I am trying to attach pictures. I hope this works.
Anyway, I have been having problems with my front locker getting stuck in the locked position for quite some time. In my opinion, it is worse if it gets stuck locked then if it doesn't engage at all.
Anyway, my first call was to CDan, who told me that Toyota does NOT sell parts for the locker mechanism. If it breaks, you have to buy the entire thing – which retails for about $600! Well I figured for that price I had to at least try and fix my old one. So I decided to pull the locker mechanism and see how it worked and why mine might not be working. It is not that hard to take off. Pull 1 plug and remove 4 bolts.
My obversations:
First, this mechanism is built very similar to a windshield wiper assembly. It also sees VERY limited use and therefore does not "wear out" like other parts that are moving all the time. Other than it being encased in an aluminum housing (which is softer than steel), it is very sturdy and I don't see how it could break easily. If you have problems with your lockers I am willing to bet that it either needs to be cleaned or the electrical contacts need to be tightened a little (I'll explain later), but I see NO REASON why the entire mechanism should be replaced.
How it works:
When you engage the locker, a motor winds up a torsion spring that exerts a force on a steel pin that locks (or unlocks) the axle. It is normal for this pin to bind up in the axle itself – that’s why the springs are used. The springs keep a constant pressure on the pin until you turn the steering wheel from side to side. This unbinds the axle and frees up the pressure on the pin and the torsion spring then pulls (or pushes) the pin into the proper position (either locked or unlocked). Turning the locker switch on or off spins the motor forward or reverse and winds the torsion springs in different directions so the pin is either pulled or pushed into the proper position. You can see the torsion springs in the picture.
What could go wrong:
Well in theory, ANYTHING could go wrong, but in practical terms, it is usually something simple – and after disassembling it I would say probably one of 2 things. Either the pin is not sliding freely or, in my case, the copper contacts in the locker mechanism aren't making good contact.
Once you pull off the locker mechanism, you will see the pin that engages the locker. You can push it and pull it with a screwdriver. The bottom of the pin will have teeth on them that make contact with the locker mechanism. It shouldn't be too hard to slide it back and forth. I slid mine back and forth several times with a screwdriver and after a while it got really loose. JUST MAKE SURE YOU REMEMBER THE POSITION IT WAS IN WHEN YOU TOOK THE LOCKER MECHANISM OFF. This step is critical. Make sure you put it back in the position you found it in! If not, you will screw it up.
Take the locker mechanism back to the workbench. Remove the round clip that holds the outside gear and pull the gear off. Be careful the clip doesn’t fly across the garage when you remove it. Then remove the 3 screws for the housing and then separate the case. You will find a toothed gear with a metal plate on it covered in electrical grease. On the other side will be 3 copper contacts. Look at the attached picture. When you put the casing back together, the contacts “read” the position of the big round gear (the one with electrical grease on it) and know when to stop locking or unlocking (otherwise the locker motor would just keep turning, bind up when it reaches the limit of the torsion spring, and then burn up). So as not to screw up anything, I would put a mark on the toothed gear and the side of the casing. That way if you drop it or move it you can still line it up. IT IS CRITICAL THAT EVERYTHING STAY IN PROPER ALIGNMENT. Some of the electrical grease was caked on with age and that was preventing good electrical contact – that was my problem. Obviously the contact that engaged the locker was working and that was why the locker would engage just fine, but wouldn’t unlock. I cleaned off some of the caked grease and then I bent the copper contacts up so that they would exert more force on the tooth gear and get better electrical contact once I put it back together.
If you want to test the motor at this point you can since it won’t spin the gear and mess up the alignment. I did and the motor worked just fine. When you look at the plug, (the plug that you unplugged when you removed the assembly from the vehicle), there will be 3 pins on one side and two pins on the other. Put 12V DC to the 2 pins side (one is green with a brown stripe and other is green with a silver stripe) and the motor should spin. Mine did.
I put a little grease on the motor’s screw gear and made sure that nothing moved out of alignment on the big round gear and then I put it back together. I installed it back in the truck and it works like a charm. No problems whatsoever.
By the way, when I did this procedure I made the mistake of taking apart the motor as well, which is unnecessary (there is nothing to fix inside), but I didn’t know that until after I took it apart. When you take the motor apart the brushes will pop out and it will be virtually impossible to put the motor back together. If this happens, don’t panic. You can use a piece of string to pull the brushes back in place until you put the motor back together. Then pull the string out. I took a picture of it, if anyone is interested, I will send it.
Hope this is helpful to someone.
Anyway, I have been having problems with my front locker getting stuck in the locked position for quite some time. In my opinion, it is worse if it gets stuck locked then if it doesn't engage at all.
Anyway, my first call was to CDan, who told me that Toyota does NOT sell parts for the locker mechanism. If it breaks, you have to buy the entire thing – which retails for about $600! Well I figured for that price I had to at least try and fix my old one. So I decided to pull the locker mechanism and see how it worked and why mine might not be working. It is not that hard to take off. Pull 1 plug and remove 4 bolts.
My obversations:
First, this mechanism is built very similar to a windshield wiper assembly. It also sees VERY limited use and therefore does not "wear out" like other parts that are moving all the time. Other than it being encased in an aluminum housing (which is softer than steel), it is very sturdy and I don't see how it could break easily. If you have problems with your lockers I am willing to bet that it either needs to be cleaned or the electrical contacts need to be tightened a little (I'll explain later), but I see NO REASON why the entire mechanism should be replaced.
How it works:
When you engage the locker, a motor winds up a torsion spring that exerts a force on a steel pin that locks (or unlocks) the axle. It is normal for this pin to bind up in the axle itself – that’s why the springs are used. The springs keep a constant pressure on the pin until you turn the steering wheel from side to side. This unbinds the axle and frees up the pressure on the pin and the torsion spring then pulls (or pushes) the pin into the proper position (either locked or unlocked). Turning the locker switch on or off spins the motor forward or reverse and winds the torsion springs in different directions so the pin is either pulled or pushed into the proper position. You can see the torsion springs in the picture.
What could go wrong:
Well in theory, ANYTHING could go wrong, but in practical terms, it is usually something simple – and after disassembling it I would say probably one of 2 things. Either the pin is not sliding freely or, in my case, the copper contacts in the locker mechanism aren't making good contact.
Once you pull off the locker mechanism, you will see the pin that engages the locker. You can push it and pull it with a screwdriver. The bottom of the pin will have teeth on them that make contact with the locker mechanism. It shouldn't be too hard to slide it back and forth. I slid mine back and forth several times with a screwdriver and after a while it got really loose. JUST MAKE SURE YOU REMEMBER THE POSITION IT WAS IN WHEN YOU TOOK THE LOCKER MECHANISM OFF. This step is critical. Make sure you put it back in the position you found it in! If not, you will screw it up.
Take the locker mechanism back to the workbench. Remove the round clip that holds the outside gear and pull the gear off. Be careful the clip doesn’t fly across the garage when you remove it. Then remove the 3 screws for the housing and then separate the case. You will find a toothed gear with a metal plate on it covered in electrical grease. On the other side will be 3 copper contacts. Look at the attached picture. When you put the casing back together, the contacts “read” the position of the big round gear (the one with electrical grease on it) and know when to stop locking or unlocking (otherwise the locker motor would just keep turning, bind up when it reaches the limit of the torsion spring, and then burn up). So as not to screw up anything, I would put a mark on the toothed gear and the side of the casing. That way if you drop it or move it you can still line it up. IT IS CRITICAL THAT EVERYTHING STAY IN PROPER ALIGNMENT. Some of the electrical grease was caked on with age and that was preventing good electrical contact – that was my problem. Obviously the contact that engaged the locker was working and that was why the locker would engage just fine, but wouldn’t unlock. I cleaned off some of the caked grease and then I bent the copper contacts up so that they would exert more force on the tooth gear and get better electrical contact once I put it back together.
If you want to test the motor at this point you can since it won’t spin the gear and mess up the alignment. I did and the motor worked just fine. When you look at the plug, (the plug that you unplugged when you removed the assembly from the vehicle), there will be 3 pins on one side and two pins on the other. Put 12V DC to the 2 pins side (one is green with a brown stripe and other is green with a silver stripe) and the motor should spin. Mine did.
I put a little grease on the motor’s screw gear and made sure that nothing moved out of alignment on the big round gear and then I put it back together. I installed it back in the truck and it works like a charm. No problems whatsoever.
By the way, when I did this procedure I made the mistake of taking apart the motor as well, which is unnecessary (there is nothing to fix inside), but I didn’t know that until after I took it apart. When you take the motor apart the brushes will pop out and it will be virtually impossible to put the motor back together. If this happens, don’t panic. You can use a piece of string to pull the brushes back in place until you put the motor back together. Then pull the string out. I took a picture of it, if anyone is interested, I will send it.
Hope this is helpful to someone.
Thanks a bunch
