My center locking differential actuator recently cooked itself and I decided to give rebuilding it a go. My windings were completely shot and I didn't find anyone else on here rewinding the motor, so I thought I’d write up my experience to hopefully help someone in the future. Please feel free to correct anything I did wrong as this was my first time doing this type of repair.
The windings are 26awg. I used Amazon ASIN: B08N1FCMV9. I got the 8 oz version, but it is not available at the time I'm writing this. 8oz is plenty to screw up numerous times. The wire I ordered had a dual layer insulation of Polyesterimide base coat + Polyamideimide top coat.
If you choose to change the rotor bearing it is a NSK 608Z
1. First remove the actuator
3. Remove rotor, careful to not catch the brushes
4. Tap a razor under each of the fingers holding the windings to pry them open slightly.
5. Remove all the windings
6. Mark the lobes 1-5 as shown below, so you know the order that you are to wind it. (it doesn’t matter where you start it just has to be in this pattern)
7. Use a razor to scrape the insulation off the end of the wire (make sure you get all the way around, so it makes good contact)
8. You will start at the left finger on lobe 5, wrap the stripped wire around this finger. Next cross over to lobe 1. With lobe 1 facing up you wrap around the finger on the right side. You again have to use a razor to strip the wire where it contacts with the finger. (you can check your work by testing continuity from the copper pad to the copper pad of the previous finger)
9. Now wrap the wire 61 times clockwise around the lobe. Careful to not lose count and keep the windings tight and neat else it may interfere when doing the lobe next to it.
10. After the 61 wraps bring it around the left side finger and again strip where it makes contact.
11. Cross over to the right finger of lobe 2 and repeat steps 8-11
12. Repeat until fully wrapped. You will end on the same finger you started at.
13. You have to crimp down all of the fingers, but I would assemble and bench test the motor prior to doing this so you don't stress the copper if you have to redo something.
This is what the winding will look like. Wrap the end of the wire around finger 1 then cross over and around finger 2. Wrap 61 times clockwise around the lobe, then around finger 3. Cross over to finger 4 and so on until you end back where you started at finger 1/11. Its good to do a test run of this by only doing a few windings around each lobe just to make sure you understand how it needs to be wrapped before spending the time to wrap it 60 times.
15. Check your continuity between adjacent pads to ensure you didn’t forget to strip something (like I annoyingly did on my first attempt)
16. Check your bearing as mine was pretty stiff from the heat. To press it out remove the jamnut and screw from the opposite side and find a metal rod that barely fits the bore. Remove the three screws from the board that the brushes are mounted on. I placed the surface that the motor housing bolts to on two pieces of wood so that the board was elevated and used a press to press the bearing out. Press the new one in. Be careful not to damage the board as it can be pretty brittle especially if it was heated as much as mine was. (I ended up cracking it later on and epoxied it back together)
17. I took the C clip off the gear shaft and cleaned and re-greased everything. (I used a high performance ptfe filled grease because it is easy for me to get and felt it should work well, others may have a better suggestion)
18. Put the gear so the stop is somewhere in the center and put the motor back together. You’ll have to make sure to hold the brushes all the way in to slide the rotor by them. If you removed the screw/jamnut to replace the bearing make sure not to bottom out the screw onto the rotor. It should be slightly loose else the rotor wont spin.
19. Use a 9-volt battery to test the motor. Leave the cover off of the gear so you can see it turn. The connector has a row of three pins and a row of 2 pins. Apply 9V to row with 2 pins and the motor should spin. Reverse the polarity and it will reverse the direction. Make sure you don’t bottom out the motor on the stop.
20. Connect the motor to the car and turn on the lockers. If you can have someone look to see if the motor spins in case something else is broken as well. Mine didn’t work at first, I’m not sure if this was the connector or if the housing had to contact something metal for ground, but I cleaned the contacts and placed it on a box leaning against the transfer case and it worked.
21. You have to install it with both the motor and transfer case locked (according to another thread on here), so disconnect the actuator when it is in the locked position. To lock the transfer case lift one wheel off the ground and spin the gear in the transfer case counterclockwise while spinning the lifted wheel (I used my foot to spin the wheel while moving the gear). You’ll be able to feel it engage.
22. Reinstall the motor and put everything back together and go test it on some gravel.
23. Note if your motor burned up it may be the effect of another issue like a relay issue. Check the rest of your system. This is a pretty good writeup on troubleshooting the system. Troubleshooting the Toyota FJ80 Land Cruiser Center Diff Lock (CDL) - https://www.pnwadventures.com/toyota-fj80-landcruiser-cdl-troubleshooting/
I may still be having issues with my system as the relay chatters rapidly while the motor is spinning. I also hear a relay chattering while driving. This may be a different relay, but it is difficult to know because it only happens while I’m moving and isn’t consistent. If this is potentially activating my motor when it is at a dead stop it may be what burned it up. For now, I pulled the fuse when I don’t need the lockers and will have to investigate further.
The windings are 26awg. I used Amazon ASIN: B08N1FCMV9. I got the 8 oz version, but it is not available at the time I'm writing this. 8oz is plenty to screw up numerous times. The wire I ordered had a dual layer insulation of Polyesterimide base coat + Polyamideimide top coat.
If you choose to change the rotor bearing it is a NSK 608Z
1. First remove the actuator
- support the transfer case with a jack
- remove 8 bolts on the support member
- lower jack a few inches (don’t need much extra space)
- Undo electrical connector
- Remove 4 bolts connecting actuator to transfer case.
- Pry the actuator off (this was a pain as there aren’t many places to pry from)
3. Remove rotor, careful to not catch the brushes
4. Tap a razor under each of the fingers holding the windings to pry them open slightly.
5. Remove all the windings
6. Mark the lobes 1-5 as shown below, so you know the order that you are to wind it. (it doesn’t matter where you start it just has to be in this pattern)
7. Use a razor to scrape the insulation off the end of the wire (make sure you get all the way around, so it makes good contact)
8. You will start at the left finger on lobe 5, wrap the stripped wire around this finger. Next cross over to lobe 1. With lobe 1 facing up you wrap around the finger on the right side. You again have to use a razor to strip the wire where it contacts with the finger. (you can check your work by testing continuity from the copper pad to the copper pad of the previous finger)
9. Now wrap the wire 61 times clockwise around the lobe. Careful to not lose count and keep the windings tight and neat else it may interfere when doing the lobe next to it.
10. After the 61 wraps bring it around the left side finger and again strip where it makes contact.
11. Cross over to the right finger of lobe 2 and repeat steps 8-11
12. Repeat until fully wrapped. You will end on the same finger you started at.
13. You have to crimp down all of the fingers, but I would assemble and bench test the motor prior to doing this so you don't stress the copper if you have to redo something.
This is what the winding will look like. Wrap the end of the wire around finger 1 then cross over and around finger 2. Wrap 61 times clockwise around the lobe, then around finger 3. Cross over to finger 4 and so on until you end back where you started at finger 1/11. Its good to do a test run of this by only doing a few windings around each lobe just to make sure you understand how it needs to be wrapped before spending the time to wrap it 60 times.
15. Check your continuity between adjacent pads to ensure you didn’t forget to strip something (like I annoyingly did on my first attempt)
16. Check your bearing as mine was pretty stiff from the heat. To press it out remove the jamnut and screw from the opposite side and find a metal rod that barely fits the bore. Remove the three screws from the board that the brushes are mounted on. I placed the surface that the motor housing bolts to on two pieces of wood so that the board was elevated and used a press to press the bearing out. Press the new one in. Be careful not to damage the board as it can be pretty brittle especially if it was heated as much as mine was. (I ended up cracking it later on and epoxied it back together)
17. I took the C clip off the gear shaft and cleaned and re-greased everything. (I used a high performance ptfe filled grease because it is easy for me to get and felt it should work well, others may have a better suggestion)
18. Put the gear so the stop is somewhere in the center and put the motor back together. You’ll have to make sure to hold the brushes all the way in to slide the rotor by them. If you removed the screw/jamnut to replace the bearing make sure not to bottom out the screw onto the rotor. It should be slightly loose else the rotor wont spin.
19. Use a 9-volt battery to test the motor. Leave the cover off of the gear so you can see it turn. The connector has a row of three pins and a row of 2 pins. Apply 9V to row with 2 pins and the motor should spin. Reverse the polarity and it will reverse the direction. Make sure you don’t bottom out the motor on the stop.
20. Connect the motor to the car and turn on the lockers. If you can have someone look to see if the motor spins in case something else is broken as well. Mine didn’t work at first, I’m not sure if this was the connector or if the housing had to contact something metal for ground, but I cleaned the contacts and placed it on a box leaning against the transfer case and it worked.
21. You have to install it with both the motor and transfer case locked (according to another thread on here), so disconnect the actuator when it is in the locked position. To lock the transfer case lift one wheel off the ground and spin the gear in the transfer case counterclockwise while spinning the lifted wheel (I used my foot to spin the wheel while moving the gear). You’ll be able to feel it engage.
22. Reinstall the motor and put everything back together and go test it on some gravel.
23. Note if your motor burned up it may be the effect of another issue like a relay issue. Check the rest of your system. This is a pretty good writeup on troubleshooting the system. Troubleshooting the Toyota FJ80 Land Cruiser Center Diff Lock (CDL) - https://www.pnwadventures.com/toyota-fj80-landcruiser-cdl-troubleshooting/
I may still be having issues with my system as the relay chatters rapidly while the motor is spinning. I also hear a relay chattering while driving. This may be a different relay, but it is difficult to know because it only happens while I’m moving and isn’t consistent. If this is potentially activating my motor when it is at a dead stop it may be what burned it up. For now, I pulled the fuse when I don’t need the lockers and will have to investigate further.