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Trac-Loc Assembly Made Easy

Although Powr-Loks may be the limited slip of choice for many applications, they are not available for every application and they are priced much higher than their Trac-Lok counterparts. Over the years, Trac-Loks have gotten a bad rap for several reasons. The original Trac-Loks had very weak spider gears and a weak case that would break in half under a heavy load, not what anyone wants from a locker. I would not be surprised if many readers have seen at least one broken Trac-Lok or have broken one of the older locker designs themselves.

Dana Spicer has become one of the world's leading manufacturers of differentials and differential parts by constantly making improvements. Being aware of the shortcomings of the Trac-Lok locker, and the high cost and low OEM demand of the Powr-Lok locker, Dana has made several improvements to the Trac-Lok design over the past ten years. The cases have been beefed up and are now much meatier and made of stronger metal. The spider gears are now produced from a much stronger steel than was used for earlier models and the cross pin shaft retention has been improved on models where improvement was needed.

The results of these changes have made a much better unit: a limited slip that holds up well when abused by horsepower and tall tires as well as lasting fairly well in many applications. Even if it is not the best for a rear differential, it does work well in many front differentials.

Tthe Trac-Lok clutches were never very aggressive and they never lasted as long as the Powr-Loks, but then again they are a lot cheaper and it is still less expensive to replace the clutches once or twice in a Trac-Lok than it is to spring for the Powr-Lok. And, if the Powr-Lok is not available for a particular application for which the Trac-Lok is, any point about clutches doesn't matter. If you need more traction then step up and spend the extra money for a locker.

Now that I have done my best to defend the underdog, I'll share a few tips that make it easier to assemble a Trac-Lok. In order to make assembly easier I use two homemade "tools" (along with the units own cross pin shaft) that make a world of difference. The first is a common bolt and nut. A 1" x 5" coarse thread bolt and nut with a few washers will work well for many different size Trac-Loks. The second "tool" involves three pieces, a large C-clamp and two spider pinion gears that are of equal or lesser size than the ones in the locker being assembled.

The bolt is used to compress the clutch pack on one side of the locker while the case is being spun into place around the internals by pulling on the cross pin shaft with a pipe for increased leverage. Be careful how much force is being used and watch the position of the shaft, so the case is not damaged.

The C-clamp and extra spider pinion gears are used to compress the clutches on both sides of the locker at once so the thrust washers can be installed without pressure on the locker's own spider pinion gears.

This technique may seem awkward at first, but with practice it makes assembling just about any Dana Spicer Trac-Lok pretty easy, or at least without large hammers and a lot of swearing.

Check out the Dana Spicer Trac-Loks, and other Traction Lockers, we have available for sale. If you're not interested in a Dana Spicer then take a look at the lockers from Yukon DuraGrip, Spartan Locker, or Detroit. Also, don't be fooled by the terminology, a Trac-Loc is the same as a Trac-Lok.

- Randy Lyman

The content of this page has been provided courtesy of Randy’s Ring & Pinion