When do lockers outperform tire chains? - Steel Soldiers::Military Vehicles Supersite

cranetruck · 05-23-2008, 06:41

To continue the discussion on differential lockers, under what conditions are lockers better than tire chains? Assuming that the time to install the chains is not part of the formula.
I have driven my deuce in snow and mud with chains and would think that they will outperform lockers in many situations....

Note: I don't think the GI tire chains are the best, in particular for driving on hard (=paved) surfaces.

CUCVFAN · 05-23-2008, 07:48

I'm not sure this is really an apples to apples question. A tire chain improves the "bite" of a single tire/wheel. Lockers do nothing to provide additional "bite" for the tires. They have similar effects, but it's not really a great comparison. With that said, the terrain and tire design have more to do with it than anything, IMHO.

In mud, lockers work well, but only when you have a tire that is designed for it. If you're mudding with NDT's, I'd take chains, or better yet, BOTH! In sand, I would say lockers would be better, but I have no data to back this up, but the traction of a single tire would not be as important as forcing all driving tires to apply the same torque. Dry, rocky terrain, I'll take lockers. In snow, chains win hands down. My

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crusty · 05-23-2008, 07:56

When one wheel is not in contact with the ground, a locker is the only way to go.

cranetruck · 05-23-2008, 08:02

Quote:

Originally Posted by crusty

When one wheel is not in contact with the ground, a locker is the only way to go.

...or applying brakes lightly if not selectively, to the free spinning side.

CUCVFAN · 05-23-2008, 08:05

Very good point about one wheel on the ground. Of course, with 2 rear axles and 20,000lbs on top, you're not usually in a position to have a rear wheel from each rear axle off the ground. It can happen for sure, but no many do much rock crawling with their 5-ton... it would be cool to watch, though.

BKubu · 05-23-2008, 08:32

CUCVFAN: That is the type of thing I'd prefer to see someone else do with THEIR own truck while my truck looks on from the comfort of a garage!

cranetruck · 05-23-2008, 08:35

Quote:

Originally Posted by CUCVFAN

Very good point about one wheel on the ground. Of course, with 2 rear axles and 20,000lbs on top, you're not usually in a position to have a rear wheel from each rear axle off the ground... .

Well, if you drive on a side slope this is often the limiting factor, the upper side will lose traction and you are imobilized....

M543A2 · 05-23-2008, 08:45

No one has mentioned snow and ice. In my experience, chains are the best for these conditions when off- road predominantly. I try not to run long distances on-road with them.
Regards Marti

cranetruck · 05-23-2008, 08:51

Quote:

Originally Posted by M543A2

.....I try not to run long distances on-road with them.
Regards Marti

This is where the design of the chains come in, some are good on hard pavement others (GI issue for the deuce, anyway) are lousy, shake the truck to pieces.
The type of chain pictured below should be pretty good on pavement, but probably cost a small fortune.

Elwenil · 05-23-2008, 09:05

Before I type this, I will say that my experience with lockers and tire chains is with 4WD civilian trucks rock crawling or in mud and not MVs, but I think the basics are pretty much the same, but the application can sometimes be very different. With that said, I think they are both useful traction aids but chains are not always practical. Chains can be very dangerous on rocks since you can sometimes get most of the weight of the vehicle on one wheel and therefore hanging on one crosslink. There are no chains made, to my knowledge, that are capable of supporting the entire weight of a vehicle and breakage is inevitable. It becomes a safety issue when you add wheelspin into the deal as sometimes that is all you can do to either keep momentum or floatation. I realize that this probabaly doesn't apply to most MVs due to the weight and low gearing.

Lockers are a bit more versatile, especially selectable lockers. They allow true 4WD as a vehicle with front and rear lockers has all 4 wheels pulling equally. An open differential will send all of the available power to the wheel that breaks traction. This can make it hard to regain traction and can kill any momentum. Applying the brakes lightly is known as the "poor man's locker" and can work, but it is also the quickest way I know of to send the center pin completely out of the differential. I have done that myself, twice. Both times with a C-clip axle, not fun.

In short, they are both useful, but they are very different. Chains are frowned upon because of the noise, the risk of body damage, road damage, risk of flying debris if they break, and the manual labor involved to put them on. They do dramatically increase traction in light mud, snow and ice but they are not easy to put on and take off and since the can be dangerous in some situations, they are pretty much forgotten to many wheelers except for snow and ice duty. Lockers really have few drawbacks. They can change the driving characteristics on pavement but they are easily compensated for. They can cause added tire wear, but that is considered a small thing compared to what you gain. Some say that break parts, but I disagree with that. Generally it's trying to do something your vehicle can't do that breaks parts, the locker simply allowed you to get to that point, which you couldn't have reached without the aid of a locker. Again, they are both useful but the locker is much more useful in more situations where chains can have several drawbacks. Just my .02