Front differential

[sparks57]

Ok, well last time I asked about limited slips no body replied, so I did some research and decided the Dana Powr-Lok is what I will get for the rear end.



Now what about the front? I keep hearing about people putting lockers and limited slips in the front... but why?



It seems to me that the front is locked, I was always told never to drive in 4 wheel drive on pavement because you could snap the axles... That to me means that the front is already a locked unit when engaged... is that true? If so, why would anyone put an aftermarket locker in?



I am assuming that a limited slip unit could be put in front to allow better turning while in 4 wheel drive.



I added this here so the guys who never go to the off-roading forum could get exposed to this... but I will post this over there too.



Thanks for any replies.

 

[y-knot]

The font has a normal (non locker or limited slip) differential, and it will act just as the back axle would, giving all it's power to the wheel with the least amount of traction. The reason you don't run in 4wd on dry pavements because the transfer case mechanically locks the front axle and the rear axle together. These units, when turning turn at a different rate, I. E. the front axle has it's own turning radius from the rear axle, and the two wheels on each axle have different turning radius's from each other, which means they are all turning at a different rate from each other during a turn. So even if you have a "open" differential on each axle, the two wheels that aren't driven are turning at there own rate, and the driven wheels, which are now locked together by the transfer case, are each turning at a different rate, and this is what makes it had on the drive line. Since everything is mechanically locked together, something has to give. If you were on snow, grass, dirt, the stress is so much, there is areas for this "stress" to relieve itself, but on pavement, concrete, ect the tire get a much better grip and this "stress" can not be relieved as easily, resulting in much higher levels is stress on the drive line, and the transfer case is the most likely target for this relief (usually the chain inside breaks).

 

[sparks57]

Huh, that makes sense. Thanks.



I was thinking for offroad purposes that something like the Detroit Locker would be good for the front because of the locking hubs, and then an ARB air locker for the back, or a limited slip.

 

[Midnite]

If you drive the truck daily, I would *not* recommend a detroit locker up front. At the very least it would be dangerous on wet and icy roads.



I actually did the powr-lok in my rear diff, and absolutely love it. The local 4x4 shop that did it set it up very tight, so now even on icy roads I rarely have to engage 4wd. You should be very happy with a powr-lok in the back.



If you off-road enough to need something up front, I'd do an ARB.



Mike

 

[sparks57]

I thought a detroit would be fine because of the lock out hubs???

 

[Midnite]

Well yeah, if you unlock the front hubs you would have no problems. I guess I'm thinking of my own driving habits--I tend to leave the hubs locked in almost all winter up here, and then just engage/disengage 4wd via the transfer case as needed. If you normally leave the hubs unlocked untill you actually need 4wd, then I don't think you'd have any problems with a locker up front.



Mike

 

[sparks57]

Good point, I never thought of that. I leave my hubs in during the winter also...



Well, back to the drawing board!



I am thinking maybe air locker up front and powr-lock in back now... at least for today!

 

[y-knot]

I couldn't agree more... In the front the only real choice would be an ARB or an electric Detroit locker, Both are great and in the $800 range. In the back the two I just mentioned would be my first choice, but there are many options in the rear. I have had the Detroit locker before, and it does work but is rough on the street, heck it's been around since the 50's. I just put a ABURN pro series in a ford pre-runner I built, It great off road, and not so harsh on the street. There are a few that will run the "Lincoln locker" but It not the wisest choice, but the cheapest option, I just couldn't do it to a truck. Look around an go with a name brand, from a responsible store.

 

[Scot]

I would go for something that you can unlock from the cab. Posi front and rear is great unless you want to turn. It just keeps trying to go straight and plows the front wheels.

 

[skobylenski]

You guys are talking about leaving your hubs locked all winter and then just engaging-disengaging the transfer case. I've noticed that in my truck disengaging the transfer case is near impossable to do when stopped, and just as hard when rolling down the road (yes, I do reach all the way over there when on the road). Is there something wrong here, or are these things just REALLY hard to shift? It doesn't seem to matter whether or not the hubs are locked.



A note on leaving the hubs locked - premature wear. Yes, it's a pain in the ass to have to lock and unlock all the time, but it really leads to a lot of excessice wear, especially if you travel highway speeds for any distance. Just my $. 02 on that subject.



Scott

 

[sparks57]

I only leave my hubs in when there is snow on the ground, and never on highway trips.



But, yeah the t-case can be a real pain to shift sometimes, if your axles are bound at all... the shifter will be really stiff.



If you have a stiff shifter, try stopping and throwing the truck in reverse, back up a few feet and try shifting again.



Or, if you are in 4 wheel drive and you just made a left turn, try turning a little to the right and it will release the bind.

 

[benefits]

what i do is accellerate a little bit and then push on the shifter as i let off the throttle and that small time that there is no pressure it will easily shift.