4x4 Dummy

[mjohnso1]

Hey Guys,
I have a question regarding the e-lock differential and its use. Can somebody explain to me when I would need to use the e-lock? I guess conceptually, I don't see the difference between it and 4LO. Probably a dumb question, but...........

[tagjet]

It locks the rear wheels and gives equal power to both wheels unlike a posi rear which shifts it to the wheel with the greatest traction. I just wish Nissan made it usable in 4HI also.

[pagerdaddy]

Originally Posted by mjohnso1

Hey Guys,
I have a question regarding the e-lock differential and its use. Can somebody explain to me when I would need to use the e-lock? I guess conceptually, I don't see the difference between it and 4LO. Probably a dumb question, but...........

MJ,
My Titan is a 4X4, but doesn't have a locker. As far as I know, the 4LO
just lowers the ratios, and is used for crawling through rough stuff at a
slow pace.

My Dad had a 4X4 tractor that had a locking differential on the rear. All
I had to do was step down on a lever, and both rear wheels were forced
to pull. I didn't have to use it very often, but the times I did it really made
a difference, especially one time in some deep mud.

My new Yamaha Rhino ATV has a posi-trac setup on the back, which I
take it means both back wheels pull most of the time, and an e-locker
on the front. It really makes the steering more difficult, and I only use
it in the worst places.

I'm sure someone else can give you a more accurate and detailed expla-
nation of what the locker will do. I haven't found a real need for one yet
on a truck, but I'm sure there are many here who have.

[Ape0r]

In an axle that uses an open differential, if one wheel cannot get traction, all of the torque that is delivered to the axle will go into spinning that wheel, and the other wheel will sit totally still. To overcome this, limited slip and locking differentials have come into use. In a locking differential, the two wheels are literally LOCKED together, and are forced to turn together, thus each wheel gets half of the torque that is delivered to the axle. This way, if one wheel loses traction, rather than that wheel spinning out and the truck sitting still, the other wheel can still power the truck forward.

4LO is totally different. Four wheel drive simply engages the front axle and splits the engines torque between the front and rear axles. However, unless there are locking differentials, the scenario explained above can still take place, where one wheel on each axle spins uselessly. 4HI simply engages the front axle, while 4LO adds an extra gear reduction between the transmission and the axle to as let the truck crawl forward.

Having the front axle engaged(this is all that putting the truck in four wheel does) does not have any effect on how the rear differential behaves in low traction situations. This is where the locker comes in, when you engage it, not only is the front axle locked to the rear, but the two rear wheels are locked together. (I don't know if Nissan sticks the e-locker in both axles or just the rear, but I have a mechanical locker in the rear end of my Chevy.)

Check out these two articles from how stuff works for more information:

How differentials work:
http://auto.howstuffworks.com/differential.htm

How four wheel drive works:
http://auto.howstuffworks.com/four-wheel-drive.htm

[TrojanDan]

After it rained pretty hard in socal Saturday night, I went wheelin with some buddies yesterday. There was a massive mud bog, which was eatin trucks alive! You could really tell when a truck didn't have a limited slip or locker. As soon as somewould would begin to get stuck, they'd hit the gas. Even though 4wd was engaged, only 1 rear tire and 1 front tire would spin. It was some real life proof that having 4wd and big tires doesn't make your truck invincible, and how helpful an LSD or locker would be. That is the major difference between having 4lo and a locker, even in 4lo only 1 rear tire will spin when you're stuck in the mud and hittin the gas.

[mjohnso1]

Thanks guys.

ApeOr......good explanation, that does clear it up for me. Now I just have to see if the front axle engages also when I puch the switch. The Nissan book wasn't clear. Thanks.

[Sammy Sandbag]

Originally Posted by mjohnso1

Thanks guys.

ApeOr......good explanation, that does clear it up for me. Now I just have to see if the front axle engages also when I puch the switch. The Nissan book wasn't clear. Thanks.

IIRC, the Titan is wired to only allow you to lock the rear when the trans-x is in 4LO.

[igotatitan]

Originally Posted by mjohnso1

Now I just have to see if the front axle engages also when I puch the switch.

Your front differential is not locking. Only the rear.

Because you're a 4x4 newbie, I'll give you this bit of advice: Never under any circumstances should you activate the locker when both rear tires have traction and there is a chance that you make a turn. You will destroy your differential - very quickly.

[mjohnso1]

Thanks 'igotatitan!!!'