Salisbury or Dana: Which Diff Do I Have?

Most US-delivered Jaguars use the Salisbury differential, but during the 1984-87 timeframe a number of XJ-S vehicles were built with "Dana" diffs (and the Dana diff seemingly was used in other models in Europe).Why is this important? Because the cars equipped with Dana diffs use different rear brake rotors due to the fact that the rear brake calipers mount to the differential in a slightly different way. It is also useful to know which diffs you have when looking to purchase a rebuilt diff, as in general a Dana diff core is not acceptable in exchange for a rebuilt Salisbury differential.

Dana differentials can only be identified by looking at the unit. There are two ways to identify a "Dana" differential: The easiest is that a "Dana" DOES NOT have a drain plug on the bottom of the differential and the bottom of the diff is flat. The other way is that the stub axle bearing retainers (behind the output flanges) are triangular with three mounting bolts. See our pictures of the two types of diffs.

The pictures below will help you determine if you have a "Dana" differential.

Standard Jag Diff	"Dana" Style Diff
Bottom of diff: Note the drain plug and non-flat bottom	Bottom of diff: Note lack of drain plug and the completely flat bottom
Output flange: Note shape of 5-bolt bearing retainer behind flange. Caliper mounting boss is part of the bearing retainer	Output flange: Note 3-bolt triangular bearing retainer behind flange. Caliper mounting boss is part of differential case itself
Pinion flange: Circular	Pinion flange: "Square"