If you have purchased a complete 3rd member with a locker in it, or have purchased a locker that you wish to have installed in your existing differential housing this article will describe how to pull apart a Discovery Series II rear axle, remove the 3rd member, and put everything back together again. The procedure is also documented in the Land Rover Workshop Manual.
Thanks to Dan Cronin who walked me (and several others) through all of this a few years back.
Supplies
- Floor Jack
- Jack Stands
- Wheel Chocks
- Bungee Chords
- Very large phillips screwdriver
- Lugnut wrench
- Socket Set
- Rubber mallet
- Steel mallet
- Razor blade
- Gear oil
- Bearings:
Available from Applied Industrial Technologies in Everett- 2 Timken roller bearing race - part number LM102949
- 2 Timken tapered bearing race - part number LM102910
- O-rings for DII axles. Available from Land Rover Parts. Part Number FTC4919
- Black Permatex High-temp RTV
- Latex Gloves
- ARB RD128 Air Locker
Disassembly
Step 1: Remove Harmonic Balancer
Using a 1/2" socket, remove the two bolts that secure the harmonic balancer to the differential housing.
Tie it up on top of the axle to get it up and out of the way, or remove the tether with a large crescent wrench and set the entire thing to the side.
Step 2: Disconnect the rear driveshaft
Using a 9/16" socket and a 9/16" spanner remove the bolts that secure the driveshaft to the rear differential output flange. Note that these wrench sizes are for my driveshaft which has been converted from the rotoflex to a standard Land Rover driveshaft.
Once the driveshaft is disconnected, tie it up and out of the way so you have free access to the rear axle.
Step 3: Drain the fluids out of the rear axle
Place an oil drain pan under your rear differential housing.
Use a 1/2" socket driver w/o a socket to loosen the drain plug, and remove it. Letting the oil flow into the oil drain pan.
The drain plug is magnetic and will have metal shavings attached to it. Inspect the drain plug for excessive metal shavings. A few are normal, if it looks like a troll then something is wrong with your differential, or ring/pinion.
Replace the drain plug, finger tight. We'll come back to it later when we clean out the axle, so there is no need to tighten it down firmly at this time.
Step 4: Loosen lugnuts on both rear wheels
Step 5: Jack truck up and put it on jack stands.
Chock your wheels very well. Double check that the vehicle is in Park, and that the emergency brake is securely fastened. WARNING!!! You are going to be underneat a 5000lb vehicle. Failure to properly chock your wheels, and secure your vehicle on jack-stands, is likely to cause serious injury or death. DO NOT WORK UNDER YOUR VEHICLE WHILE ONLY SECURED BY A JACK. JACKSTANDS ARE MANDATORY.
Step 6: Remove both rear wheels
After removing the wheel, I like to place it under the slider to hopefully catch the truck if it falls off the jack-stands.
Step 7: Unbolt rear calipers and bungee cord them up.
Using a 1/2" or 13mm socket, loosen the two bolts that secure the rear brake caliper.
Use a bungee chord or other strapping device to tie them up and out of the way. DO NOT let the caliper dangle by the brakeline.
Step 8: Remove brake rotors (Need large phillips screwdriver and maybe a rubber mallet)
Use a large phillips screwdriver to remove the rotor screw. Many people discard these, but I'm not a professional mechanic, so don't take my word for it.
Use a rubber mallet to work the rotor off of the hub. You'll need to keep hitting the back of the rotor at 3:00, 9:00, 6:00, 12:00, etc rinse and repeat until the rotor comes off.
Step 9: Unbolt rear hub.
Using a 15mm socket, loosen and remove the four bolts that secure the hub to the axle housing.
Step 10: Disconnect ABS sensor
Disconnect the ABS sensor, and slide the entire wire through the hole in the axle. This is in preparation of removing the entire axle/hub.
Step 11: Slide hubs/axles partially out to free the diff. Watch out for oil draining out of axle
Place an oil drain pan under the hub.
If necessary, use a mallet to get the hub to separate from the axle housing.
Step 11: Unbolt the 3rd member and pull it out.
Using a 9/16" socket, remove the bolts that secure the differential housing to the rear axle.
Place a dolly, or other maneuverable platform under the axle and separate the 3rd member from the axle gently placing it on the dolly.
Step 12: Install the ARB locker into the diff carrier per ARBs instructions
If you have purchased a completely assembled 3rd member from GBR or another Land Rover driveline supply shop, you can skip this step and proceed to re-assembly.
If you need to have your locker installed for you, there are a variety of shops in the PNW that setup Land Rover 3rds.
Wild Kingdom Offroad - Dan Cronin, in Bothell, WA does an excellent job. He did mine.
Lamorna Garage - Gordon Perrot is in Seattle, WA (Ballard)
Ship's Mechanical Services - Doug Shipman in Portland, OR
Reassemble
Step 1: Clean axle and differential housing mounting faces of all RTV, old oil, etc.
Use a razor blade to scrape old RTV off the differential housing or the axle housing mating faces.
Use a rag and some brake cleaner to remove old oil
I also wire brushed the bolts that secure the differential to the axle housing
Step 2: Remove any gunk from the inside of the axle housing
Place the oil drain pan under the axle housing
Remove the drain plug
Using your fingers, rag, etc push any old oil, RTV chunks, metal flakes, etc out of the axle housing.
Replace the drain plug, this time tightening it securely with a 1/2" Socket Driver.
If necessary, re-spray the axle housing face with brake cleaner to remove any oil residue.
Step 3: Apply a bead of RTV to the axle housing differential mating face. Make sure it is solid, but don't overdue it.
Step 4: Insert the 3rd member into the axle housing and secure.
The 3rd member is the differential housing with differential, and other components installed.
When inserting the 3rd member into the housing, be very careful to not pinch the copper airline tube (ARB air locker)
Use a drop or two of Loctite 243 on each of the bolts that secure the 3rd member to the axle housing.
Torque each bolt to 55Nm
Step 5: Re-attach the harmonic balancer
Step 6: Replace the O-rings on each of the axle halfshafts
Remove the existing O-ring
Use a soft wire brush and a clean rag to clean out any rust, dirt, sand, metal shavings, or other debris and jagged edges from the O-ring channel in the axle. Debris and sharp edges can cause pre-mature wear on an O-ring, so you want to make sure it's really clean in there.
With a set of clean latex gloves on, lightly coat the O-ring with a layer of oil. This will help it to seal up right away.
Slip the O-ring over the end of the axle and into the O-ring groove.
Step 7: Fit axles into axle housing
Align the hub bolt holes, and the halfshaft axle teeth with the teeth of the differential and insert them into the axle.
Tighten the hub bolts to 100Nm
See the disassembly section for photos that include the location of the hub bolts.
Step 8: Re-attach ABS sensors
Route the ABS sensor through the hole in the axle and plug the two ABS sensor sections together.
If you have extended ABS sensor lines, be sure and zip tie them at this point too, so they don't get caught up in anything.
Step 9: Install rotors over the hubs
Place the rotors over the top of the hubs, and seat with a rubber mallet as necessary. Working around the edges in a star pattern seems to work the best.
Step 10: Re-install calipers
Unhook the calipers from their bungee restraint, and place them over the rotor.
Torque the brake caliper bolts to 95Nm
If for some reason you find that you need to open the calipers up (e.g. if they are distended) and you need to re-torque the guide pins, the guide pins torque to 30Nm. In general, you should not need this information.
Step 11: Reinstall wheels
Torque wheel lug nuts to 140Nm
Step 12: Fill the axle with gear oil
Loosen the filler plug in the middle/rear of the axle housing
Fill the axle until it begins to overflow
Reinstall the filler plug
