1999 Siverado Locking Deferential

mstolz

I have a 1999 Silverado that came with a locking
rear deferential. I know what locking and limited
slip are, and my truck acts as though it really has
only limited slip and not a locker as advertised
in the options list. This is one option that I did
not research real well. With out getting the axle
tag off the truck, does anyone know what this axle
should really be or what Chevy advertises it as?
Does Chevy just say this axle has locker
capability, when in actuality it is just limited
slip? I would expect a button on the inside that
would turn off/on a locking deferential.

markbuck

Locker rear end in this case is automatic, once a certain amount of wheel slip occurs, your diff will mechanically engage the nonslipping wheel.

My best seat of the pants explanation is that the locker has a sharper (jolt?) engagement than a clutch type limited slip.

quadrunner500

http://www.torquecontrol.eaton.com/

zbad71

The Eaton locker makes one revolution of the wheel that is not getting traction and then it locks.

sandman9

It is a true locking deferential, as zbad71 stated , kicks in with on revolution of the wheel after slipage, stays on till about 15 mph

markbuck

Seat of the pants agrees with Zbad71's answer of one wheel rev, then lock.

While playing rally truck this weekend, was able to get locker engagement at speeds up to and exceeding 50mph. Doubt there is anything in the locker to disengage it at speeds over 15mph.

artp

When one buys a limited slip rear end and has 4wd does that mean the front axle is limited slip too?

markbuck

Nope. I figure I have a 3wd.

zbad71

From stock, a 4wd with locking diff is actually just 3wd. There are aftermarkets that you can put on that make front diffs locking also. However, I don't feel that they provide that much more traction, they are noisy, they are costly to install and run (both in the initial cost and maintenance). You have to be extremely careful with them too. It can strip out your front diff or transfer case. Even AWD vehicles don't have a "true" AWD or "true" 4WD. AWD vehicles are have a traction sensing system and to my knowledge there isn't one on the market that ever allows all 4 wheels traction at the same time.

Does anyone know of one that does? Even the Jeeps that claimed "full time" true 4WD only had 3 wheels with traction at one time. How would you turn the vehicle in 4WD if they did?

mfreeman1

I believe the front locks, that is why you shouldn't drive it on dry pavement in 4wd. With 4wd engaged, it is hard to turn sharp because one of the wheels has to break loose a little to allow one wheel to role more then the other.

This is my understanding,
Mike Freeman

zbad71

You are correct. I thought that is what I said, but maybe I didn't say it very well. In 4WD, you actually only have 3WD and only if you have a locking or limited slip rear axle. Without the locking or limitied slip rear axle, only the right rear and front left are "driving" the mementum of the truck.

The front does not "lock", it engages the front drive axle and the hubs. This is different than having a "locking front diff" where "both" front wheels "drive" the momentum of the truck.

Did I explain that very well?

markbuck

That difficulty in steering (driveline windup) is actually a load due to the fact that the front driveshaft needs to turn slower that the rear when going around a turn. If either front tire slips, then the load on the front driveshaft is eliminated. Full time 4wd or AWD solves this problem by putting a differential in the transfer case.

artp

If standard 4x4 doesn't have a differential, how could it NOT be locked?

Correction... the rear drive shaft needs to turn slower in a turn.

markbuck

Standard 4x4 has two diffs, one for the front axle, and one for the rear. Full time and AWD have a third diff, between the front and rear driveshaft.

artp

someone mentioned that only SOME 4x4's have a front differential. I already know the point you'll make next.

My question is - if there isn't a front differential, how could the two front wheels NOT be locked?

It does seem logical to me that every 4x4 has a front differential, although the terminology may change.

artp

I see your point markbuck, you were speaking of a THIRD differential in the transfer case. Sorry, didn't read your original post correctly.

mstolz

Does anyone know what the Axle Tag or data plate should read for this option. The reason I'm asking is because my axle does not seem to behave like the description at the Eaton web site. While 4x4ing with a friend, he said he observed opposing front and rear wheels spinning. He said the rear wheel that was not spinning appeared to look like limited slip. The one that was not spinning, looked like it was engaging and disengaging quickly. Never totally locking. I just want to make sure I got what I paid for!!!!!

meredith

As a result of 30 or more days of inactivity....

this topic is being "frozen." It will be archived or deleted in the next 10 days or so.

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