I have a 1999 F350 5.4 4x4 and need some advice with lockers. I am not familiar with dealing with axles and that is why i took my truck to a shop to install the 4.56 gears. I do not do alot of mudding, but I do tend to go offroad alot needing my 4x4. My question is should I entertain getting a locker or lockers. It seems like my D50 up front may have a limited slip or something in it since it does not like to turn when on concrete with the 4x4 engaged but i don't know. My rear definetely does not have limited slip because my truck loses its *** when it slightly wet on the road and a little too much accelerator is given.

My friend who is a jeep guy says if i get a locker to put it in the front axle only, for reasons I do not understand. I have been considering a rear locker so that my truck will get more traction while in 2wd when the roads are slick and I am towing. My friend also says that the locker will lock and unlock going down the road periodically and sometimes can pull the vehicle pretty hard. I personally do not like the sound of that. What advice do yall have regarding this. Should I entertain the locker or save my money since a locker is more of an offroaders cup of tea.

 

From the factory, you may have had a limited slip, but not a locker.

When they changed gears, they didn't talk to you about the limited slip condition etc?

First, no 4x4 wants to turn well on hard surfaces. You should not have 4x4 engaged unless you are on limited traction surfaces. In a turn, each wheel is going to travel a different distance. In 4x4, the front and rear axles are locked together and the drivetrain will wind up--literally--as the forces build up to the point where the tires slip or something breaks.

As for the vehicle slipping sideways--"losing it's ***" as you say--that is exactly what happens when BOTH rear wheels spin, as they will with a limited slip (if it's working properly) or locker.

You should find your axle code and post it--my guess is you have a limited slip.

As for your Jeep buddy: A locker in the front is an off-road thing only. It is very hard to steer with the front axle locked. As for the rear axle, see above, but as far as it locking and unlocking while running down the road--it's not supposed to. Most lockers are made to lock up under power, not in steady state running. Selectable lockers (air or electric, "ARB" etc) can engage when you hit the switch, but if you are on a straight, it won't matter much but it is not advisable to run long distances with a locked diff on the road. If his is pulling his vehicle one way or the other, he needs to have that looked at.

As for advice, post your axle codes and we can go from there.

 

I thought lockers used spring loaded clutches to lock both sides together? Only when the variations between the two sides become great enough to overcome the springs do the gears pop apart to allow some temporary differentiation. Otherwise, the two sides are always locked together.

So you can see why it's a bad idea to install a locker on the front, where you want to steer. You don't want to be constantly fighting and popping the locker while trying to go through a corner. For the front, you can install something like a Torsen or Quaife differential, which allow smoother engagements/releases.

 

The axle code is 41.

I have always thought that my truck does a one wheel peel when it starts to cut tires but I see what you are saying about the truck fish tailing when both wheels begin to spin and lose traction.

Regarding my friend with the jeep. He has detroit lockers front and rear and told me that the locker had either locked or unlocked one time going down the highway which pulled him into the lane next to him. I amounted this to the jeep being short, light, and maybe also because of the oversized tires and steep gears he has.

 

You are correct about most lockers using the spring/clutch/ramp thing, depending on model. In cornering, the springs allow the axle to unlock and provide differential action. However, if you apply power, they lock up. My comment is only partially correct in the prior post as they are "locked" in "normal" running, coming unlocked when the cornering forces overcome the springs--which they will unless you apply power in the corner.

Detroits are very noticable on the street:

Detroit locker, Street manners in wet weather?

Detroit Locker on the street???? - Chevelle Tech

Detroit Locker for the street? - Ford Muscle Forums : Ford Muscle Cars Tech Forum

Several stories about pulling on one way or the other on the highway.

Read down the page about problems with the Detroit in a drag racing environment. It's ancient history, but the Detroit design is the same, so weak springs could still cause an issue:

Ford Thunderbolt Reunion - '64 Fairlane Thunderbolt 45th Anniversary Celebration - Hot Rod Magazine

 

What you said here got me to thinking about all wheel drive vehicles and how they would drive. Is an AWD car such as a subaru that different from our 4x4 trucks that they do not bind up?

 

Here's my experience with my E4WD Aerostar. It is full time 4wd, with a front open differential, a rear stock clutch type LSD, and a center differential that can be locked with an electromagnetic clutch when the E4WD computer senses slippage in either the front or rear wheels.

To keep the 4 wheels from binding in a 4wd vehicle, all 3 differentials should be open. But that can be just as bad as 2wd if just one wheel gets stuck in a poor traction spot; it will spin uselessly. So some kind of locking mechanism is needed to redirect some of the engine power to the other non-spinning wheels. With the full time AWD systems, some kind of computer reads the wheel speeds and decides when to lock one or more of the differentials. With the part time 4wd vehicles, you the driver makes that decision. You just have to remember when to disengage it based on the conditions.

Once I allowed the front tires of my Aerostar to get much more worn out than the rears (forgot to rotate them). It confused the E4WD computer, which started to lock the front and rear together while I was in a dry parking lot. It caused really bad bind, which I think may have resulted in the forcible release of the center clutch. I pulled the computer to stop that, leaving the front and center differentials open.

 

Yes, AWD systems are set up to allow differential action between front/rear, as well as side to side. They use various locking methods for low traction situations, including using the brakes to stop a spinning wheel and transfer torque to the other side. This is just an updated version of the old farm tractor with two brake pedals, one for each side....

 

I got a Detroit Locker on the rear of my 95 Bronco. It's been on there for at least 12 years. As far as pulling to the side. Thats only if one tire is low on air.
Fish tailing never.
I got a Lock-Rite in the front of my 2000 Superduty. Yes it can be hard to steer in 4WD.
You should look in to a selectable Locker. It locks and unlocks at the flip of a switch.

 

Heres a selectable locker from ARB.
ARB Air Locker Benefits - YouTube

 

I think I am going to leave it as is for now. The truck does just fine offroad and I really want to avoid running air lines for a selectable locker at the time being. Can anyone identify my axle code 41. Truck is a 1999 F350 5.4. I do not think it has limited slip because from my research the limited slips axle code has an L in it. The codes are also hard to decifer because from my research 41 also means my truck might have had 4.10 gears, but they were 3.73 before I went to 4.56s. Any help would be appreciated.

 

Hhhm, this here says 3.73 open....

https://www.ford-trucks.com/forums/3...axle-code.html

 

I have a mini spool in the front of my 84 3/4 ton with no ill effects when i unlock my hubs