Locker In Front Or Back?

IMHO the ideal setup would be to have selectable lockers in both axles with the ability to chose either or both on demand. When not engaged the axles should be Open. I have no use what so ever for a Limited Slip type rear end in a short wheel base vehicle. I like being able to turn.

In my own Willys CJ-2A with CJ-5 frame and suspension. I have a Dana 44 30 spline flanged with an Eaton E-Locker controlled from the Shift knob (I built my own shift knob with a switch for Locker control) I currently have a Dana 25 Open front axle which down the road will be replaced with a Narrowed Dana 44 or Narrowed Dana 30 that also sports an Eaton E-Locker. I need it on the road and the Aluiminum Hard top finished before I go that way.

 

Limited slip allows "some" difference in wheel turning rates before engaging, yes? This is compared to a "locked" axle where both wheels turn the same.

 

Right, I've never heard of a traction device on the rear axle causing trouble with steering. Supposedly a rear locker can make control trouble in icy conditions ... no personal experience.

I believe the rear axle is the first choice for traction devices because of the steering issue, and because of the weight transfer. When you climb a hill, or accelerate, much of the weight transfers to the rear axle ... and that's where you need traction. So that's the axle where added traction will make the most difference.

 

My VW Vanagon (Syncro) has a vacuum selectable locker in the transaxle that locks the rear drive axles together. When engaged on a solid surface, the van definitely wants to go straight ahead, and turning is noticably more effort, with lots of front tire scrubbing. A limited slip may be slightly noticable while turning, but to a much lesser degree than a locker, depending on the lockup.
For a vehicle driven on the street (including a Jeep), a limited slip would be more desirable for daily use, though selectable lockers have their place because they are only used when needed off road.
-Donny

 

Recently a friend brought up question to me.
Which is best ? Front traction device vs, rear traction device.
He tells me that some well respected authoritative wheelers (no names given; you know who you are) are claiming front traction devices should be used if only one is available.
We looked at each other and shook our heads in disapproval to that ridiculous claim.

Rear traction is virtually always best.
Fact is that Willys went through this exact same dilemma and those lessons were learned very many years ago.

For beginners...Remember when the MB and GPW sported a 23-2 rear axle assembly ?
Both front D25 and rear D23-2 differentials are open but more importantly both are identical concerning strength of internal components.
As you all know the 23-2 has a bad habit of frequently breaking while the front encounters very few breakage issues.
That alone tells us that the rear axle assembly encounters much greater strain than the front assembly.
So right after WW II, Willys increased the strength of the rear axles.

By the the mid 1950's Spicer began to engineer and develop traction enhancement devices.
To be more specific Spicer, the Military and Willys Motors finally settled upon the Powr Lok differentials.
By late year 1956 the rear Dana 44 Powr Lok became certified as Willys Approved Special Equipment.
Note that the original traction device was built for the rear axle only and not available for the front.
It was not until the early 1960's when front model 25 Powr Lok differentials first became available.
And very few will ever encounter a D-25 Powr Lok that is dated from the 1960's.

If we do not recall our history we may be doomed to repeat the lessons of the past !

 

Great comment Glenn. Although I have never been to Florida, I was also young, dumb, and fearless when I bought a new 69 CJ5. And pointed at stuff that now makes me cringe. WCP

 

IMO, installing any type of automatic traction device in the front axle pretty much eliminates using 4x4 mode on-road in ice or snow, assuming of course you actually desire to stay on the road. For those that never see those slippery conditions, you can just lock out the front hubs when you don't need 4x4 and all is well with a front axle locker or limited slip. Personally, the only traction device I want in a front axle is a selectable that can be run like an open differential when desired and as noted, I don't think those are an option with a D27. Also as noted above, I'm another one who will not spend any money rebuilding or enhancing a D25 or D27. The axle shafts in those are barely adequate for normal operation with a stock drivetrain and tires. Much better to spend those funds on a bolt-in D30 for which you can buy just about anything you want.

Speaking (ok typing) from personal experience with a Detroit Locker in the rear of my 3B, steering is impacted in a VERY big way, especially on hard surface roads. That unit will not unlock as long as there is a sufficient load on it. So, say you go into a corner maybe a bit too fast for your liking and the unit is locked. And then you back off on the throttle and it unlocks. The steering correction you were unwittingly making going into that corner with the locked rear instantaneously disappears and those unannounced, unwanted lane changes are VERY real. Perhaps that isn't a problem with either 134 and maybe not even with the 225, but it is certainly a problem with any sort of healthy V8 in a short wheelbase Jeep.

 

The locker in the rear of my 71 affected steering, it wanted to push. A simple lift of the throttle allowed it to unlock and turn into the corner.

 

And the fact that it will not go faster than 50 mph?

 

I had the V-6, quite healthy with a regular locker. It was in sweeping turns that it would push, a little lift and it was all good.

 

Easiest way to tell without opening it up is the power-lok probably still works, and the trac-loc probably acts more like an open diff... lol. Just pop the cover off and take a photo. It probably needs an oil change anyways.