FAQ

1. Bolt pattern on the housing flange. Center hole to center hole, vertically, and horizontally. The diameter of the hole. This determines what flange you have.
2. With the axle in the differential, measure from the face of the housing flange, to the outer face (drum/rotor mounting surface) of the axle. This determines the axle off set (or backspace).
3. The outer diameter of the circle in the center of the axle flange, where the drum/rotor centers on the axle. This determines the register size.
4. The outer diameter of the axle bearing. This determines if you have big bearing, or small bearing.

Ford small bearing diameter = 2.835

Ford big bearing diameter = 3.1515

Fastener torque spec: 45 foot pounds for all fasteners

3 1/2 – 4 quarts of any reputable 80/ 90 weight gear lube.

Clutch style posi (trac lock), must use non-synthetic gear lube only, and an additive ( ford p/n:xl-3 – motor craft additive, friction modifier. Additive provided with all John’s Trac-Loc units).

Truetrac, and open carriers, can use synthetic or non-synthetic gear lube.

P/n: PM51098 – ford 9″ big bearing axle seal (also National p/n: 473228)

Install seal by using an implement that will push the seal evenly as it goes in. The open side of the seal, with the coil spring, goes toward the third member. If the seal is installed correctly, it will measure 1 3/8″, from the top of the seal to the end of the housing flange. Dip seals in gear lube, prior to install.

Contents of provided hardware kit:

• 8 – 3/8″ t-bolts with ny-lock nuts
• 10 – ny-lock nuts for third member studs (installed in housing)
• 1 – steel spring loaded vent – 1/8″- 27- npt (tapped hole provided on driver side of axle housing)
• 10 – copper crush washers
• 2 – axle seals p/n:pm 51098
• 3 – weld on fold over brake line tabs
• 1 – third member gasket

Pinion off set when housing is centered is 1 1/4″ to the passenger side.

All wheel cylinders take 3/16″ standard line.

John’s builds rear axles, wheel mount to wheel mount, to insure the same track width as a stock rear axle. We allow 1/4″ overall for drum brake use, and 1/2″ overall for disc brake use.

Ford 9 inch gasket p/n: P27929

Lokar part numbers for emergency brake cable kit

P/n: EC81-FU for use with disc

P/n: EC80- FU for use with drum

The Truetrac is manufactured by Eaton. It is a gear to gear posi that drives on the street like a standard limited slip. It requires no additive, and synthetic oil may be used. This carrier is rated to 750hp.

The Trac-Loc unit is a clutch style posi; it requires an additive.

Ford motor company p/n: XL-3, which is provided with every TracLoc John’s ships out. This unit can only use non-synthetic oil, as synthetic oil will render the clutches useless. This unit is great for most street applications, and is rated to 450hp.