You've heard us harp on the subject for years without once changing our tune; running an automatic locker in therear of a short-wheelbase Jeep can make for a miserable on-road driving experience. An automatic locker functions very simply. It's locked when power is applied to the axles and unlocked when no power is applied. That means every time you get on and off the gas, the locker locks and unlocks. The handling drawbacks manifest themselves when this happens in the middle of a turn, changing lanes, or negotiating curvy sections of road. On some Jeeps with supple suspensions, especially link-type suspensions, the locker actuation can cause the Jeep to change lanes or shoot violently to one side or the other. It's something the average enthusiast will become accustomed to rather quickly, but for us the acid test is always, "would I toss the keys to a non-enthusiast, my wife, or a valet?"
We wanted to see if we could take steps to improve these handling drawbacks. Granted, our stock-height, leaf-sprung '89 Wrangler test vehicle is a best case scenario for the auto locker, while the worst-case would be a TJ with a manual transmission, tall short-arm suspension, and larger tires.
Since we can't in good conscience recommend installing a locker of any type in a stock Dana 35 rear axle, we called Superior Axle & Gear for its Super 35 kit. This kit includes an Eaton Detroit Locker, Superior's superb 30-spline, 1.31-inch alloy axleshafts (stock Dana 35 is 27-spline, 1.16-inch), and a full installation kit. This would ensure we don't suffer any breakage during our testing. So after all our efforts are we satisfied? Nope. Although it helped a little, we still wouldn't toss the keys to a novice. It's still better to run a selectable locker or spool if you're concerned with street handling.