Here’s a scenario for you. Imagine that you’re sitting at the red light in front of your local cruiser hang out, and the guys standing around on the corner are giving you a hard time about doing a burnout. You think it would be cool to do it, but you’re faced with a dilemma. You know that your car has an open rear end, and doing a one wheel burnout will be almost as embarrassing as not doing a burnout at all. In an effort to help you stave off embarrassment, you need a limited slip differential of some kind.
The limited slip differential (LSD) is a great upgrade to your car, and Eaton has been building them for years. Unlike a clutch-based differential, the Truetrac is designed around a six pack of helical-cut gears. This gear system eliminates the need for any clutches in the differential. Since no clutches are used, this means that no oil additives (hypoids), are required. Just add the appropriate rear end oil, and go.
But, one thing to keep in mind is that not all oils are recommended for use with the Truetrac. Eaton recommends using mineral (non-synthetic) gear oil to obtain nominal operation. They tell us that some synthetics cause noise, and might even lower the biasing capabilities.
Finally, if you are worried about this type of differential making a lot of noise, put that thought out of your head. The Truetrac does not operate the same way that a locker does. In fact, the design and implementation of the gear system assures that the Truetrac’s operation is smooth and quiet. This means that you won’t even realize that it’s the car until you actually need it, and the extra traction makes an appearance. The unit will engage/disengage without any indication that it ever happened. What’s more, is that since it has no clutches or wearable parts, it requires virtually no maintenance other than an occasional oil change.