How long should it take for 4WD HI to engage?

07 Sr5 4WD 4.0L A/T. I came to this vehicle from a 95 Tacoma V6, M/T, manual T/C & I know the electronic version is slower but really........Whenever I select 4Hi, it seems to take a very long time for the actuator to actually engage. Like minutes as opposed to seconds. (I haven't actually timed it but I can if it will help with the question) To the extent that I frequently no longer need 4WD by the time it engages. As in I have already slipped & slid my way through the snowy stretch. Any thoughts on what if anything can be done to make it work more quickly?

 

Should be seconds. Shift into 4wd hi while moving forward in a straight line but let off the throttle a bit to make the shift easier.

 

The 4WD system in 4th gen’s can also be used full-time as long as the center isn’t locked so you can just leave it on when anticipating mixed conditions too.

 

More so with the electronic transfer case select than the manual is the need to regularly cycle the mechanism on a monthly basis…this is to keep the mechanical part of the actuator freed up.

There aren’t any external features of the electronic version one can ‘service’ and unfortunately, replacing the entire assembly is a tricky and expensive process. Fortunately in your case the mechanical part appears to be functional aside from the delay as well as the electronic side of things…to a point.

Question: when you select 4WD Hi does the shift indicator immediately start blinking or does it too take awhile before it does blink?

if the latter it may indicate that somewhere in the control module (dial assembly) there’s a fault, be it an intermittency (switch contact corrosion) or a fault somewhere in the wiring harness. Perhaps try reseating all electrical connections (with the truck off!) to see if the simple act of un-mating and re-mating connectors helps.

I remember reading about this fellow (a very long time ago on another forum) who solved his ‘sticking’ issue by overdriving the electronic motors in the actuator housing with something like >15VDC. His thought was, and it is true to some extent, that motor torque increases with voltage and by doing so he could free up the sticking actuator parts. It worked but he risked frying the electric motor’s brushes.

Here’s a slightly more in depth function guide, if your so inclined to go at it with a voltmeter and try to do some further investigation, checking the position (states) switches, etc.

 

Thanks for the file. I will look into it.

 

The more you use it or activate it, the faster and more consistent it will work...our 4th gens are a "use it or lose it" deal so be sure to activate it, or try to, once a month!

 

Exactly what I was thinking. In fact, just engage/disengage whenever you can do it safely. Odds are the response time will improve.

With that said, sometimes it just takes a minute.

 

Thanks guys. I will give it more work & see if that helps. Do I need to wait for it to engage then back to 4HI or just make it start trying?

 

In theory, you're good to engage 4WD while moving so as long as you're below 45mph. For me, I let off of the accelerator pedal, engage, and give it a couple seconds to either hear it or feel it engage. I've had some good luck by slightly turning the steering wheel (not full locks) just like you're avoiding a bump in the road, and it seems to fall into place as desired. The more you do this, the faster and more "lubricated" the system will be and should activate in a faster times...also, depending on your transfer case fluid, that can help as well if it's more fresh than not. My 4runner is a v8, and thusly Full-Time 4WD or AWD so my reference to you is based on my tundra which shares the same processes to engage 4WD...I had a unexpectedly long wait when engaging 4WD and noticed the slight turning of the steering wheel and the letting off of the pedal to make it engage faster and consistently than not doing so. Over time of using this process, it engages quicker than when I first tried. Use it once a month if you can and you'll likely never be left stranded in not having it available...or at least once a LOF change.

 

I’ve been shifting into and out of 4wd two to three times a day for the past 2 months, depending if I go home for lunch. I find if it doesn’t engage on a two count, I pop it out of drive and into neutral. It usually will engage. If it doesn’t by another two count I pop it back into drive and it engages.
The same will happen with my wife’s Tundra.

 

It took me about 3 years of using 4WD when needed before I noticed this year that it engages almost immediately with little wait or change in my steering wheel. I attribute it to it's constant use both during summer months and winter...I have no idea what actually causes it to not work immediately or what makes it work immediately, but I do know, if you don't "exercise" it routinely, the chance of it not working increases. This is both for my Tundra and my 4runner's engagement of 4L...keep your U-joints greased well and use moly-based grease (typically the least expensive) and stay up on your maintenance and you should be good to go! Folks have also taken apart their 4WD actuators and cleaned up electrical connections and ladden them in dielectric grease to better water proof them as some have noticed rust inside and that being the cause of inoperability...I prefer NOT to have to do that but if it came down to it, I suppose it's worth a try...cheapest things, first, right?!

 

OK sounds like I just need to "exercise" it more! I don't drive it every day but have used 4HI on a pretty much monthly basis & other than being slow to engage no issues. I will make a point of switching it on & off a few times every time I drive. I will try to remember to report back in a month or so with an update. Thanks again.