Home Forums Gear Hunting Trucks and Four-Wheel Drives Mentoring needed on Jeep differential upgrade....

Guys, I am doing a resto on a civilianized M-38. I have a powr-lok limited slip diff in the rear (Dana 44). I have two choices for the Dana 25 front: powertrax "lock-right" full mechanical locker or powr-lok limited slip.

This is not a rock-crawling machine. I just want to make sure I have outstand off-road traction capability if I need it. I imagine limited slips front and rear are a pretty good combo, but then again the idea of a full mechanical lock capability up front has some merit.

What say you experts?

Jordan

What you're really going to need is power steering if you put in a full locker.

I have a saginaw set up. Are you saying with a mechanical like the lock-right, steering would be that difficult??

Putting a lock rite in the front, you will notice a slight difference in steering, nothing to worry about. The locker will disengage when cornering, just like it is designed to do. I had a 57 CJ-5, dana 44 rear, 25 front with a powerlock (4 pinion) posi in the front and open in the rear. It went everywhere I wanted it to and then some.
Either one will serve you well.

My experience was much different with the lockrite in a CJ5, the steering was complicated off road, it would pull the wheel or try to pull the wheel out of your hands, and was difficult to climb out of rutted roads. It was "entertaining" at highway speeds on the road when the hubs were locked. Everyone told me at the time to just unlock the hubs on the road. Well that turned out to be silly advise because then the jeep is only two wheel drive on pavement.

In my opinion there is only one complete solution to the front locker situation. Its the selectable on off locker with an open diff for on road use. Anything else is a compromise that makes use on the road annoying at the least, and scary/dangerous at the worst. I would choose a Limited slip over a full locker for the front, but that's just me. The rear locker on icy roads is entertaining enough!

It only takes one time at 50mph hitting ice or snow with that sub 100" wheelbase to see the situation

Thanks for the advise everyone. I just scored a Dana 25 powr-lok which should drop right in (as opposed to the bastardized version I was trying to make fit). I've got a full-floating 30 spline axle in the rear and I just may pop out the powr-lok in the rear and put in a selectable locker. That would give me full-lock-up capability in the rear and limited slip in the front---which should be enough for an old guy like me.

As always I look at things differently.

Stay away from gear clutch driven LSDs in the front axle. They don't allow the front tires to turn at different speeds (cornering) without dragging. The force needed to overcome their resistance can be enough to break traction and have the rig "snow-plow" straight ahead rather than turn.

Gear driven LSDs and automatic lockers up front, IF PROPERLY INSTALLED, work well because the springs separate the 2 halves unless there is power coming from the drive shaft. That makes them invisible in 2WD whether the hubs are locked or not.

For a mild rig, I'd go with a TrueTrac gear driven limited slip in the front. For something more serious, I'd go with a Detroit locker. For the rear, it's Detroit or nothing. I've owned rigs with factory limited slips and factory manual lockers and I've been nothing but disappointed in them.

Detroit vs Lok Rite ... Lok Rites are kind of rude and rough in operation. While I was running the Detroit in my TJ, one of my wheelin' buddies was running Lok Rites front and rear in his Toyota. It'd GO, functionally they're good, but it did a lot more popping and banging as it engaged and disengaged than I was used to.

Tom

Maybe I'm wrong, but I think TOM meant stay away from clutch-based LSD. Otherwise, a True Trac for mild/medium stuff and Detroits for wild stuff.

Yep, that's what I meant. Good catch. Thanks! Corrected above.

Tom

There is a sort of a skill needed to drive a short wheelbase vehicle with any locker. I have an Aussie Locker in my land cruiser, and I had a Detroit in my CJ5.

Both can get you in trouble on paved icy roads and both worked equally well off road. I agree the Detroit has some smoother characteristics when driven hard on pavement but it will still grab and screech a tire now and again.

With either one the key is coasting or maintaing speed in any turn. Any hard acceleration in a turn and the "lock up" will be felt and heard. In the front I had a Detroit Tru track in the CJ, it worked as well as I hoped it would, but it's no locker off road.

My Cruiser is still an open diff. I'm not sure what I'm gonna do, hopefully and ox locker will be made for is eventually ( mechanical cable actuated locker) otherwise I'll probably just leave it open. The experiences I've had with a locker in the front on highway in 4X4 with icy snowy conditions have been all bad. I just don't care for that Performance. Seeing my life pass before my eyes is not part of the experience I need.

I do think that the Ox Locker is the ticket for flawless, bullet proof, dependable lockers today. I don't have one, but those I've seen used are the best game in town.

Thanks all. I appreciate the expertise.

JJ, what about the toyota E-locker for your Landcrusier, or maybe an ARB? I have a 93 Toyota PU and an 87 4rnr I'm considering one or the other for.

I am running Spartans in the front and rear of my XJ. They are barely noticeable if you have a clue about how to drive them on pavement. If you like jackrabbit starts, you will chirp a tire if you are turning. The front is NOT designed to be driven on the pavement in 4LO, but its acceptable in 4HI at any SANE speed on snow an ice. Just remember that it is locked when you are applying power and if you don't remember, it will remind you pretty quickly...

If it was me I would of looked for a Dana 30 out of a 77 or newer and got some disc brakes. Than you have allot more choices for gears and lockers. And it bolts right in.