Lock-Right Installation for Toyota 8" Carriers

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Author: Luke Miller Editor: Scott Wilson April 2000

Coating the teeth of one of the drivers

1. Put grease on the mating surfaces of the locker parts. Coat the teeth of the couplers (these are going where the side gears used to be) and the drivers (these will reside in the center and contact the couplers on their outer face and the pinion shaft on their inner surface). Place a bit of grease in the window holes in the drivers where the pins will be installed.

The pin is set in one of the two holes with the larger window opening

2. On each of the two drivers, install a pin into two of the holes. Use the two holes that have a larger opening on the side of the driver. When you assemble the locker, you will be sliding these pins across into the opposite driver, so when things are set up properly, each pin will reside in its own hole.

The thrust washer is placed on the back side of the coupler

3. Place the spacer rings into each driver. Your spacer rings will be symmetric, so you can ignore the instruction's warnings about wide and narrow ends on the rings. Place a thrust washer on the back side of each coupler, similar to how they sat on the original side gears.

The two couplers in place in the carrier

4. Starting on the ring gear side, install the coupler (with its thrust washer in place). The coupler has flats on it to allow you to slide it into the carrier. Then place the other side's coupler in place.

One driver is in place, notice the pin we placed in the large window hole earlier Both drivers in place in the carrier

5. Now you will place the drivers in place. Again the instructions make a comment about making sure your spacers are properly oriented, but our Toyota spacers are symmetric, so we don't have to worry. Just slide the driver in place and mesh the teeth with the coupler on that side. The grease you placed on the teeth should be sufficient to hold it in place. Now put the other driver in on the other side, again pressing it into the grease on the coupler to hold it in place.

Sliding the pin through the hole to engage the other driver

6. The pins you installed in the drivers now need to be slid across to the other drivers to lock them together. Line up one hole with a pin with an empty hole on the other driver. Then slide the pin across to the other driver. Repeat this for the other three pins, rotating the driver assembly as needed to get access.

Placing a small spring within a larger spring Inserting the springs into one of the large window holes

7. Those springs have been staring at you for a while, now is the time to use them. Slide a small spring inside a big spring, and place it in one of the large window openings where you were just playing with the shear pins. You will compress the spring and slide it into place behind the pin in the hole. Use a small screwdriver or something similar to make sure the spring is fully seated down in the hole. Repeat this for each of the other three sets of springs at each of the other holes.

Inserting the pinion shaft back into the carrier

8. The pinion shaft will be installed next. The drivers need to be rotated so their central hole will allow the pinion shaft to slide through them. When putting the pinion shaft in, be careful to orient the retaining pin hole properly so you can drive the retaining pin back through the pinion shaft.

9. Pound the retaining pin back through the pinion shaft to anchor the shaft in place. To keep the retaining pin in place, slightly deform the ends of the hole in the carrier where it resides to stop it from sliding out.

10. You are now ready to reinstall the ring gear. Getting the ring gear back on may be less fun than getting it off was. The ring gear needs to be warmed to make it expand enough to fit back on the carrier. The Toyota factory manual recommends heating it in an oil bath to around 200 degrees Fahrenheit. But it specifically states that you must not exceed 212 degrees Fahrenheit to avoid ruining the heat treatment the ring gear was given when it was made. Other people have use judicious heating with a torch as a substitute, or simply heating the ring gear in an oven. My method was to simply leave the ring gear sitting in the sun while I had been doing the rest of the install. On a hot day in Southern California, this was sufficient to expand the ring gear enough to get it back on the carrier. The ring gear will not just slide onto the carrier, it will need to be tapped (or pounded) back on. Be sure to get the ring gear properly lined up with the carrier.

11. Make sure the back side of the ring gear and the face of the carrier are clean and dry to avoid trapping anything between the ring gear and carrier that will affect the torque of the ring gear. Once the ring gear is in place, install the ring gear bolts and locking tabs. The factory manual suggests lubing the bolts with gear oil and torqueing them to 71 lb-ft (1985 Toyota factory manual spec, check your application). Bend the locking tabs into place.

12. Your Lock-Right is now installed in the carrier, and now you need to reinstall the carrier in the 3rd member housing. This is probably best done with the housing sitting vertically in a coffee can.

13. You were careful to mark the carrier bearing races when you removed them, so now you can replace them on their proper sides on the bearings. Then the carrier can be set into the housing.

The carrier in place, with the carrier bearing races in place

14. With the carrier in place, you will push it as far as it will go towards the side opposite the ring gear (making sure the bearing races are fully on their bearings). This acts to force the ring gear against the pinion, eliminating any backlash. Try it, when done properly you should feel no play between the ring gear and pinion, instead of the amount of backlash you felt before you disassembled the gears.

15. Find the adjuster ring for the ring gear side, and orient it with its mark in its final position (probably straight up). Place the adjuster ring against the bearing race and slide it down into the threads. There should be no space between the adjuster and the bearing race.

The adjuster ring (arrow) in place, flush against the bearing race behind it

16. Now get the carrier bearing cap for the ring gear side and orient it properly. It should slide down on the adjuster ring. Use the two bolts to line it up so everything goes together smoothly. Snug up the bolts.

The other adjuster in place, marks oriented straight up as they were when we disassembled the diff

17. The other adjuster ring is ready to be installed now. Orient it with its mark in the final position. Start it out flush with the bearing race, and slide it down into the threads. As you do this the meshing of the threads will force the adjuster ring outwards away from bearing race. Get the other carrier bearing cap, orient it properly so its punch marks match the marks you put on the housing, and use the bolts to help position it over the bearing race and adjuster. Slide the cap down, and it should mesh nicely. Snug the cap bolts.

Using a brass punch to drive the ring gear adjuster around one full turn

18. Now you will set the bearing preload and backlash. The adjuster ring on the side opposite the ring gear is sitting out away from the bearing race just a bit. You will use a punch to rotate the adjuster ring clockwise, threading it in towards the bearing race. The first half of the turn should go easily, until the adjuster ring starts to contact the bearing race. The last half will require some force to turn the ring, as you are creating the preload and moving the ring gear away from the pinion gear to create the backlash. The adjuster ring should end up with the mark in the same position as when you marked it and took it apart.

19. Torque the carrier bearing cap bolts 58 lb-ft (as per the 1985 Toyota factory manual, check your manual to insure this is the proper torque for your year). Then install the adjuster locks and bolts, these use very little torque (9 lb-ft).

20. The space in the center between the driver halves should be within .145 to .170 inches. Check to see that you managed to get everything back in its proper place, all the marks line up etc. Check the backlash at the ring gear, rock it back and forth. It should be the same as when you took the gears apart. If the backlash is out of whack, it needs to be reset with a dial indicator, which is beyond the scope of this article. Mine was deemed "close enough" and reinstalled in the axle housing.

21. Use a new gasket for the third member and some gasket sealer to hold it in place and seal the mating from oil leaks. Place the 3rd member in the axle housing and install the ten bolts around the outside of the 3rd member and torque to spec. You should then be able to slide the axle shafts back into the differential and put the axle back together.

22. With everything back together, add gear oil and test the locker. Rotating the tires with the axle up on jack stands and the transmission in neutral, the locker should ratchet freely as you rotate one wheel. This is the sound of the locker disengaging, you will hear this sound when coasting around tight turns in the parking lot with the window down and radio off. With the transmission in gear, the locker should lock up when you try to rotate the tires.


The locker will drive differently than your open differential. To mask the locker when driving, you will learn to be more careful with your application of throttle. The locker makes itself know when making U-turns and 90 degree turns at intersections. In these cases, it helps to either coast with the clutch in or to drive with steady throttle through the turn. In more gentle turns and on the highway, the locker will be less noticeable as it engages and disengages. In the rain and snow the locker can cause other handling quirks, and you should be careful when first driving the locker in these conditions.

Off road and in the snow, the locker will lock both wheels together and can make for fun on sidehills. Since both tires are locked, when they spin, both wheels spin and you have lost grip with the ground, so the axle will start to move with gravity downhill. With the open differential, only one tire would spin, and the other would act as an anchor keeping you in place.

Perhaps the best side-effect of the locker is the rare bang that it will make when pressure builds up and the locker released. This will usually happen when starting from a stop, and you will swear something has just blown up under your truck. This is a rare occurrence, but it gets great reactions from pedestrians and other drivers. These handling quirks aside, the difference the locker and the previous open diff off-highway will be night and day, and suddenly you'll be drawn to the harder obstacles, and find yourself spiraling into the endless cycle of harder trails and more money on more parts to tackle those trails.

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