Eaton Elocker... electric locker for the 8.8"

[havack]

As to turning them on or off, you turn off the air to them and let them bleed down, or you turn off the power to them.

Havack!

http://home.midsouth.rr.com/broncodata

[Steve83]

An automotive differential is a mechanism for dividing the engine's power between 2 shafts, most often between the 2 axleshafts within an axle. It involves a "carrier" which contains 4 bevel gears; 2 facing each other on a shaft perpendicular to the carrier's axis (spider gears), and 1 on each axleshaft concentric with the carrier's rotation. When the vehicle is rolling straight, the spider gears don't rotate on the cross-shaft, but merely convey power from the carrier (which is driven by the ring & pinion gears) to the axle gears which ultimately turn the tires. During a turn, the spider gears spin (opposite each other) to allow one axle to turn faster than the other. The problem is that the spider gears can spin fast enough to allow ALL the power to go to ONE axleshaft, leaving the other NOT TURNING AT ALL. This is an "open" differential and is used on almost all production vehicles; front, rear, or all-wheel drive. Some 4WD vehicles are manufactured with open diffs.

The easiest solution to the wheel spin allowed by an open diff is to eliminate all differentiation by either replacing the carrier & its contents with a solid piece of metal called a "spool", or by making the carrier & its contents solid by welding everything together (a "Lincoln Locker" named for the brand of welding machine), or by replacing only the contents of the carrier with a "mini-spool". But this produces unpredictable behavior on-road.

A better solution is to limit how fast the spider gears can turn by braking the axle gears - "limited slip". This involves simple springs pushing on friction materials inside the carrier, but sometimes requires additives to the oil. They also wear constantly, so they require service to continue to function. Also, they can be easily overwhelmed by wear, engine power, or driveline torque (big tires or a heavy vehicle). Some brands of LSD's are Ford's Trac-Loc (made by Eaton), GM's Positraction, Dana's Hydra-Lok, and Auburn, and each uses a specific carrier different from the open diff's.

An even better solution is "torque biasing" in which a mechanism varies the braking effect to send the torque to the tire with traction. This type uses even more unusual carriers. GM's Gov-Lock uses an extremely complex & delicate arrangement of clock springs, counterweights, and clutches to do an effective job, but they’re famous for exploding when overrevved. The Tractech (now owned by Eaton) True-Trac uses a much simpler, more robust, & more elegant arrangement of helical gears, but still suffers from wear. Zexel's TorSen claims not to suffer from wear and is made in 3 configurations, but is only available for a few axles & transaxles.

A solution that virtually eliminates wear is the Tractech (now owned by Eaton) Detroit Locker, which uses toothed rings held in engagement by heavy springs to transmit power from the ring gear to the axleshafts. They replace the stock carrier, but require no modification to the axle housing. There is no differentiation (in the pure sense) since they act as a spool, but the differential effect is still achieved when the rings disengage under extreme driveline torque, momentarily allowing one axle to freewheel to relieve the torque. There are many copies of this design marketed under many names, and there are also "mini" versions which replace only the contents of the carrier but are considered far weaker. While VERY effective & dependable (except minis), these show the same unpredictability as a spool when driven on ice. Some also produce an audible popping during normal on-road operation which bothers some drivers.

The last & most functional type is the "selectable locker" which gives the driver direct & immediate control to change from an open diff to a spool, and a recently-introduced type switches from LSD to spool. A few older 4WD's came with this feature, and it has recently returned in a few high-end SUVs/SUTs. ARB sells the most popular which uses an air diaphragm in a proprietary carrier to apply force to the clutches that lock the diff. While effective & convenient, it is expensive to buy, expensive to install, and requires an on-board air source which is also expensive. It requires some drilling of the axle housing for the air line to be routed thru, and some owners have found air leaks to be a problem. The Eaton Elocker promises simplicity over the ARB since it uses an electromagnetic solenoid mechanism to lock the diff, but they have little history to judge their quality. Those offered in high-end SUVs/SUTs see little real use.

This is an excellent illustrated & animated tutorial on the functioning of differentials, and the rest of the web site is a WEALTH of information & links.
This is another article comparing types of diffs.

Thanks juice and havak,

Ok I basically understand those things now for the next question on the laundry list.

what comes standard on a 86 Bronco? Limited slip or open?

Now when you buy a set of lockers for 600 dollars or so that's a locker for each differential right? And also why not just run lockers front and back? And would it be a prolem if you left the back locked in all the time and just locked the front lockers when you were looking to get into so deeper stuff then usual? Or would that be bad?

Anyway just asking to plan for the future seems like a lockers are almost a necessity. Also how hard are they to lock and unlock? And how much of a pain is installation?

Thanks for all the help guys you should hold siminars;
Steve

[Steve83]

If your diffs still have the tags on them, read the second character of the second line. If it's an "L", you have limited slip - if it's a space, you have an open diff. The first three numbers are your ratio; for instance "3L55" is a 3.55 ratio limited slip and "4 11" is an open 4.11.


stevebyars@onebox.com

I was looking around and trying to see what different types of lockers are around.

Is there really a difference between the brands of lockers? Also you said you unlock them by bleeding them down or basically turning the power off or unlocking the electromagnets, how would you unlock them or bleed them would you have a switch mounted in the cab or would you have to do it on the differential itself?

Also if you can unlock what would be the disadvantage of putting lockers on both. And what would be the downside to driving around with the rear diff. locked all the time?

I read all the post a couple times and went to that web sight in one of the links. And it was helpful I read all of the diff related stuff they offered and it helped. It seems like the locker is the only way to go really to make a good combination of offroader and street driving bronco.

Thanks,
Steve

[havack]

Now this is open for debate, but IMHO a spool is a good thing for the front, IF AND ONLY IF you have MANUAL locking hubs AND DO NOT plan on using the 4X4 with BOTH wheels locked in anything but mud. The three wheel drive would be fine on pavement( a spool with only one wheel locked up front).

In short a spool on the road will kill the axles period.

Havack!

http://home.midsouth.rr.com/broncodata

[muddybronco]

ok this is off topic but i just have one pic from Xmas Eve stuck so I'm just gonna post it here. it's not of the stuck but of the aftermath, and it's the only pic i have of the bronco on 35's so here ya go. it's kinda big (160K). not the driver rear tire, it was the one that flexed down and disappeared in the gumbo... it was packed with mud flush with the tire surface until i used a stick to dig some of it out. that was some nasty gooey. i might have a pic of the toyota stuck in it, i'm not sure if that roll has been developed.




S H O U L D A G O T T A F O R D!

www.ArkansasMud.com

[slickerthanyou]

I didn't reconize it with the top on![img]/wwwthreads_images/icons/wink.gif[/img] Please tell me how to get a pic on here and if possible to get it in my sig.

<font color=blue>Backyard Builder-If I ain't drivin it I'm under it!<font color=blue>

[Steve83]

This is the most recent thread on the subject.
Here's another.
This one covers signature pics.
This is a really long thread that covers pics in general.
This gives the markup for a clickable pic, which is what my signature is.
Admin is requesting that <font color=green>sig pics be around 10Kb</font color=green>, and certainly <font color=red>no more than 15Kb</font color=red>.
In the future, you can use the Search function at the top of every page to find old threads like this.


stevebyars@onebox.com

Ok my locker search continues.
And I needed some advice on a product called the Ox-Locker it is a cable operated Locker there isn't much info on the site but maybe some of you have heard something about it.

Check out the link and tell me what you think of it.
Thanks again guys,
Steve