Product Review: Limited SlipApril 16th, 2010 by admin
What’s the best limited slip out there? I am asked that question everyday and I generally respond with another question: what do you use the vehicle for? Usually we say our trucks are on and off road, half and half, and need our daily drivers locked up front and rear. In reality, that is wishful thinking. We wish we were off-road half the time but most of our miles are from running errands and going to work.
This doesn’t mean we don’t need traction. Regardless of brand, the factory limited slips just don’t cut it. Even with a lift kit and bigger tires, half the trucks out there still get stuck in wet grass. There are several options depending on your particular vehicle:
1. An upgraded limited slip, such as the Auburn and Eaton, utilizes stronger springs and higher friction clutch plates. These are like the factory units on steroids, and they work great. They are also usually less expensive than the factory units, making them an ideal choice whether replacing a broken unit or upgrading your stock open differential.
2. There is another limited slip that is my personal favorite: the Detroit Tru-Trac. This is a helix gear driven limited slip and doesn’t have any clutches or springs. It also works in conjunction with the traction and torque demands, whereas a clutch unit works the opposite. Think of it like a stick shift clutch on a car. If you’re easy on it and don’t demand much, it works fine. If you start working it hard and heating it up, it fades. So the more you need/abuse it, the less it works. This is also true of a clutch limited slip. The harder you push it, the more it slips, and consequently the less it works. The Tru-Trac is a torque-driven unit, meaning the harder you push it, the tighter it gets, and the better it works. This also means that when you’re casually driving on the street and make a sharp turn, it won’t hop and chirp like a tight clutch unit. Being solid metal, there are no wearing parts and no additives or friction modifiers needed. Sometimes the simple design really is best.