Difference b/t center diff lock and 4wd?
- Thread starter jgmx893
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BlackWorksInc
New member
Simply put, 4WD engages the front differential to be powered by the transfer case. In the 4Runner, both front and rear diffs are open and the central differential inside the transfer case is of the Torsen design. With 4WD engaged, but CDL (Central Differential LocK) disengaged, the front and rear differentials will be provided varying power based on condition and mechanical advantage; i.e. it might be a 30/70 split sometimes or a 20/80, ect ect. With the CDL engaged, the transfer case locks the center differential and forces a 50/50 split regardless of conditions. The front and rear differentials are still open so ATRAC will try and mimic a locker/LSD to limit slippage left & right, but the CDL will lock power output to the front and rear axle at 50/50 so you can crawl out of muck, tough situations, ect ect. This is all explained in your Owner's Manual if your vehicle came with one when you purchased.
zopperman
Moderator
:welcome: where are you in VA?
wyanrard
New member
^this was my question
I use my 4runner to make deliveries when winter weather is too much for our cargo vans. We get 3-4 big storms per year, on average, but in 6 years I've never encountered a situation that required the CDL. I only lock it when I want to turn doughnuts in an empty parking lot. The CDL turns off stability control, which can be just a little obtrusive when it cuts throttle at a bad time, but is overall more helpful than not for me in the city driving that I do most of the time. So I'd say it is a mistake to ruitinely engage the CDL in gnarly winter weather.
Now I'm sure that the guys who go wheeling routinely engage it.
To put it a different way, with the center diff unlocked, the front and rear driveshaft can turn at different speeds. This is important on dry roads because when you go around a corner, the rear differential tracks a shorter path than the front differential, so the two driveshafts need to turn at different speeds.
When you lock the center diff, the front and rear driveshafts turn at the same speed. Only lock it on a slippery surface (or on dry pavement if you are not making any turns).
When you lock the center diff, the front and rear driveshafts turn at the same speed. Only lock it on a slippery surface (or on dry pavement if you are not making any turns).
kevinpt
Senior Member
im in the richmond / glen allen area, if you do any big mods and need help let me know
edit: its good to see more people around here on the forum. only people i have seen driving around town are parboy and Tedstryker
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jgmx893
New member
Cool, yea if you see me driving around my 4runner is dark grey/black with a few stickers on the back (one that says AMA). I put up a few pics in the pic thread of it. Won't be doing any mods anytime soon (maybe like 10 years haha). Waiting to eventually buy a truck to really do anything to a vehicle.
zopperman
Moderator
"Only lock it on a slippery surface"
Is it safe to make turns at the beach (deep sand) on 4Hi or 4Lo with center diff locked? Does driving in deep sand qualify as slippery surface?
Please advise
JB.
New member
Yes, safe and recommended.
Don't worry about center diff lock. It's not designed for pavement, but it's also nothing to worry about.
More reading in the link below if you're interested.
http://www.toyota-4runner.org/4th-g...pavement-center-diff-lock-vsc-off-switch.html
Absolutely lock the center diff on the beach. Sand allows the tires to easily slip, so you will not bind the drivetrain. The problem only occurs on pavement where the friction between tire and road prevent the tires from easily slipping.
WXman
New member
I'm a fan of shifters and mechanical linkages because they don't fail nearly as often... but I will admit that the way the 4Runner is set up is pretty cool because you can choose 4-Low and leave the center diff. unlocked. Then you get the ability to crawl without the steering resistance that comes with other low range systems.
Ukraine Train
New member
When the dash light is illuminated, does that mean the center diff is locked or unlocked? For some reason this isn't clear to me.
