Engage 4HI and 4LO once a month?

Hey all,

quick question here. Reading about 4 X 4 gears seizing if not used.
I primarily use as a commuter on regular roads.
There is a straight stretch of highway that I think I can engage my 4HI when in slow moving traffic, but should I be switching into 4Lo as well on asphalt?

Not sure if 4LO would mess anything up given I'm on the freeway rather than a dirt road.

Any insight to this would be much appreciated

 

You’re mostly exercising the actuator. You cannot drive at freeway speeds in low range because of the gear reduction.

 

Straight lines is fine but while monthly is the recommendation every so often at least will likely do. Heck, you could at least do both monthly in a parking lot.

 

I would pick a nice straight quiet road to engage 4hi. Too much other stuff to be paying attention to on the freeway, and you may find yourself having to shift back into 2wd in less than ideal situations. The transfer case has a speed limit at which it can be shifted between 2wd and 4hi. It’s on your visor.

4lo requires you stop and shift to neutral to engage or disengage. So you can only really do that on a straight side street off to the side.

 

No, don't engage 4Lo on highway. I wouldn't do it on pavement but if I did - only if nobody's around, like empty parking lot and on only driving straight. On the bright side you don't have to engage 4Lo every month, basically 4Hi is enough to keep transfer case lubricated according the manual. Maybe turning on 4lo once a year when you on a dirt road if good enough, but it's just my opinion : )

 

I have a calendar reminder for every 60 days to engage 4H & 4L. Yeah Yeah Yeah, roast me all you want. My truck is a pavement princess.

I pick a parking lot and engage 4L then cruise around for 7 - 10 minutes at low speeds. Then I engage 4H, hop on a highway with a long straight away and drive 6 - 10 miles. Once a month is fine, but the manual (I think) recommends a few times a year. Maybe get in the habit of doing it once every 2 - 3 months.

 

In my experience, exercising the transfer case is more critical with the electronic transfer actuator, such as the SR5 and Limited. I have a high mileage 1st gen Tacoma with a manual transfer case that was rarely used by the previous owner and it works great. I have a Sequoia that the wife hardly ever uses 4H or 4L and the electronic transfer actuator is inop.
ADD (front axle) issues have never been a problem for me on all my Toyota’s.

 

you have 4LO actuators that should be exercised.

 

Lock the rear diff as well if you have it.

 

Decades ago I had a very good service manager tell me the most 4WD problems he saw were the “Soccer Moms” who never used 4WD until it snowed and came in complaining it would not work. Cause, generally a seized actuator.

So for decades I have exercised both 4LO and 4HI monthly. LO in a parking lot after hours and HI on relatively straight roads. Never had a problem with a Jimmy and 4 T4Rs, high mileage on all but one

 

You should update your profile to include your location. It helps with answers to questions like this.

Example 1: Profile says Los Angeles. The answer is, you should go to Holcomb Valley and exercise your 4H and 4L once a month.
Example 2: Profile says Seattle. The answer is, you should go to the Olympic Pennisula and exercise your 4H and 4L once a month.
Example 3: Profile says Kansas City. The answer is, your should go to Turtle Creek ORV and exercise your 4H and 4L once a month.

See, it's really important to include your location in your profile so you can get specific answers to questions. Otherwise, I have no way of knowing how you should handle your 4H/4L. Hope that helps indeedy.

 

I think merely activating the electrical actuators on/off and maybe roll the tires a revolution or two max. In a straight line of course-idle engine speed.
My 2 cents

 

I turn my 4HI on whenever I remember to.

4LO if I remember it happens once a year.

 

It should of course, but I remembered to do it only for difficult off-road situations, sometimes it was 3 times a year, sometimes I drove 2 years without using 4lo . I had my SR5 for 11 years, and at the end everything worked, so I suppose 4lo once a year should be fine. But I engaged 4Hi every month at least for 10 miles.

 

The owner’s manual does specifically advise exercising the 4WD system:

Four-wheel drive usage frequency
You should drive in four-wheel drive for at least 10 miles (16 km) each month. This will assure that the front drive components are lubricated.
​

If I understand the mysterious inner workings of the transfer case correctly, on part-time 4WD models, when in two wheel drive mode the drive chain does not spin, and the upper half of it is high and dry. If I had to guess why Toyota advises a little exercise, I suppose this to be the reason. To keep the chain lubricated to protect the links from freezing up. I may be wrong, but Toyota must have put those instructions in the manual for a reason.

As for the actuators, there is evidence, though anecdotal, that the most frequent failure of the 4WD system is seized actuators, whether the shift actuator, the ADD, or the rear diff lock.

As for driving in a straight line on pavement, that is something that we have all just made up and decided is okay, though it contradicts the manual which says to use 4WD “only on tracks that permit the tires slide, like off road, icy, or snow covered roads.”

Take that for whatever it’s worth.

 

Example 4: Profile says Dallas/Ft. Worth. The answer is, go to the nearest mall and exercise your 4H and 4L once a month. Don't be scared of those curbs! Disconnect that sway bar if you need extra articulation.

 

Sure 4LO only when needed off road but if an actuator is stuck you might not have it when needed. That is my point. My take is regardless of experience better safe than sorry. JMHO

 

True on made up so to speak, but going straight puts no binding on the locked wheel mechanisms. The problem on pavement is when you turn the outside wheel needs to travel further than inside but can’t because it is locked to the inside. Thus things bind up as the wheels can’t slip as they would do in sand, mud, dirt, snow, etc. I have been doing this for decades in many 4WDs and never had a problem. Not to say I might but odds seem extremely low. I think the manual is written assuming you are going to likely make turns on pavement and chooses to just not mention “straight”. Just my opinion of course.

edit. BTW when you shift from 4HI to 4LO, a gear in the transfer case is moved on a sleeve to the low position ans vice versa. Another reason to not go a year on exercising it

 

I live in a 4 months a year snow chance area, so if we have a few inches of snow I engage it then.

 

The once a month for two items. First it keeps the parts lubed and in working order. Second and most importantly is the “computer” that these use needs to also be used frequently enough to ensure it doesn’t seize. The computer for these are basically switches and you need to activate all systems at least once a month just so it remembers how to. Otherwise if the memory gets lost or the old chips seize you 4x4 is worthless. These are not modern computers by any means.

 

Crawl control if available
Mainly for lubrication n all that
But so your used to the sound…lotta people think they’re breaking the truck when it’s just doing its thing

 

One thing not mentioned is gear oil is hygroscopic. In addition to exercising actuators and keeping everything lubricated, driving in 4H long enough to heat up the front differential and push out any moisture that has had a chance to accumulate is a good idea.

 

Since it's the cold and wet season in my area of the NW, I just drive around to my backyard and engage 4H,4L, the rear locker once a week and drive in a large figure 8. Tire traction is not in a bind because the surface is wet and muddy (wild land grasses).
I activate the locker, hear it engage, and continue with my figure 8's. I do this a couple times to exercise my finger on the overhead switch.
But when there's enough snow on the ground, let the fun begin. I lock the hubs and diff lockers in my TJ and do slow speed drifting.
I bet the neighbors horses wish that they could do 4-wheel drifts. But they run the fence line beside me.

 

No location noted on the original post, so no info there. Anyone with access to a dirt lot of any size can do the same. I happen to have areas like that scattered around Albuquerque. Those allow putting the transfer case into 4H, 4L, engaging the rear locker, turning on MTS, Crawl Control, etc. to my heart's content. One is 5 minutes from my house. I prefer doing this to engaging 4H on a straightaway, although there's nothing wrong with that.

 

Yesterday is the first time since winter (8 months ago) I did that after reading the post. The 4-wheel drive light kept blinking in the first try. Shifted it to 2-wheel then back to 4-wheel and it ran normal.
I probably did that 2 times every summer for the last 6 years but this year I forgot.
I have a TRD Off Road.
No I seldom do off road and only crawl the curb at the mall once in a while.