Detroit & 4wd on asphalt ?? Problem ??

I now running a Detroit locker in the rear. Works great in 2wd; however if I put it in 4wd on the asphalt any time I turn the wheel no mater how slightly the vehicle seems to bind up even with the front open. The rig stops unless you really give it some gas and the rear leafs and shackles completly open up & kick the ass end all the way up. It also becomes very difficult to dissengage the Xfer Case when this happens. It seems to be OK on dirt though. I was welded before and never seemed to have this problem. Any thoughts or Ideas why it is doing this or if it normal??

What transfercase are you running?

Obviously, a 231 shouldn't be run in 4WD on asphalt under any conditions.

all locker manufacturers state that locked vechicles bind the center diff much quicker than normal, even if the front is open. Why it didn't when you were welded though I don't know.

Christopher said:

I now running a Detroit locker in the rear. Works great in 2wd; however if I put it in 4wd on the asphalt any time I turn the wheel no mater how slightly the vehicle seems to bind up even with the front open. The rig stops unless you really give it some gas and the rear leafs and shackles completly open up & kick the ass end all the way up. It also becomes very difficult to dissengage the Xfer Case when this happens. It seems to be OK on dirt though. I was welded before and never seemed to have this problem. Any thoughts or Ideas why it is doing this or if it normal??

Click to expand...

Yup, that's what it will do. Chris, to run 4wd on the street, even without a locker, takes a full-time 4wd setup which includes a center differential. Part-time 4wd, like in an NP231 or AtlasII, is meant only for off road.

Got the driveline finally?

Got a driveline, not the driveline. I realize it is not for use on asphalt, I'm just trying to figure out why it is doing it now and never did it before? Everything is exactly the same except for a Detroit in the rear instead of a Lincoln.

Because when you turn with a Detroit or similar-behaving patents, you only have one-wheel-drive, at the inner wheel of the turn.

The whole thing can be explained by a simple drawing of the vehicle from above. While turning, each wheel follows a cirle arc, all with different diameters, but with the same center. If you draw one arc through the middle of the front axle, and one at the rear, the distance travelled along this arc will be the average distance travelled for both wheels of that axle, i.e. what an open differential outputs. Driveline binding comes from that this circle at the rear axle has a smaller diameter than the one for the front, i.e. the rear wheels combined turns slower than the fronts combined, so one wheel has to slip a little to make the turn (since the NP231 will keep both diffs rotating at the same speed).

Now, when you get a Detroit and start turning, forget the arc in center of the rear axle, your transfer case is now trying to keep the speed of your inner rear wheel and the fronts combined the same. Bigger problem, see?

I'm guessing the welded rear is maybe better than an open diff in this regard, because then both wheels have to slip quite a bit to allow the car to turn at all, and they don't care which one slips the most, so if imagine the outer wheel don't slip at all will cut your drivetrain some slack.

Don't know if that was even remotely understandable, but make a drawing, it's actually really simple.

why would the Detroit in the rear make any difference in this case?

A Detroit rear only locks the rear wheels together... If it would bind in 4x4 then it would bind in 2x4...

The binding has to be coming from the Xfer case not letting the front and rear turn at different rates...

I say this because I have a Detroit in the rear and never have binding problems (Unless I leave it in 4WD and drive on pavement)

87 XJ
242 Xfer case

You're worrying about something that is meaningless. Maybe the pavement conditions were different. Maybe the detroit does behave differently. So what? If you want to break expensive parts, keep it in 4wd on the street and see what blows up first. Or be smart and just keep it in 2wd under high traction conditions and don't worry about it.
mattk

Had a similar problem when I was a kid....


Me) Hey dad, my head hurts when I hit it on this brick....


Dad) Don't do that....



Problem solved