Rear Locking Dif Assembly Help (1 Viewer)

Well my 96's rear end was not locking so I though I would poke around in something I have never been in before.

So I took the sheld off and remove the front plate of the actuator assembly. When I did this the spring on the plate became un-tensioned.

Do I need to wined up the spring before I put it back on?

Thanks for the help,

how far did you take it apart?

as long as you did not dissasemble the sping from the programing plate and shaft the spring does not need to be rewound, I have some measuremtns and directions at the house I can post later

you will need to take the actuator out of the truck, read the FSM for procedures

I just pulled it off then put it back on. I did not mess with anything else.

Need more info, you just pulled the cover off and lifted in springs slightly and then it unwound? If so you are all right just need to reestablish the relationship between the shaft the spring is on and the output shaft of the actuator

I do not know how to do that with the actuator in the vehicle, do you have a FSM?

Sorry this is hard to discribe.

I did not mess with the spring. I noticed when I pull the cover off something popped and I felt it in the cover that was in my hand. So I figured it was the spring.

I just put it back on, but wanted to take it off tomarrow, Sat., to see what you are talking about. It sounds like you said, I need to wined it to get it in position.

I wish I had a FSM.

Thank you for your help,

the actuator holds constant tension in both the locked and unloked positions you just released that thension, unfortunatly that screws up the timing between the parts, what is you E-mail address? I'll send you some files to help with the removal

warpdriv, the following is not spacificly for you, I started it a long time ago just jot off my ass today and finished it, you will have to use my measurements as you have already lost the relatioship,


Rear locker actuator disassembly and reassembly
This was written from poor notes and beer soaked memory several months after I did my actuator, if there are any errors please let me know

The FSM does not give info for disassembling the actuator, only removal and installation. Toyota services it as an assembly, none of the internals can be purchased separately. If you damage the actuator or find it damaged you must repair the part or replace the whole actuator witch is expensive. For the most part the actuator can only go back together one way, careful observation of how it came apart will get it back together except for one thing: the relationship between the “final gear” and “shift lock fork shaft” witch should be measured before disassembly that if not possible use what I measured

The locker ECU sends power to the motor witch turns the drive gear and then the driven gear, witch winds up one of the 2 wait springs, attached to the driven gear is a metal programming plate, the contacts ride on the plate, the center one is always in contact, the other two ride onto plastic areas and open when the driven gear “locked” or “unlocked” position, the locker ECU sees this and turns off the power to the motor, most of the time the locker is not lined up when you try to lock it, that is the purpose of the wait springs, they apply pressure in the locked direction after the motor turns off waiting for the locker to line up and drop in (difference in rotation of the rear wheels) , the same thing happens in the unlock position where there may be “driveline windup” loading the teeth of the locker preventing it from traveling, the wait springs wait for it to unload and pull the locker to the unlocked position, for this all to work right the programming plate that the locker ECU watches that is attached through the wait springs to the final gear and the “shift lock fork shaft” must be clocked properly as they can be meshed together in may different combinations

You will need common hand tools, hammer sockets screwdrivers etc , non-conductive grease (I used standard wheel bearing grease), an ohm meter one with alligator clips or a helper to hold, a good fine scale rule or better yet a dial caliper for taking length measurements.

First remove the actuator from the rear axle remove and clean the exterior. Work on it somewhere where small parts will not be lost. Your cluttered workbench may not be best

Do not remove the main body cover at this time, Remove the 3 Phillips screws from the motor cover, slowly pull the cover off as a lot is about to happen, there is an O-ring underneath that may stick you need to salvage it in one piece or you will have to find a US equivalent to a metric o-ring (difficult), the motor armature may stay in the actuator or may stick to the 4 magnets glued in the cover, if the armature comes out with the cover the motors brushes will be dislodged it would be a good Idea to take a look at these as they come apart to help with reinstallation, there are 2 small springs behind the brushes that will push them out and then fall out themselves, DO not loose the springs, the brushes are attached by very thin braided copper wires, be careful with the wires they look fragile,

If the armature stayed in place gently rotate and pull to see if it will stay, best for it to come out when you are expecting it,

Looking at the actuators electrical connector ( R 9 ), the picture of R9 in the EWD is of the body side harness the actuator is a mirror image of it.

With the locking tab up the two rows of pins are:

32x
654


X NC
2 green
3 green/red
4 black
5 yellow
6 green

We are interesting in 4 common, 5 open when unlocked and 6 open when locked
Check for continuity between 4&5 and 4&6 if both have continuity then the actuator is either in transition, neither locked or unlocked or over traveled (beyond the plastic areas), start with the unlocked position (continuity between 4&5) rotate the motor if installed to retract the “shift lock fork shaft” if the motor is not installed just slowly push on the shaft until continuity is broker between pins 4 and 5, at the exact spot that it breaks open measure the amount of exposed shaft, mine was 2 3/16”, rotate the motor (if installed) the other way to extend the shaft or pull it out until continuity between 4&6 is broken, this is the locked position mine was 2 7/8”

Now you can pull the 3 bolts holding the main cover, inside the wait springs, driven gear, final drive, and programming plate will come out as a single assembly, Try to keep them that way, note the bevel on the final gear for reinstallation as it can slide off the assembly, there is also a small metal tab in the shaft purpose unknown that can fall out, clean off any corrosion and old grease dirt ect with contact cleaner, or alcohol,

Look everything over repair any damage

Put a dab of grease in where armature shat contacts the motor cover and where it contact the main housing on the other side of the drive gear, also on center of the main cover that supports the cross shaft and matching spot in the housing, grease the drive gear, driven gear, final gear and shift lock fork shaft, also grease the o-rings and their grooves to help sealing, and a thin layer of grease on the programming plate where the contacts ride

Make a mark with a sharpie or grease pensile on the housing where the contacts are that will be visible during assembly, also mark where the plastic areas are on the programming plate on the back side of the driven gear that are visible during assembly, the plastic areas are about 120 degrees apart, the contacts normally travel in this small arc not the larger 240 degree arc,

Insert the “shift lock fork shaft” until the rings or gears on the shaft are approximately centered in the housing, install the wait spring/final drive etc assembly in the housing with the contact mark approximately in the middle of the two plastic area marks, and temporarily install the cover, rotate the motor (is installed) or push the shaft in and out wile watching for continuity like above, it may take a few strokes for the contacts to cut through the grease and make good contact, if the measurement is not as above take the cover off lift out the final drive assembly and move it one or more teeth over as required, reassemble and re-measure, repeat until your measurements match,

Reinstall the greased o-ring on the cover and tighten the three bolts, might be a good idea to recheck you measurements again
If your motor came out, make some clips our of light gage wire to hold the brushed back against spring tension, slide the armature in place and rotate it when the drive gear contacts the driven gear to let it seat, pull the clips and the brushed will slide into place install the o-ring and the motor cover, make note of the 2 small locating nubs pressed into the sheet metal of the cover, it is possible to install the cover incorrectly if you do not match up the nubs to the holes in the main housing

Clean and paint if desired

Here is my email: warpdriv@yahoo.com

Man, I can not thank you enough for helping me.

Just got done refurbishing Her rear diff lock actuator, thanks Raven for your insight, invaluble...

The rig in question is a new to Her '96 LX450 with 125k, I bought it knowing the rear was not locking and that it was a common, fixable problem (and leverage against the seller). After some time in the archives and driving around in circles I took it apart, found that a PO tried his hand at a refurb also. The magnets had been reglued, O-rings lost, and as it turns out reassembled incorrectly. I marked eveything, took measurements, got all scientific and everyhing, wouldn't work the PO's way, then I started from scratch with the help of Raven's post. Using all of his measurements I was able to get it working, it would extend and retract when I jumped it (briefly) from the battery, when hooked up to the wiring harness I would only get a little movement in the wrong direction (clockwise or plunger IN when I switched to lock). Take apart/put together/take apart/put together...same thing...so I get super scientific and break out the EWD...to make a long evening/not so early morning of trouble shooting short: turns out somehow the motors polarity is reversed. Lock juice from the computer to pin 3 at the motor had the effect of UNlock juice on the motor...cut the wires on pin 2 and 3 on the motor pigtail and swap 'em, now all is well....

This thread might do well in the FAQs

Magnets may be been installed upside down, causing the reversal.

wow old thread, Glad it is still helping.

Oh yeah, with your help the FSM and EWD just paid for themselves...if not FAQ then tech links...

well now that i have a star some pics,

swapped magents sounds like a good posibility, also did you get the cover the magents are mounted to lined up propperly?, I do remember some small line up tabs

Two of the three ears on the motor cover have little dimples in them with corresponding dimples on the case, mine is on right....why the motor acted in reverse is beyond me, I'm just happy I found it and made an easy fix

When Jeff owned his 80, he hadn't ever repaired the rear actuator....I purchased the rig and a baggie with a couple parts were included.

Between the FSM and a nice sunny day this past summer, I went through and figgered out how the spring system worked and what the orientation was. It locks fine now, tho it is a little finicky when it's colder. Never had to removed from the vehicle, just pulled the 3 screws from the round cover 4-5 times while I experimented with it.

A couple of questions, as I'm about to start on mine. Being in a 'baggie with a couple of parts' condition, I would like to find out/confirm:

1. the 'final drive gear' goes with the bevel up (towards the cover of the actuator) and with the flat side down (towards the bottom of the case), right? That's what it looks like on the diagram...

2. what is this 'small metal tab in the shaft purpose unknown', what does it look like and where, exactly, on the shaft does it usually reside?

3. RavenTai, where did get you get the diagram of the actuator? Thank you for the writeup, the diagram and the pictures.

1. it was 2 years ago, I remember the bevel on one side you are talking about but not witch way it went, maybe drop the gear and the shift lock fork shaft into the housing and see witch way gets the most tooth engagement and see if everything clears.

2. at the end of the driven gear cross shaft was split, the end where the final gear lives, this tab just sat there filling the split in that shaft, at the time I could not figure out what it did, so I put it back where it came from, I mentioned it above just so people would be aware of it and not loose it, it is just a flat piece of metal maybe 5/15" wide and 1/2" long or so?

3. the diagram comes from the 96 LX450 New Car Features manual in PDF format, a very interesting manual, it talks about how things work with drawing and schematics, no instructions on repairs just "how it works"

each time a model is redesigned a full NCF is produced for that year, after that only changes are discussed, so if you have a 97 LC you need each manual from 1991 on to get the full set, for instance for your 97 to see the body info you woudl go to the 91 manual, for the interior the 95 manual, for the engine and lockers the 93,

since the 96 LX was a "brand new vehicle" as far as Lexus was concerned a full NCF was produced for that year, if you own any year FZJ80 it is the one to have,

here is the transfer case section from that manual


http://webpages.charter.net/raventai/HF2AV TRANSFER.pdf

Ok, let's make this another "long Live RavenTai!" post.

1. The measurements as given work. The picture was worth a few words as well.

2. My driven gear cross shaft was NOT split and therefore I'm assuming that the little tab I'm missing is something that I'm supposed to be missing (my e-locker came out of a '93, I was told). I guess the Lexus is superior...

3. I set the Shift Lock Fork shaft to the distance RT gave (2 7/8") and moved the prgramming plate around until I could move one tooth CCW and break the connection and CW and make the connection. I left it at the first toth that broke the 4-6 connection. This gave me a fully functional locker once assembled; using a 9V battery didn't give me enough juice to wind the springs enough to allow the programming plate to do its worl. Oh yes, it helps to put the fork in before re-installing the actuator
I never took the motor apart, so I cannot testify to that part of the instructions.

Thanks again!

Glad it worked for you

What would be the best way to test the actuator be it electrical or some other way to guarantee it will work perfectly when installed back onto the 3rd?