WJ 4.7 V8 D44a auto locker, quadra trac 2

[octanepwr]

Thinking of fitting a rear auto locker in a project and want to confirm my research and get feedback from those who have them. Truck won't be daily driven but will see some road km.

1) With quadra trac 2 I can fit an auto locker into the rear on the 4.7 with no issues as it has open diff and the gearbox/transfer case won't have any issues?

However interestingly I found on the 2.7 CRD if fit one it will go into limp mode as the merc gearbox doesn't handle the way the auto locker works?

2) Installing Lokka doesnt require diff specialist assuming ring and pinion already satisfactorily set up, bearings are ok, etc. Just put the shims and bearing caps back in exact spot they came from?

3) Mixed views about road manners - clunking noises and wheel chirping
More tail happy in the wet, corners sound manageable though?
Offroad, auto locker seem superior to vari-lock, except perhaps certain side-hill situations where you want more difference in wheel speed?

4) Seems to be lots of talk of trussing D44a when locked on US forums, given they are aluminium.
Anyone experienced cracking/bending a D44a housing, whether locked or unlocked?
I am not keen on the hassles of trussing, so if fitting a locker will likely break my diff then I am out!

5) If I do go down this route for the project I will probably swap a whole vari-lock housing into the front given quadra trac 2 open each end - I know swapping centre only doesn't work as need axles also. I don't like front auto lockers and selectable ones are almost worth as much as the truck.

Please correct anything above and be great to hear other user D44a auto locker experience?

Thanks

[Grippy]

You will be fine, it's only the housing that's aluminium, the rest is a little beafier than the original 44 from memory. Pretty easy job from memory.
A bloke in our club runs a wk1 with rear lunchbox locker and loves it, reckons it behaves itself quite well and he takes his rig on some tough obstacles!

[Deezelweazel]

You shouldn't have any difficulties with an auto locker, some 2.7 have a different amount of friction modiefier in them- the more modifier, the better the street manners, less friction modifier, the more aggressive the locker acts.
Since the speed is constantly checked via the tone rings the ABS system should not interfere. AS you know you can lock the rear axle with the ARB RD226 - also 100%, no interference with the ABS system or limping.
I need to verify if ABS is shut down completly in 4low.

I wanted to install as a first measurement a solid diff cover- not that flimsy stamped steel one. But it seems it must be fabricated. I heard no good stories about the aluminum diff, loose axle shaft tubes and alike. Trussing it could definetly help.
But it still has the turdy in the front, so with that limitation tire size is restricted 31" when locked. I'll keep it for light off-road purposes.

he, you have difficulties when you are the "rev redline guy"...

[JeanLuke]

Be careful with an autolocker on the 2.7 CRD. They don't play nice together. Here's why...

The NAG1 gearbox does not have an output shaft speed sensor. Rather, the output speed is calculated from the two rear wheel speeds, averaged, multiplied by the diff ratio and then corrected for Lo/Hi range. The ABS module reports this to the TCU.

An autolocker when cornering under power will send the drive to the slower (inside) wheel and allow the outside wheel to ratchet faster. no problem. However, if you lift off the power in a corner, the torque reverses. The faster wheel then becomes the wheel driving the tailshaft and the inside wheel is allowed to ratchet slower.

Under these conditions, the averaged speeds of the two wheels, corrected for diff ratio, is less than the actual tailshaft speed. The TCU then sees this as transmission slip and throws an error - particularly if you are in the "transition" zone of the throttle setting.

Note that a total locker does not have this problem because it either acts as a normal diff or when locked it still reports the correct tailshaft speed.

[octanepwr]

Thanks for replies. Won't be going in 2.7, that was just an interesting fact I found along the way and that was a very good explanation JeanLuke

Still keen to hear who has had them in a 4.7 rear and anyone who broke a d44a

DeezelWeasel autolockers don't need friction modifier? Not talking about varilocks.
Also I would never put one in the front. Front auto lockers are bad in my experience. 31s won't get you very far where I am.
And if you think I ever wanted to Rev my jeep that high, I've already explained that was never intentional, you must be pretty thick mate or bored as with too much time on your hands to keep going on about it so take the unhelpful comments on that somewhere else

[Deezelweazel]

Oh, I'm so sorry I couldn't help you.
You never make mistakes, do ya?

The Dana 30 is a piece of crap for anything bigger than 31". I'm very careful to lock it. It simply can not handle a lot of extra stress. I do have had a nice selection of sheared front axles of the short side. A short snapping noise- done.
Always at the necked down part next to the spline.
If you were wheeling (locked) with bigger tires than 31" - you have been lucky so far. Do yourself a favour and get at least the shorter axle of the front as a spare.
The 44a is ok for street applications as long as both tires are planted to the road evenly. SRTs have no probs. Even with the thicker diff housing, it is sensitive to bending. You will recognize when the locker will not engage properly. So no jumping and hard coming down on the rear axle.

I do run ARB's front and rear.

[Adrian D]

Originally Posted by Deezelweazel

You shouldn't have any difficulties with an auto locker, some 2.7 have a different amount of friction modiefier in them- the more modifier, the better the street manners, less friction modifier, the more aggressive the locker acts.
Since the speed is constantly checked via the tone rings the ABS system should not interfere. AS you know you can lock the rear axle with the ARB RD226 - also 100%, no interference with the ABS system or limping.
I need to verify if ABS is shut down completly in 4low.

I wanted to install as a first measurement a solid diff cover- not that flimsy stamped steel one. But it seems it must be fabricated. I heard no good stories about the aluminum diff, loose axle shaft tubes and alike. Trussing it could definetly help.
But it still has the turdy in the front, so with that limitation tire size is restricted 31" when locked. I'll keep it for light off-road purposes.

he, you have difficulties when you are the "rev redline guy"...

diyfabparts.com, ironman4x4fab.com both make D44a covers.

The 30 up front is not as weak as people say, thousands of them survive with larger tires and a full case locker will definitely help.

Unless you do stupid stuff you won't have much trouble without a truss and rear cover.
Stupid stuff like trying to back out of this ravine, locked: