So my neighbor just bought a new Chevy Colorado with some squirrel diesel ZR-2 and tells me HIS truck is a "real" four wheel drive and my Silverado Z-71 (I have the original window sticker that says Locking Real Differential" tells me it is not. i don't get it.. Over to you experts to enlighten me...

He's probably a little confused. Don't know about the Colorado, but I do know that some GM trucks had permanent All Wheel Drive, and others had a selectable "Auto 4WD" mode, that would engage the front axle automatically in low traction conditions. The more traditional trucks had 2WD, 4WD and 4WD Low selectable modes with a conventional transfer case that locked the front and rear axles together, fine for off road but hard on the drivetrain on solid surfaces. True AWD (All Wheel Drive) uses an open transfer that allows different front and rear driveshaft speeds, fine for all surfaces. If that's what he has, then I guess he thinks he's special

The Colorado ZR2 comes with a locking rear differential (activated electronically) as well as a selectable locking front differential. Thus, "true" four wheel drive. If you don't have locking diffs in both axles, you can't count on getting power to all 4 wheels. A few other factory 4x4s have this, mostly Jeeps with the Rubicon package, and Ram Power Wagons.

You should go buy a Unimog to one up him. Or stop worrying what a neighbor says. BTW it’s locking rear differential, not locking real differential.

^^^^This^^^^

The electric locker is the ticket in any truck front and or rear, the GM locker in the their 15-2500s will lock but only after spinning for a bit and then will unlock at about 20 mph, at times my old truck would stay locked at slow speeds chirping tires on corners.

So yes what he is saying is somewhat true if he has the electric lockers and the diesel with a good set of tires his little truck is a pretty serious off road contender.

Like K1500 said though I wouldn't let it worry me much, you can haul a larger suit case than him and get out of the way of traffic if you need to.

Real 4x4 trucks should have locking differentials, but they should also be solid axles. IFS is fine for sand racing and pavement trucks, but lockable solid axles are what constitutes a real 4x4 to me.

Thanks for being a psychic or appealing to your estrogen clairvoyance. In case you missed it (you did) it has nothing to do with one-upsmanship, but rather a technical question, but on the plus side, you have the rectal orifice schtick down pat...

This makes it easier to understand, especially the electronic locker. Mine just says "rear locking", thank you

Solid axles and three locking differentials (front, rear, center) is "real" 4wd!!

Didn’t mean to offend, the UNIMOG thing was obviously a joke. In all seriousness what I read is as follows:

1. Your neighbor says HIS truck is a ‘real’ 4 wheel drive and your Z71 with a G80 locking rear isn’t a ‘real’ 4 wheel drive.
2. You don’t get it and want to be enlightened. Is that correct?

My opinion (and the point of the UNIMOG joke), he wants to engage in a ‘my truck is better than your truck’ argument for self gratification. Any vehicle without a locker on the axle could be viewed as 1 wheel drive on that axle, but no one says it that way. You don’t see a car with an open diff and say “there goes a 1 wheel drive car”. Yes. He has a locker front and rear and you have a locker in the rear only. So I suppose he means you have a 3 wheel drive.

But what he really means is he wants to get in a d*** measuring contest with you. I don’t ever see a reason to go down that road, especially with an idiot of a neighbor. The only way you can ‘win’ a contest like that with your neighbor is to go get something that is so clearly superior to his new toy he will shut up about it. Obviously that’s foolish, which is why I would just smile and nod when he starts engaging in a ‘my truck is better than yours’ discussion.

I’m not great at math but isn’t that 6 wd?

Center diff lock is for AWD vehicles (not 4WD), which have a center diff that allows a power split between front and rear axles. This is so the vehicle can turn easily. You lock the center differential on these vehicles in low traction and they become equivalent to a regular truck in 4H.

Sorry I jumped on you then,

Thanks, but no worries. I can see how it came off as snarky. Sometimes it’s hard to convey the subtlety of meaning in a post.

Damn electrons anyway...

Nailed it!

I love the ride on my 18 Ram, but I wish it had a solid front axel.

You should have asked him what he means. He's likely the only one that would know that.

To have all four wheels fully engaged, you need lockers front and rear. Maybe he meant he had a front locker as well as a rear. Maybe he's just crazy. IDK

Doesn’t matter what who has if they can’t drive it. Real 4x4 whatever that is can only be as good as the driver

... or you could throw a football at his groin.

Everyone that buys a diesel gets on this kick that they now own a real truck.

I have a diesel crew cab with manual everything from door locks through hubs and manual shifting. Probably way more clearance than his Chevy too. I also suspect that my 78 Toyota Land Cruiser could totally wreck his aluminum rig without bending my bumper.

I did a lot of wheeling years ago, lucky if I had a posi in the rear, but never had a front unit. Fast forward 25 years & I had a Jeep Rubi that could lock the front & the year. WOW!

True 4wd is yuge, but the right tires are still a major player. Combine the 2 & you've got it. What brand they're bolted to is mostly irrelevant.

I haven't read the thread, but the neighbor might mean that his truck has 'positive traction' and your truck, as you said, has a 'locking differential'. Two completely different things.

After observing the 1/2 ton ifs and the failed differential disconnect system on the front end of a new chevy, I'd struggle to call any of them a real 4wd unless you're some urban fkn cowboy who plucks his eyebrows and drinks IPA micro brews.

Real four wheel drives are out there:

1960s-1980s chevys, Ford's, international scouts, landcruisers

Realest 4wd I ever saw, was farmer John Hetts 1991 (Palmer Alaska) flat bed one ton dodge with a cummins and a 5 speed. Ole boy would crawl a muddy, rutted trail pulling a custom trailer full of 9 round bales of hay.

He had over 200,000 farm miles on that thing.

Wiser words couldn't have been written. Dmn straight.

A gear head friend of mine made himself a "real four wheel drive" by putting lockers on both sets of axles. There was no stopping the thing in a straight line he said, but the locker on the front came out real quickly when he tried driving that thing on ice. He described it as having a mind of it's own kind of like a pea on a platter.

John,
My first memorable impression of a diesel truck wouldve been in the early 90s. Walter, an old woodsman/logger back home in northern Maine had a ford diesel one ton. Though fairly new, every inch of it was dented, he had tire chains, cables, axes and chainsaws hangin off every corner of the dmn thing. It was crude, and dirty, like him.

He was leading a few guys to a fresh cut, where we could get limbs for firewood. My father and I was in his truck. Somebody blocked the logging road with stack of hardwood logs that were larger than 4 ft in diameter.

One fella in the group hooked a chain to a single log to his f-150. He cinched up the chain and spun. He's slammed the chain and spun. Axle wrap just ah hopping that truck like it was a neutered bunny.

Walter came over with a long chain, wrapped around every one of those dmn 4 ft logs. He pulled them all at about 15-20 mph. He drove right into a 2 ft ditch, and kept those logs going off road into the woods.

I was probably 9yrs old, but fkn sold......


The highest density of lifted diesel douche-mobiles that do nothing, would have to be Wasilla Alaska.

One of my friends runs a diff shop here in Tucson. When I acquired my second 4 x 4 Suburban, an 87, he wouldn't go four wheeling with me till I switched out my GM governor lock in the rear axle. Called it a grenade waiting to happen. The "gov" lock engages when one tire spins 120 rpm faster than the other for slinging a pawl that engages a clutch system, which then causes a cam plate to ramp against a side gear, compressing the disc pack. If someone comes off the side of the road and one tire hits dry pavement with some acceleration the result slam to the system could blow up the unit. Having been in business for decades he has seen enough to know. I installed a 76 full float axle with a dyneer no spin aka detroit locker which is a diff/axle combo and was all set to go.



I liked the comment about the rig with double lockers with a mind of its own. I can believe it!

First understand that locking differentials means that both wheels on that axle will both have the same power applied to them and both will spin at the same speed which does not allow the vehicle to steer around a curve properly, vs an open differential or a positraction type differential that allows the wheels to turn at different speeds therefore allowing you to steer the vehicle around a curve.

Auto locking differentials, like a Detroit Locker, are good units if installed in the rear and are used in an offroad vehicle, or a drag racer in the rear. These same auto locking units will get you hurt in Ice and snow because they will lock without warning at a bad time and now you are fishtailing the rear end of the truck. Even worse is having auto locking differentials in the front. If you hit ice and snow in one of these you will not be able to maintain control and off in the ditch you go, plus you cannot steer a vehicle safely on the highway with the front differential locked. A limited slip differential is an option especially in the front but they do not provide the positive power to all the wheels a locking differential provides.

To overcome these problems and still have all 4 wheels providing power in offroad situations but still able to drive the vehicle on the highway you need Selectable Locking Differentials. These are air powered, electric powered or mechanically engaged (cables) and allow the vehicle to travel with open differentials on the highway with the good highway manors that open differentials provide but the user can select to lock one or both of the differentials if needed. Examples would be locking them to get out of a ditch during a snow storm, taking the vehicle thru a muddy field to check on the cows or in any other offroad situation where you need more traction. They are to be used sparingly and only when moving forward is more important than steering.

With both systems installed in the front and rear you have true 4wheel drive where all wheels have power but with the selectable units you control when they engage therefore allow use both on and off the road.

All Wheel Drive is a totally different animal in that the center has a differential that shifts power between the front and rear as needed plus the differentials in the axles have traction devices to allow power to switch between the two wheels on that axle so that the wheels can turn at different speeds which allow them to be used on the highway. Think Subaru, Audi, etc. This system is not considered by many to be true 4wheel drive because at any one time power may not be available to one of the wheels and therefore does not provide the maximum traction you would get with having them locked but you can steer the thing.

Now my 2002 Ford Super duty came with a 4WD system that had a positraction rear differential and an open front differential. So even though it is called 4WD it was at best 3WD when the positraction in the rear worked, which was seldom and not for long (it failed) because the best it would ever do is provide power to 3 of the wheels at a time. I replaced the rear differential with an ARB Air Locking Selectable and removed the open differential in the front and also added a ARB Selectable differential there giving me the option of having all 4 wheels with an equal amount of power at my discretion. So my Super Duty is what many would call a "Real 4WD" vehicle.

Sorry to be so long winded, but there is a lot of confusion with AWD, 4WD, Auto Locking, Selectable Locking, Center Differential, Locking Center Differential, Full time 4WD, Part Time 4WD, and I hope I have not confused things too much.

Next time he gets off on telling you about his real 4 wd just tell him it's ok but you have a real pickup not one made for midgets and half wits maybe he'll get the message then again he may stay in half wit mode.

Our Toyota Highlander is like that. However, it does have a real 4x4 that you can lock in for tough spots. It disengages at about 25 mph, though, and you're back to AWD.

Simple enough...if it has a transfer case it qualifies, if it doesn't it is a soft-roader.


Personally, I am over flogging around paddocks and feeling like a half opened pocket knife...I want comfort and I don't give a flying fuck what any other thinks of my choice.

I hate to admit it, but the Ram(fiat) 2500 Power Wagon might be the biggest, baddest , true 4x4 their is. Lockers front & rear like the Jeep Rubicon, but bigger axles. Power(minus points) front swaybar disconnects(plus points).
A deep reduction transfer case(with gears) like the Rubicon.

The Rubicon-medium duty, trail ready.
The Powerwagon- heavy duty a hook it to what ever the tires will grab.

Both gas suckers in the class, but outclassing nearly anything off road. Options we only wished for in the 70s or, anytime.

Excellent post.

2 of the best 4 wd vehicles I was ever around was IH scout and my old keep honcho. Both had identical drive train except engine Dana 44 front and rear Dana 20 transfer case
Those would go through places I couldn’t believe

not sure my old '88 4Runner is a real 4x4 or not but for a lot of years, it has gone through some heavy [bleep], and never gotten stuck yet. Sand, swamp, mud, crossing creeks and open Florida prairie. Takes a licking, keeps on ticking.

When you turn, the outside wheel has to go farther than the inside. That means something has to slip. On ice, both of them can slip as they're pushed by the rears. It feels like they're going off 90 degrees from each other. I have a Polaris RZR. Admittedly it's not the road vehicle we're talking about here but the 4x4 principles are the same. On slick roads when the front is locked up, sometimes it will keep going straight when you turn because the locked rears have more traction and keep pushing it forward. The light weight fronts sometimes don't have enough traction to horse it sideways to overcome the heavier rears.

^^^^^^^^^ and a lot of trucks have ABS inspired rear wheel braking as opposed to a locking differential.

I did a bunch of work to my hunting truck, a 92 Toyota , but the biggest thing any 4x4 can benefit from is lockers front and rear. I went with ARB air lockers and an on-board compressor. It also got a 4" lift and better springs in back, which leveled it out with a canopy since Toyota springs blow. Taller tires and aluminum wheels totaled 6" of lift. It will really crawl all locked up. It's flat scary where a locked 4x4 can go. places you realize you don't have the skillset to be. I once straddled a washout that dirtbikes had started and winter rains had carved to about 8' deep. It was on a steep-ass road on top of that, and let me tell you if it had slipped into that crevasse on one side it would have been holy hell dragging it out, with lots of body damage. Went right up without slipping a tire.

Made a believer out of me, lockers are THE SCHIT.

Zr2 has a locking front diff, turning both front tires when locked.
Z71 has a open front diff, meaning only one front wheel at a time pulls when in 4wd. Also, it picks the wheel with the least traction, leaving you spinning in a bad situation.

Anyone spending almost 50 k on a Phugging Chevy Colorado needs to have their head examined. Thats the base price on a ZR2 .

What lift did you go with? I went Old Man Emu 2” with 235/85R16’s.
Mine has the E-Locker on the rear from the factory. It’s got me out of anywhere I needed out of but still wish it had a front locker. ARB bumper with a 12,000lb winch so not too worried about getting stuck.

I call that maximum slip diff !

Every GM 4x4 I've owned since the '80 K10 shorty, came with what GM calls a locking rear and all worked fairly well, provided they had decent tires on them.

While I haven't done much "adventuring" with them, neither did any of them ever get stuck in snow or mud. The '80 came to me used, with "car tires" on it. Replaced them with Firestones that resembled BFG T/As back in the 80s, world of difference. Made it through some impressive amounts of snow with that truck. Hunting buddy had an '81 Chevy, also with the rear locker, which also got around pretty well.

He finally traded that with over 200K miles, on a new Chevy 4x4. The dealer he bought it from, didn't order their trucks with the rear locker option at the time, like most other Chevy dealers around here did. Said he didn't think having a rear locker was a big deal?

First deer season, he backed up into a snow covered field to retrieve his buck and got stuck. One rear wheel dropped off the end of the sluice pipe at the field entrance. Twisted the truck enough, that one front wheel had no weight on it, so she just sat there and spun in FWD. Needed a bit of a pull to get it out onto the dirt road. Told him he might as well be driving a Nash, without at least a rear locker? He didn't keep that one long, replaced it with another new truck w/locker.

Lockers all around are the cat's ass if you're gonna regularly be going off road. Otherwise, just the rear locker is usually enough? Has been for me, so far for normal road use. Have an old beat to hell Bronco II at hunting camp for off road use. Regular little mountain goat in the woods. Locking hubs, five speed and it stays in FWD low at all times. Haven't had that stuck yet, either.

I have a power wagon with 456 rear end, and a rubicon with a 410 rear end, when you lock all in and disconnect sway bars in deep mud with ditches, it’s pretty much unstoppable, plus they will both pull much more than what spec’s say, in short pulls, winch on front of both are a must.