4L and CDL exercising

[Dan Lee]

4WD is new to me. I understand that I should exercise the LX CDL and 4L modes regularly (once a month?) in order to keep them in functional condition and prevent seizing / what not.

But what is the recommended exercise and for what duration? Is it enough to go to a dirt lot, put it into 4L and lock the center diff, and then drive a circle? Should I exercise 4L alone first before locking the center?

What do you guys recommend for 4L / CDL maintenance use -- trips for which I'd actually use 4L / CDL are probably going to be just a 2-3 times a year.

1) Mode?
2) Duration?
3) Driving course?

 

[NLScooby]

I'll usually put it in 4lo on a dirt road (we have a place we go mountain biking) and then I'll lock the center diff as well. Ill make some Left and right turns just for fun... once a month would be great but I am guilty of not doing it that regularly sometimes.....

 

[Narkhelek]

FYI: you don't need to be on a dirt road to shift in to 4L with the 200 full time 4wheel drive system. It won't cause any damage due to binding like you would have with a part time 4WD system. Coming from part time 4WD trucks, it kind of blew my mind when I realized that. As for the CDL, you'll want to be on dirt. You don't need to drive very far to exercise either. It's more about the the switching between modes than about actually driving in either.

 

[linuxgod]

FYI: you don't need to be on a dirt road to shift in to 4L with the 200 full time 4wheel drive system. It won't cause any damage due to binding like you would have with a part time 4WD system. Coming from part time 4WD trucks, it kind of blew my mind when I realized that. As for the CDL, you'll want to be on dirt. You don't need to drive very far to exercise either. It's more about the the switching between modes than about actually driving in either.

I would be leery of putting it in 4Lo on paved roads. I know the little visor card doesn't specifically say it, but coming from a part time system on my 3rd gen 4Runner I'm skeptical. I did it once when I was trying to figure out how to clear the flashing CDL - light finally went off and I flipped into 4Lo when stopped, turned CD on, moved about 10', then tried to disengage, and I had a helluva time getting the system to unlock from 4Lo. When it finally did it made a loud clunk like it had been binding up.

More importantly, I've had the dreaded flashing CDL from time to time, and engaging 4Lo by itself doesn't seem to clear up the issue. Locking the CDL for a bit does. So if you want to exercise the system you'll need to engage the CDL, which means dirt or gravel roads, at which point it's definitely safe to use 4Lo.

I try to drive my truck down the gravel alley behind my house once a month, maybe 200 yards, in 4Lo with the CD engaged. Seems to reduce the flashing CDL frequency but not eliminate it, so to answer your question no you probably need to do more than drive in a circle. IIRC with my 3rd Gen 4Runner Toyota recommended driving 10 miles per month with 4WD engaged. Living in the city it's not really possible for me to do that.

Just my $0.02.

 

[Dan Lee]

Thanks guys. I'll try to exercise the CDL and 4L regularly. Probably can't do 10 miles per month (let's say 5mph, that's two hours). Hopefully, just repeatedly engaging/disengaging and a little bit of driving will be enough.

 

[TeCKis300]

4Lo is fine anytime, even on asphalt, without any concerns of binding and stuff. It's just ultra low gearing. I use it often when backing my trailer for the fine control.

It's the center diff lock that shouldn't be engaged if you are going to be doing any sharp turns in high traction situations.

I try to at least actuate these functions regularly. Not for much distance at all, but at least switch between them ever couple months or so.

 

[Dan Lee]

Thanks. Okay, I'll plan to exercise 4L more around the house when there is no traffic. I can keep it slow and straight. I'll do CDL as well as long as I can keep is straight but exercise it more thoroughly when I'm on sand.

 

[Malleus]

I had a "sticking" problem with mine last winter. I didn't have time to look into the problem, and I had "free" service scheduled, so I had the Lexus dealership look at the systems for me. The diagnosis was no discernible fault, which led me (and the tech) to believe it was lack of use. I didn't get off-road at all last year; I have a fleet of 80s and it's hard to divide my love.

From personal experience, and I've had my LX570 for going on six years, all you need to do is engage the systems. That means cycling the actuators only. Driving, forward or backward, is exercising the gears, not the actuators, which is what sticks.

I don't know this for a fact, but my strong belief is that the seals on these connectors and actuators aren't as good as the 80s are. If they were, you'd never have them "stick". I need to open my connectors, clean and grease them before this winter, so I'll know better then what those look like, but I think I'll find they have trash in them, and so do the solenoids.

FWIW, I engage both systems before I leave the house for work. It takes an extra 30 seconds, and since I've been regularly engaging both systems, they work much more like they are supposed to. I do have a "clunk" when the VC is engaged/disengaged, but I think it's a driveshaft related noise; these drivelines have had that "feature" since they were introduced.

 

[Dan Lee]

I can do that. Although in my experience, engaging the CDL requires some forward movement while engaging. But slow, straight and just enough for the CDL to engage should be enough, right?

 

[cru1s3r]

At a minimum, I engage 4Lo once a month out at our barn (dirt, gravel, small bumps) on both of our vehicles for about 1/2 mile. It's good to know that all systems work in advance of really needing them. Is this required on the LC? Can't say. However, on our Silverado, I've heard the legend that, if you don't use it, the system will have a greater chance of not working when you need it.

 

[Malleus]

I can do that. Although in my experience, engaging the CDL requires some forward movement while engaging. But slow, straight and just enough for the CDL to engage should be enough, right?

The VC and Hi/Lo shift solenoids do not require any vehicle motion, as a matter of fact, you can't (at least I can't) shift Hi/Lo unless you're in neutral and stopped. The VC is supposed to shift up to 60 mph, but I have no idea why. I can't ever imagine going that fast and needing it spontaneously (more than I need my brakes anyway).

That goes for the switching functions only. FWIW, I always drive mine to the end of the street, yes it's a straight shot from the driveway to the stop sign, to assess the function of the drive system. Making "S" turns are only necessary if the "locks" don't "unlock", as per the owner's manual. Remember the transmission isn't connected to the steering linkage, it doesn't know if you're going straight or not (and the rear wheels never turn, do they?)

 

[Haggis]

Thanks to this thread I put mine in Lo for the first time. All went well and no issues switching back to 4 Hi. I'm amazed at that crawling first gear, better than my manual Tacoma.