Detroit Locker

Detroit Locker Install

Most factory 4wd trucks are sold with "open" differentials. The differential is a device inside the axles that allows one wheel to turn faster than the other. An "open" differential is good for driving on the street but on the trail because it directs engine power to the wheel with the least traction. Note the picture above, without locking differentials it would difficult to drive forward (up the hill) as the right front and left rear wheel would spin free and the other two wheels would not receive any power at all. Replacing the stock differential with a locking unit solves this problem and keeps all 4 wheels turning together.

Some trucks are available with a Limited Slip Differential (LSD). These units help move power form the wheel that is spinning to the one that is not spinning by means of internal clutches. LDS's are great in street and occasional off road situations but do not provide 100% lock-up that results from using a true locker.

My rear Detroit locker has performed very well over the years and I have been very happy with it, so I choose to purchase another unit for the front axle. Other options for lockers include ARB, Lockright, and Toyota's own electric locker (this will be featured in an upcoming article). When choosing a locker for your truck take time to talk to others about the advantages and disadvantages of lockers they are using.

When my front Detroit locker was installed I snapped a few pictures and took notes on how the locker was installed. I already had the 4:88 V6 gears put in several weeks previously so what follows is only the information on the locker installation on a 8" Toyota differential. The specifications below are for 1987-1995 Toyota V6 8" differentials.

	After removing the axles shafts from the tubes and unbolting the drive shaft the 3rd member unbolts and comes out easily. Left picture is of the new Detroit locker itself. The Detroit installs in place of the stock spider gears and carrier.
	Use a bearing puller to remove side bearings. Remove adjusters locks, end cap bolts, carrier and ring gear bolts.
	A little tap with a brass hammer will help remove a stubborn ring gear. Once removed the ring gear can be mounted onto the Detroit locker. Red Lockright is used here to prevent the bolts from vibrating loose.
	Torque ring bolts to 71 ft/lb. An optional step that can be done to limit the side bearings from spinning on the locker is using a little red Locktight on the race. Be careful not to get Locktight in the bearings.
	Use a hammer and driver to tap bearings onto locker.
	Using a stone to resurface housing (to prevent oil leaks). Be sure to clean out the inside of the housing before putting the ring gear assemble back in. You want to get all those little metal bits out.
	Rotate the side gears to to adjust backlash. Check backlash with a dial indicator. Should be set to .0051-.0071 in. play.
	Torque end caps down to 58 ft/lbs. Test frictional drag with a torque meter It should be 10-15 in/lbs with used bearing or 16.5-20.6 in/lbs with new ones.
	Adjuster lock bolts need to be reinstalled and torqued to 9 ft/lbs. Reinstall the differential the same way it came out. You can use silicon gasket goope or a factory housing gasket to seal the 3rd member in the axle.