? Every 30k miles is recommended, but sooner wouldn’t hurt seeing as how you are a guide and use it often.

Use a quality synthetic fluid. Straight 75w is recommended for the transfer case but most dealerships and lube shops, as well as DIY’s, use 75w90 because it is less expensive and more readily available. Toyota 75w is something ludicrous like $100/quart. Ravenol and Redline make a suitable replacement for 1/4 of the cost.

The front diff specs 75w85 but similar to the transfer case, many use 75w90 in place of it. If you are having troubles shifting, perhaps try some 75w85.

When I purchased my ‘21 used, I made the dealership include differential and transfer case service before taking possession. They used 75w90 all around. The transfer case had a leak, which was repaired under warranty, and they used 75w90. So just because the work was done at the dealership doesn’t mean they used the recommended fluid - just one that meets a spec (and their budget).

Else, it can be somewhat common to have some difficulty getting in and out 4wd. Good maintenance and regularly exercising the actuators are the best ways to prevent those issues.

One more thing though - as a fishing guide, are you regularly exposing the underbody to a lot of moisture? You can get corrosion in the actuators which can cause them to fail, but typically slow-to-engage is maintenance related.

 

The system has got to be exercised regularly like at least cycled a few times once per month. Read the manual, it's in there

 

$4500 for 2 actuators is robbery. Like criminal activity. Maybe a new transfer case and front diff for $4500, but two electronic actuators? No freakin way.

 

the more I hear about what people pay for service on their Toyotas… it’s a really sad state of the industry.

 

Thank you for all your feedback! I appreciate it. I will engage 4W Low a couple times a month and see if that helps. I do perform the maintenance on the transfer case as required by Toyota. It's frustrating for sure as I take ALL maintenance seriously especially with what I put my truck through where besides off road pulling my horse and mule to / from the mountains a few times a year. It's been an awesome truck until this issue surfaced! Hoping to run it for a while yet as only has 130K and at today's prices plus the off road upgrades I have in, don't want to buy another anytime soon!

 

I have a monthly use it lose it reminder on my calendar. Might be a good idea in Colorado with the wide temperature swings daily.

 

You should be good to go for a while. I've been beating on my '13 since I bought it new with no real issues to speak of. Take care of the maintenance and it will take care of you.

Toyota has two sets of service intervals in the manual - Standard Duty and Severe Duty; 95% of trucks fall in to the Severe Duty category but things like 10k oil changes are touted for the Regular Duty service intervals. I would definitely follow the Severe Duty which recommends more frequent oil changes in all of the drivetrain components. I would also recommend trying 75w oil in the transfer case instead of 75w90. I have a few bottles of Redline 75w waiting to go in to my '21.