Living With Limited Slip Differentials

When you pull the carrier, it's vital to keep the shims separated so you know which side they were on originally. Sometimes, depending on which type of axle you have, you can reuse the original shim packs, and sometimes not. No matter what, mark the original shims so you know the dimensions. In this case, we replaced the original one-piece shims with Randy's Ring & Pinion Super Shims. The kit comes with two hardened faces between which you stack smaller shims to make up the exact total thickness you need. That eliminates the need for lots of shims in stock.

When you pull the carrier, it's vital to keep the shims separated so you know which side t

With wide differences in tire grip, side to side, and a heavy load, the LSD may be overcome and the low-traction tire will still spin. You can augment the braking power of the LSD clutches by applying the parking brake (if it operates on the rear wheels), or by brake pedal modulation (a gentle on/off of the brake pedal). The parking-brake trick is preferable because it does not increase rolling resistance by also braking the front tires.

If a bias ratio of 3.5:1 isn't enough (especially in a light rig), consider a locker. In most cases, an automatic locker is much more livable on the street than a very high bias-ratio LSD.

With any given bias ratio, a light vehicle will be more affected in the drivability department than a heavy one-and vice versa. On the other hand, the higher bias on the light vehicle will deliver better traction in the dirt than it will on the heavy one.

Low-bias LSDs are best for front axle use so as not to impede steering in tight quarters.

The LSD is a good choice for terrain where the difference in traction side to side is typically not huge-mud, snow, sand, etc. Very uneven rock with tire lifting is the worst venue for it (though it can be augmented via the techniques listed above). To improve lifted tire performance significantly requires a high-bias unit or a locker.