Limited Slip / Locking Differential Redux

Given your demands, I suggest you strongly consider an automatic locker. I have automatic lockers in my Jeep, and I would not consider another Jeep that was not equipped that way. Having siad that, if trhe road is off camber (slanted to the side), the rear end tends to drift to the low side of the roadway. This is never a problem offroading, but it could be a significant problem in the snow. If you MUST drive in snowy conditions, then this is the ONLY reason to not consider an auto locker.

An auto locker is one that UNLOCKS automatically as stress builds on one tire or the other. If you lock your manual locker, it behaves like a spool and locks the two axle halves until it is switched off. The problem here is that unless the tires can slip on the ground to relieve the stress, you could find yourself with a broke axle or diferential at a very inopertune moment. The automatic locker is one that is installed, and you never have to do anything. The downside is that it might unload the stress while driving on the street, and it does this with a bang and a lerch to the side. When my Jeep unloaded in this manner after I bought it, I had to call the seller and express my concern. He assured me that it was normal, and when driving off road, the locker works perfectly.

I have the Detroit Locker in my Jeep CJ5, both front and rear axles. My rear locker is known as a full locker, my front one is sold as the EZLocker. The front locker is a lighter duty, and perhaps perfectly suited to your truck and your stated demands.

Thank you for your reply: your advice regarding snow sounds reasonable (as far as my limited knowledge goes). Gods save me if I ever feel the urge to drive in snow! Argh! I buy groceries for about 40 days at a time just so that I do not have to drive into town often: this winter we had a great deal of snow, and the owners of the ranch were kind enough to drive me into town and back (their F250 did a good job, though to be totally frank I nearly wet my shorts from terror in a few spots in the road: there are sheer drops of 300 to 400 feet in places, being driven past while on ice and snow).

Considering your kind recomendation, I see that the "Powertrax No-Slip Traction Systems" is likely to fit in my 2WD "open" differential case and I can probably do the job in two hours or less if all goes well--- but I would have to measure the case (7.5 or 8 inches--- I do not know). I've read one on-line review, and I will look for more.

I must admit that in the 14 years I have owned the pickup I have never changed the differential oil. Maybe I had better buy a few new parts, if I do an install, such as the trust washers (which I saw a diagram of--- I ain't no fancy auto mechanic). I have never replaced the break drums, and I have never replaced the break shoes! Long past time that I did that: the pickup stops only via the front disc pads.

Yeah... the more I think on it, the more I like your idea better: forget the limited slip idea and get an auto-locker.

You mentioned an "off camber" road: we got that, in spades, here! :-) All told, I travel 23 miles on dirt to get into town, 12 of those miles on "primative" road and 11 miles on "improved."

My brother has the NoSlip in his CJ7 (with 4 cyl motor), and he likes it. It behaves well on the street -- no banging and lurching to the side as it unloads -- and gives him excellent traction off road. I had forgotten about that product, but now that you mention it, I think it is an excellent choice, if they have it for your differential.

I don't know what it take to get your diff apart, but my brother installed his NoSlip at home, and I helped a buddy install an EZLocker at his house. If you have the skills and tools, there is little reason that you couldn't do this job. Dirt is an obvious issue ...

Thirty years or so ago I lived on the Jicarilla Apache reservation in Northern NM for a couple of years. There is a lot of oil bearing shale dirt in that area that turns into axle grease after a rain. Any crown, or slope in the road would put you off of the road real quick with a locker, and even quicker with a double locker. There is/was drops like you describe along the Navajo river.

El Paso Natural Gas used skinny high profile mud tires trying to penetrate through the surface goop in order to get traction. If they used chains they put them on the front tires of a 4X4 instead of the rear. I took their advice on my IH 4X4 and it helped to keep you going where you pointed the front end as long as you were under power.

A lot of the Jicarilla's had two wheel drive 3/4 ton PU's and had two extra mud tires, with chains installed on them, that they kept in the back. But, these were no ordinary chains. Over each cross link they installed logging chain links that were loose. When those boogers were turning they took out big divots and threw mud 20 to 30 feet in the air. Yes, you might say they were self cleaning chains. Tribal members went places I wouldn't even try to go in my 4X4 with these chains. You might try this on your 2wd before you invest a lot of money in a locker.

Think twice before adding any kind of locker or LS if you have off-camber road, as either can cause you to slide sideways very quickly. A push-button locker should always be viewed as a tool for getting un-stuck, and never a tool for driving with. So I would prolly look at an Air-locker type setup that you can engage when appropriate, and avoid any LS or auto-locker systems.

I'm familiar with the NM greasy clay, and usually it's not very deep. A tall, skinny tire with an extremely aggressive tread is your best weapon, and maybe some weight in the bed.

I forgot to mention that your parking brake makes a very effective "limited slip" tool. Just apply some pressure and your wheels will slip a lot less. Needless to say, you don't want to do that for very long.

It appears that there is no version of Powertrax No-slip available for my pickup: that is one good reason why I cannot do the job. :-( They do sell a "Lock-Right" for my pickup, but I don't know if I want one of those. I am waiting for the customer service / sales person to send email back to me telling me if they have a No-Slip that will work in my pickup.

You mentioned the lack of banging and lurching with the No-Slip: that is what appeals to me over the other lockers I've seen via the 'net.

(Shudder!) Ain't nothing changed in that 30 years, I must tell you. :-)

In the three years I have been here (In Jicarilla Apache country) I have driven my automobile for as many as 30 days (well, call it 35 for good measure). In those 35 times I've driven the road, I have:

1) run off the road and plunged into a ditch four feet deep 2) got struck in mud twice

3) tried to drive on snow where the road inclines about 15 degrees, broke the snow chain on the drive wheel (rear passenger side), and plunged backwards into the abyss at 5:15 AM at -10 degrees, ending up coming to rest at the bottom of a river gorge

And I'm a careful driver! No, really. This is why we never get visitors at the ranch: it the best of times it requires all-wheel- drive with locked hubs to have any confidence getting to the ranch and back.

The above is why I am looking at a locker: I do not plan on driving on snow, ice, or mud, but this road is a nightmare even in good weather. When I drive on the road that over-looks the gorge, I drive about 5 miles per hour and hug the cliff face: if I went over the edge, nobody but the crows and coyotes would find me. It ain't being dead that I mind: it's the dying before being dead that annoys me.

That sounds like a good idea: have the front wheels pulling, like a sled or travois.

The Apaches I see here at the ranch have always been on the back of horses, collecting elk horns. :-) Fortunately I do not need to drive in mud, as a rule: I just sit in the bunk house and wait for the road to dry, even if it takes two or three months (really). I do not absolutely need to drive in mud: if there is an emergency, I can take the ranch's F250. It's just that I would like power going to both rear wheels now and then.

Looks like Powertrax does not make a version for my pickup, however.

Thank you for your time and reply.

I drive around 10 to 15 miles per hour on the dirt road, with some sections I go slower. I tried to research the problem you are warning me about but I did not see anything that suggests avoiding an automatic locker for my needs. Do you know of a web page I can look at that explains the problem? Thank you.

LockRight and EZLocker are essentially the same product sold by different makers. (In fact, there was a lawsuit sevferal years ago about patent intringment, or something along that line, because the products were so identical.) I have the Detroit EZLocker, but the Powertrax Lockright is the same thing. It should be fine for your application.

This is one of those "experience" kind of things. If you are leaning at all, or headed uphill, and wheels start to spin, the instant that the locker or kicks in you are going sideways before you can say "shit". With a lot of finesse and practice, you can learn to deal with the oddities of a locker, but those "learning experiences" can be costly.

Bottom line is that when one wheel spins, and the other is not, the stationary wheel acts like an anchor. Make them both spin and there's nothing to hold you from sliding sideways. If you learn to control the power, (and thereby the locker's engagement), you can minimize that.

LS diffs tend to do a sort of a rocking thing where one wheel spins then the other in rapid succession. Lockers just lock up, and some of them can be a little stubborn about unlocking. This is where a pushbutton locker is handy, cause YOU control if it's locked or not. You use one solely as a tool to get you out of trouble. Auto-lockers can get you into trouble.

So there's really 3 types to consider, LS, auto-locker and pushbutton locker. Of the 3, given your 2WD limitation, I'd choose the LS as it's the easiest to predict and control. You have to really spin a wheel to get it to act. Or, I'd spend the money on a righteous set of mud tires and toss 500# of ballast into the bed. Yank on the parking brake anytime a wheel spins and you're fine.

Technically, lockers so not "lock up" as if this were a random event. Lockers are always locked. The automatic lockers UNLOCK automatically -- typically with a bang and a lurch to the side -- and manual lockers have to be unlocked via the driver activating a device inside the cab. Typically -- a requirement actually -- a manual locker will remain unlocked all of the time, then locked when the driver wants the added function and capability, then the driver will unlock the locker when its usefullness has gone away. With an automatic locker, the operator has no control over the function of the device -- it is always there, doing what it does. There is no locking that occurs as a transitory state.

With a locker, both tires spin at the same speed all of the time, no matter what the traction is under a tire. The problems start when there is no traction under either tire and the roadway is tilted to the side. Depending on the friction that the roadway offers, the problems can vary from insignificant to instant disaster, or at least a serious handful of steering wheel to reel in.

Powertrax Lock-Right, according to the web site, is meant for vehicles that are driven mostly off-road: what little driving I do is mostly on pavement (23 miles on dirt, then 48 miles on pavement). If I go against the manufactuerer's recomendation and I trash my pickup's differntials, or break axles, I would feel real foolish. :-)

Just my two cents, but I'd probably get whatever is the absolute cheapest, as any of the above will most likely work just fine for your needs. Then I might spend a few bucks on some tires with aggressive treads.

Greetings Desertphile, You know, if you drove into town more often you would gain the driving experience need to keep out of the ditch. But since you're not gonna do that then I would suggest checking out the Detroit TrueTrac. Though I have not installed these yet in my Toyota 4wd they are next on the list. especially after speaking to Randy's Ring and Pinion. They are local to me and have a great reputation. Their advice to me was the TrueTrac because it is most like an open differentail in behaviour, ie you don't know it's there, it just keeps you from losing control and taking the plunge. There are lots of places selling Detroit products, I'm sure you can find one closer to you than Seattle. Cheers, Eric

Howdy and thank you for the suggesting. I was looking at a Detroit EZ Locker because I have been unable to induce the Powertrax people who answer my email. I will now look at the TrueTrac. I had no idea that there were so darn many such products to choose from. The TrueTrac is limited slip, whereas the Powerteex No-Slip is an auto-locker: I kind of lick the idea of a locker over a limited slip, though limited slip would still be better than what I have.

Gods. How is one to choose?

The last time I was in town (around 60 days ago) I bought four new tires. They now have about 80 miles on them. :-) I will look at what the Detroit EZ Locker costs, the Detrait TrueTrac costs, and the Powertrax No-Slip cost.

I really think you'd regret getting an locker. LS is the way to go. It'll give you what you need without getting you into trouble.

I have to agree - a "Detroit Locker" or "Powertrax" style "spool" differential is really meant for a full Race Vehicle, that is driven primarily or totally off-road by experienced drivers. They have very bad manners on pavement.

I watch people driving down the street in a Jacked-Up Big Tire 4X4 with 33's and a Detroit Locker, and they will scare pedestrians going around a corner - the spool locks in a "stutter" as he goes around the curve and applies power, and the tires squeal like an uncontrolled skid - which is what's happening. Smoke and smell of burning rubber. The shock loading is very hard on the axle shafts and rear end gears, all the driveline components.

If you let Aunt Clara drive the truck and she isn't carefully instructed about what's going to happen ahead of time, she's going to think she broke something - if she doesn't get scared to death that someone just hit her and drive off the side of the road...

And they can be really dangerous if you put a Detroit Locker in the front axle on a 4X4 - when they lock under power you have no choice, you are going straight ahead, period. Either back off the power to get directional control back, or go off the cliff.

You really want to install a clutch based Limited Slip like the USA factory option Toyota axles and "TrueTrac", or a worm-gear based one like the Gleason Torsen. They behave nicely when driven on city streets, and both can easily be retrofitted into the axle you have.

Or you go for an On-Demand locker. Toyota has a mechanically locking axle for trucks and Land Cruisers sold in overseas markets, it has a dashboard pull knob and a cable that actuates the lock. Kind of like shifting a transmission. Specter Offroad

imports the entire axle along with the cable kits, you can swap one in. (The castings are different, so you have to change the whole thing.)

Or the ARB Air-Locker, it retrofits into your axle. They have a special rotating seal port on one of the carrier bearings to send air pressure to a piston inside the 'pumpkin'. The differential gears go into Lock when you apply air pressure from a small electric compressor, you can walk right out of the mud like it magically dried up. And it acts like a normal open differential when the air is off.

-->--