The front differential is open. The binding issue, or problem with 4wd on hard-packed, or non-slippery surfaces that is, comes from binding in the transfer case when turns are negotiated and the rate of rotation in the transfer case as it relates to the front driveshaft differentiates from that in the rear driveshaft, causing a binding in the transfer case, possibly resulting in a stretched or broken transfer case chain.

A front locker affects the front differential only, locking the pumpkin up so both front axles rotate equally under all conditions. This has no effect on the power differential aspect of the transfer case.