Rear diff locker will not engage (bad actuator?) - Help

My rear diff locker will not engage in my 2004 TRD. Before anyone says anything, it used to work so I know how to use it properly.

So here is what happened: I tried to get it to engage by driving in figure 8s forward and reverse on a snowy/icy parking lot. I could hear the actuator/motor make a noise when I hit the button. It never engaged and the light just kept blinking.

Now, I cannot even hear the actuator make any noise when I hit the button.

What broke? The actuator itself, a switch, a solenoid? Help please!
Is it time to take it to Toyota? I hate the dealership because of the cost, but are independent shops going to know how to work on this?

Thanks

 

Dont know if this will help you or not but BFF BILL's locker stopped working while ago and here is what he had to say about it. He's 2nd Gen though

Goodluck!

 

I had the same issue.


Take the actuator off the diff, and make sure to disconnect the breather tube and electronic connection. If the gear that engages in the diff is seized, try this:

Remove the 3 screws from the aluminum plate that faces the diff housing. Hit the inside of the actuator housing with some PB blaster and that gear will loosen up. You can pop the gear off by removing the snap ring that holds it on so you can get a good grip with vise grips on the shank to twist it some.

That should do the trick - it just needs to be loosed.

Give me a sec and I'll give you better instructions

EDIT - BETTER INSTRUCTIONS
1) Remove actuator from diff housing.
2) Your actuator is in the unlocked position; mark on the gear and the housing the 12 o'clock position, so you can get it oriented back on the right way.
3) Remove snap ring and gear on actuator; set aside these two parts.
4) Remove aluminum plate that makes contact with the differential. There are 3 screws if I remember right. This plate may take some coaxing to get off.
5) Remove the rest of internal components, making sure you know how to reassemble it.
6) Hit the base of the shank (the part you took things off of in step 3) with PB blaster. Let it set, and then grab ahold of the shank with vise grips and try to twist it. Add more PB blaster and repeat until free.
7) Check contact points and make sure they are clean. Use dielectric grease (Marine grade works) to coat parts.
8) Do not remove the other housing on the outside of the actuator - the part that sticks up and is black, held on by three smaller screws. This reveals the motor; no need to get into that, at least not yet.
9) Reassemble, using RTV sensor safe sealant when you mate the aluminum plate back onto the rest of the differential housing. Make sure the gear you marked earlier is in the same position.
10) Hook the electronic hook up to the actuator, but do not mount the actuator.
11) Cycle the actuator from the cab (with the button). Leave it in the locked position.
12) Raise rear axle up on to jack stands, and chock the front wheels. With the emergency brake off, use a flat head screwdriver to move the rack gear inside of the diff to the left, to the locked position. You make need to move the drivers side left wheel some to get the rack gear to move. It is in the locked position if both wheels spin the same direction when you rotate the wheel by hand.
13) Now that it is in the locked position, reinstall the actuator. Put the vehicle back down.
14) Test it out.

 

Mike, did yours also stop making the noise when you hit the button? If you could give me some better instructions, it would be much appreciated. I have not worked on the actuator before but am fairly mechanically inclined and do not mind turning a wrench, although the road salt from the last eight years might be a PITA when removing everything.

Edit: A little too late on my post. Thanks for the instructions. looking them over now.

 

What kind of noise are you talking about? Did it sound like a chattering from under the hood? What other instructions do you need? I'll see if I can dig up a write up.

Ya, the road salt can be an issue. Mine wasn't too bad, but some screws took some work.

 

Here you go. My write up is a hybrid of all these. http://www.tacomaterritory.com/forum/showthread.php?t=42460 - This is probably your best bet.

http://personalpages.tds.net/~thompson_wp/tacoma/locker.htm

 

You can normally hear a noise coming from the actuator when you hit the rear diff button. I think it is the motor trying to engage. You can then hear it again when you hit the button to turn the rear diff lock off. Mine does not make any sound now so I hoping I did not fry the motor because the gears were locked in the actuator.

Did yours also stop making any sound when you hit the button?

 

It should make some sound; if you are not hearing anything, you may need a new fuse. In your fuse panel (left side of steering wheel, down about 6-8 inches, you'll see it) there is a 20 amp fuse, in the 4wd slot. It also controls the actuator. It may need replaced.

 

I had the same issue with my '99. Remove the actuator, disassemble it and inspect the steel shaft that is in there. The housing is aluminum, and over time, living in the salt-belt, it corroded and seized on the steel shaft preventing anything from moving. Clean the housing up, degrease it, fill any cracks/holes with epoxy and repaint it with a good paint. Lube the actuator gears (plastic) with an appropriate grease and reassemble. Hope this works. It made mine work smoother than new.

 

Sorry. Little confused now. I used to hear a sound when I engaged and disengaged the locker. Now, I hear nothing.

Did you still hear the sound of the actuator, but it would not engage? I will check the fuse, but if it is for 4wd also, my 4wd works just fine so kind of doubt that.

I guess I do not understand if it is possible to 'burn out the actuator' or it will just get stuck and not move anymore, hence no sound???

Thanks

 

I misunderstood you earlier.
If you are not making sound, then that could be because the actuator is seized. However, mine still made sound. You may need to tear into the motor on the housing. One of those write ups in the links give some detail with that.

In other words, it should make sound, even if it is stuck solid.

 

I was specifically looking for this exact link, but I must have deleted it. (http://personalpages.tds.net/~thompson_wp/tacoma/locker.htm) Worked like a charm.

 

Thanks for the links. Seems like it will be a pretty big job. Any idea on how many hours I am looking at for those of you who have done this?

Anyone ever try to find one at a salvage/junk yard from a totaled truck?

I either need to find a garage or wait until summer as this is my daily driver and I really dont want to be laying on my subfreezing driveway right now!

 

How long will it take? I took the actuator off the truck 5 times before I found the links. Once I found the links, it took 2 hours to meticulously go over everything and check the motor on the actuator as well. If I hadn't taken it off before and tore it apart before, it would have taken 3 hours. So bottom line, expect to take an afternoon to do it right. Could take less, depending on the condition of the locker.

I looked at salvage yards/junk yards and found no parts in a 50 mile radius. 1998-2004 will work for you. Should be 4.10 gearing.

You just need a work bench. Pop the actuator off - 5 bolts/nuts, including the cover. Take it inside and tear it apart. Don't need much space.

 

Also, I believe the part is $750 new from a dealer. If the dealer installs it, you're looking at around $1000. Having a non-functioning locker reduces the value, essentially by $1000 to a prospective buyer interested in a functioning locker.

 

Thanks for the info. I plan on either rebuilding it myself or finding a used replacement from a salvage yard or from someone who is parting out their truck. Probably not going to be easy to find so will have to set some time aside to fix it. Did you have to do the step where you hook it up to some batteries (I was just skimming over the links you provided and saw that somewhere)?

 

Rebuild that thing. Its easy. I was in the same boat as you, push the button... drive in circles, figure eights, ect... and nothing. Not even a sound when pushing the button.

Took an afternoon and rebuilt it and she works great. (would have been 2-3 hours but I snapped one of the small bolts that holds the cover on and had to drill it out). There were two issues with mine. First was I found a piece of metal in the "gear" that comes directly out of the electric motor... dont know if it was there or not before. Second problem I had was that all the grease on the inside had dried up into powder.

Take your time and be care not to snap the two little bolts that hold the backing plate onto the housing and not to damage the plate as you pry it off.

Get some good grease to rebuild it with, and a nice gasket maker to seal it back up with because your probably going to wreck the gasket.

Its pretty easy to do. As for checking the functionality of it. Pull the locker off the axle and plug it bag in and then have a buddy push the button with the power on (engine need not be on if I remember correctly) if it works the gear will spin... and you probably have something up with the plate gear in the axle or somthign is misallingned. If there is no movement or noise then you may have a electrical issue.

Mine made no noticible noise when attached to the axle, but when it was off the axle you could see it was trying to engage but could not spin the gear.

We did not pay attention to how we pulled everything apart so we put it all back together and locked and unlocked it a few times and the actuator seemed to "recalibrate" its self.

Then as others said, jack up the driver side rear and spin the wheel to make sure its unlocked... then use a flat head screw driver to manually slide the plate gear into the locked position, then check that the wheels is locked.

make sure the axle is in the locked position as well as the actuator and put it all back together.

All the links and instructions should help.

This is the walk through I used. Check out the pictures too they help. I was expecting my locker to look like his since my rear axle is super rusty... but mine was in pretty good shape.

 

Ya I know what you are talking about. I didn't hook it up; I had it reassembled exactly as it was, and had there been something wrong, I would have found that out when I hooked up the electrical connection on the rear end. In my opinion, not a necessary step.

 

Ok. Going to try to rebuild it when I have a free day on the weekend. Really need to look at the condition of the bolts/nuts on the housing as the truck has seen a lot of salt. Would hate to break them. Anyone know what torque they are at?

 

Update: I rebuilt the actuator. The shaft was seized to the aluminum housing plate. There was also a nice hole in the plate that I had to seal with JB weld. I got the shaft to spin freely and hooked it up to the electrical connection to test it. After some difficulty (at first it locked and then would not unlock), I got it to work and bolted it back to the diff. Everything worked. It was locked when I restarted the truck, backed it out of garage, unlocked in the dirt, disengaged 4 wheel drive, and tested everything twice.

Problem: It has been one week and I went to some trails this weekend and it would not lock up. It makes noise like it shaft is turning, but the light just blinks. Anybody have this problem after rebuild? Suggestions?

I am going to take take the actuator off the diff this weekend and test it again.