Check these things before anything else: Warning, this is a long post
I was so unhappy with it I was about to yank it and switch back to an open diff. The people who have an automatic trans notice it much less than those with a manual trans. I’ve got the manual 5 speed, and it was REALLY noticeable. In addition I’ve got a Ranger, so it’s light in the back end. I had all the same problems you have. If you’ve jacked up the back end off the ground, and done the test they recommend and it passes, then you can be pretty assured your powertrax is working properly. I took of the rear cover to check for wear, and there was none. The powertrax noslip is sensitive to several things: 1) different tire diameters (same sizes, different air pressure can cause problems) 2) worn or loose shocks/ubolts/ujoints/etc.3) the break-in period, and 4) driving habits.
I’ve done quite a few things that have minimized the problems to the point where I can say it’s better than an open diff. What I found was many little things were adding up to make a big problem. Fixing these things made a big difference. The one thing to keep in mind is that the powertrax noslip is very sensitive to which tire is perceived as going slowest. I’ll get into that more further down.
Solutions:First off, the break-in period for me was critical. The locker was so much smoother after 3000 miles were put on it. Do your u-joints. Either way that might help at least a little, maybe a lot. Second, tighten everything up – check for loose swaybars and loose shock mounts. I took my truck to a driveline shop, one that specializes in doing gears and custom driveshafts and stuff for an evaluation. They test drove it and then brought me in back and showed me what they found. Have someone else that you TRUST in the drivers seat, have them pull forward a few feet and slam on the brakes several times, while you are behind the vehicle watching the rear axle. Here’s what I saw: shocks that seemed tight were literally flopping around. U-bolts seemed tight but were loose, and the swaybar was also flopping in the urathane bushings. I went home, took a couple of hours tightening everything up. This all made a big difference. Then I checked air pressure in the tires. I’ve got large oversized tires (31x12.5r15 bfg all terrains), so I was running a lower air pressure to keep the ride quality from being that of an empty cement truck. I increased the air pressure 10psi and that made a huge difference. Powertrax lockers are VERY sensitive to different size tires. With low air pressure, the tires were flexing significantly with weight changes such as those that would occur in a left or right hand turn. I found that even a lane change was causing the tires to “squish” on the outside. That was enough to change the diameter of the tire, causing a change in which tire was perceived as the slowest tire.
I didn’t really think tires would squish that much, but when I was at the driveline shop, they had two guys rock my truck back and fourth. I was amazed at how much the tires flexed. Seriously we’re talking the tire squished an inch or so on each side! I was running around 18-20 psi I think, at the time. With the tire changing so much, the noslip was “hunting” for the slowest wheel constantly, as weight shifted. Minimize the changes and you minimize the effects. Adding air pressure to stop this from happening made a pretty significant difference.
I also adjusted my driving habits – a lot! COASTing through left and right turns makes a huge difference. If the noslip is driving the inside tire when you make a left hand turn, accelerating briskly, several things happen. Weight shifts OFF the inside wheel which is the one driving you through the turn. As you accelerate, the inside tire is also turning somewhat sharply. When a tire is turning sharply, a significant portion of the tire is slipping a little. The wider the tire the more pronounced the slippage. With power to this wheel and weight shifting OFF this wheel, it’s easy for the tire to give more slippage than it otherwise would. You might not even perceive this as spinning, since you may not hear much or any squeal. What happens though is that as soon as it starts to slip, it catches up to the outside tire. The locker locks with the outside tire momentarily, and instantly shifts back to the inside tire which slowed down instantly once power shifted. This total effect going through the turn is experienced as understeering, then oversteering, then understeering again as you feel the power shift from wheel to wheel. You’ll probably also feel/hear the locker engaging the different sides.
When you coast through a turn, you allow the inside wheel to not slip as much, minimizing the effect. When I talk about coasting I don’t mean foot totally off the gas type of coasting. I mean gentle power. I’ve found that the locker, which normally has both wheels locked and under power, can sometimes not want to release a wheel when it’s got a lot of force on it. The meshing gears don’t want to release when you’re on the gas. That’s pretty common when you are making a left hand turn quickly, and let out the clutch fast. To minimize that, As I pull up into the intersection, waiting for my time to turn left when traffic allows, I go a little wide and then turn the wheels as I come to a stop. This allows the rear wheels to go at slightly different speeds, and the noslip opens up under low force, making the resulting turn much smoother when I step on the gas. Since I mastered this technique, which isn’t that hard to do, the noslip is so much easier to drive. I had just gotten used to punching the gas in a turn. Once I got used to not doing that, or at least knowing how it will react when I do punch it, its so much better than before.
I also installed the cheap james duff traction bars. Spring wrap-up on a ranger is quite significant. This solved that problem quickly.
Once I was convinced that the noslip was working properly, and then modified my driving habits, I’ve grown to love the noslip. I wouldn’t go back to an open diff. I’ll put a noslip in every truck I ever own, it’s made that much of a difference. My advice: Take the rear cover off, assure yourself that no damage is being done. Then go out and learn how to drive it. It takes a little getting used to, but once learned makes it awesome on the street.
I hope this helps!
--Bob
. . bad choice. . .no more hot roddin' for him.
