Center Differential not engaging (1 Viewer)

[oldrider69]

Hi
I'm new on IH8MUD...I know you guys know a lot about Land Cruisers, so I decided to post a new thread looking for "enlightenment" from anybody on the problem I'm facing with my 1997 TLC 40th AE....my Center Differential/Transfer Case does not engage and consequentially doesn't lock the Front and Rear differentials.

Here is a little history:
I bought the truck about a month ago, and since I didn't know much (I still don't ) about how the 4x4 system works on these trucks, I never checked if the CDL was working, so after doing a little research I kind of understand more about it.
I drove the truck and try to engage the CD/Transfer Case with the Hi/Lo shift on-road and off-road, and I didn't notice any change in traction, other than the Transmission changing to low gears...after this I kind of suspected that the truck wasn't locking, but I wanted to make sure and decided to do a couple of more visual and mechanical tests.
I did some troubleshooting to the system by doing the next, while in Low:
A.- I drove the truck around in tight circles and I don't feel the tires struggling or having a hard time rotating, in other words, it's the same as it was in Hi.
B.- I also lift one front tire and turned it manually and it rotates with no effort.
C.- The 2 lights on the dashboard that supposed to let you know the truck is locked, ABS and Differential Icon, they don't light up.
So definitely the CD/Transfer is not locking, so I decided to put hands in motion, after some research on several forums and asking here and there, this is what I've done:
1.- Checked the CDL Indicator Switch and it works.
A.- I took it off the top of the Transfer Case, disconnected it from the plug and checked continuity. Good.
B.- I bridged the plug with a piece of metal and lights on the dashboard lit up. Good.
C.- I plugged back the Switch (with out putting it on the Transfer Case) and used a pair of pliers to press it while it was plugged, and the two lights on the dashboard lit up.
So I guess that takes care of the CDL Indicator Switch, right? (attached a video for reference)

2.- I checked the Transmission Relay and it works.
A.- I engaged the Hi/Lo shifter to low and I can hear the Relay "clicking". Good.
B.- To make sure it was working, I removed it from the left kick panel and opened it, I checked continuity following the Factory Repair Manual, and is within the specs. Good.
So I guess that rule out the Transmission Relay. Right?

3.- I checked the Actuator Motor and it works, I think?
A.- I took it off the top of the Transfer Case and test it with external power, and it rotates well. Although I notice that it only rotates about 3/4 of a turn. (video attached)
B.- So I put it back in place and while unplugged, I applied external power with a 9V battery and it rotates well. Plugged it back.

Conclusion...after doing all these, and confirmed that the Lights on the Dashboard, the Transmission Relay, the CDL Indicator Switch and the Actuator Motor are working, I still can not lock the Center Differential!!

What am I doing wrong?

Thanks for your patience guys, and hope you can help me.
Carl.

 

[Beerson]

I had the same problem and tried all the same things that you have. In the end, what worked for me, was changing out the fluid in the differential and then using low. I had to turn around on a narrow dead end road and I did it in low. Glad I didn't break anything but about 3 turns into my 6 pt turn, the light turned on and it felt different and its worked ever since. Not sure if that helps, but that did the trick for me.

 

[oldrider69]

Thanks for your reply Beerson
...you know, my thinking was that I would have to remove the Front Extension Housing on the Transfer Case in order to gain access to the Shift Fork number 2 and see if there was something wrong with it...I guess it would be a good idea to change the oil just like you did first and then take it from there.
By "using low" you mean like use the Low more often and drive it around for a while, or what?....because I used the Low for a couple of times but not drove for too long.

 

[Beerson]

I had put it in low several times that day for short periods of time where I thought I might need it. The last time in particular was a long steep-ish path with bigger rocks so I was in low for some time and had to turn around at the top of the road. That's when it engaged for the first time.

My thinking was I just bought this truck with 200k miles from a family who's owned for over 15 years and they said they never once engaged low because they "didn't know what it did". I assumed it was probably gummed up. First thing I did when I bought it was change every single fluid in the truck. They took care of the truck but it was a soccer mom vehicle to them...it was probably never driven over a curb on purpose

 

[oldrider69]

I think we're on the same boat, or better saying, I'm the boat you were before...I also bought the truck from a family guy who owned the LC for 13 years, old guy that used it to drove around with his grandsons, so basically didn't use the CDL....
After reading your comments, everything make sense, that's is probably my problem too, lack of usage...after all that old saying may apply here..."use it or loose it". Hahaha.
Alright, so I will change the fluid, drive it around in Low for seveal times, and see what happens.
I'll keep you posted man.
Thanks a lot.

 

[CoffeeGeek]

Did you try manually locking the center diff with the actuator removed? The center diff lock as I recall should be installed in the locked position. With diff lock removed jack up one tire and reach into transfer case. There is a gear thT you rotate to lock while you turn the lifted tire with your foot. You will feel the transfer case lock when doing this.

Does the actuator rotate when removed but still plugged in and signal sent to engage? Maybe remove your hazard switch and use the switch in plug provided to have a push button to engage center. This simplifies trouble shooting as you do not have to manually engage low.

 

[oldrider69]

Thanks for the reply Coffe...
To answer your question, no, I didn't try to lock it manually, didn't know I could do that...so you're saying that with the Actuator Motor off the Transfer, I can reach in and move the gear and have somebody (or my foot) rotate the lifted tire and it should lock...
Also, to be honest, when I read the FRM it says that you have to install the Act. Mot. in a Lock position, but I thought it refers to the motor and not to the Transfer Case...so what needs to be in a "locked position" is the CD/Trans. Case...ahhh, ok...sorry for my ignorance!
Ok, that is something else I will try, definitely!

On your second question, I did not try the Actuator off the CD and plugged, what I did was removed it and bench tested with a battery, and it rotated, but just 3/4 of a turn....is that enough to engage the Locking gear?
And as to your last comment, and I do apologize for not mentioned it before, I do have installed a CDL Switch on my LC, I did the installation my self and it works, meaning it does send the information to the system (Transmission Relay clicks and Actuator rotates) to "engage" in Hi, but the CD doesn't engage, just like in low.
So remove the Actuator (again, sigh), reach in the CD and lock manually, install the Actuator back in place and try to engage with the CDL switch, right?

 

[CoffeeGeek]

Thanks for the reply Coffe...
To answer your question, no, I didn't try to lock it manually, didn't know I could do that...so you're saying that with the Actuator Motor off the Transfer, I can reach in and move the gear and have somebody (or my foot) rotate the lifted tire and it should lock...
Also, to be honest, when I read the FRM it says that you have to install the Act. Mot. in a Lock position, but I thought it refers to the motor and not to the Transfer Case...so what needs to be in a "locked position" is the CD/Trans. Case...ahhh, ok...sorry for my ignorance!
Ok, that is something else I will try, definitely!

On your second question, I did not try the Actuator off the CD and plugged, what I did was removed it and bench tested with a battery, and it rotated, but just 3/4 of a turn....is that enough to engage the Locking gear?
And as to your last comment, and I do apologize for not mentioned it before, I do have installed a CDL Switch on my LC, I did the installation my self and it works, meaning it does send the information to the system (Transmission Relay clicks and Actuator rotates) to "engage" in Hi, but the CD doesn't engage, just like in low.
So remove the Actuator (again, sigh), reach in the CD and lock manually, install the Actuator back in place and try to engage with the CDL switch, right?

Yes go back in. The amount of turn sounds correct. The actuator and center diff need to be in locked position when you install the actuator. Use a mirror and look inside the transfer case. You will be able to see the gear you will mannually turn to lock. The turning of the tire is key to get it to click in and fully engage.

 

[oldrider69]

Ok...
Just one more question...howe do I know the Actuator is in locked position?
FYI, there is 2 marks on the little gear on the Actuator that I noticed, my asumption is that those 2 marks needs to be lined up and that means is in locked position?

 

[CoffeeGeek]

I don't remember. I made an error once and had to redo the work. I figured the way the motor has to turn to actuator the gear that loads the fork.

Had a bit of difficulty with CDL, my brother helped me damage the first one by tapping on the motor housing with a hammer. If a little bit of tapping was good more was better. Lol. I bought a second used one and it ended up having loose magnets as well. Fixed that and installed. I believe that is the one I put in unlocked, out it came again and then back in ensuring all locked up. It would not hold locked and would occasionally pop out. Out again and found the spring mechanism was damaged. Had to make one good actuator out of the two I had, now it works great and I am happy I am 3x locked.

 

[oldrider69]

Yeah, I think what I'll do is:
I will remove the Actuator, look inside the Center Diff/Transf Case and figure which side of the rotating gear (in the Actuator) is "touching" the Locking Rod (Shift Fork No.2 Shaft on the Service Manual) inside the Transfer Case. Once I figure that out and by knowing that the Locking Rod needs to be pushed forward in order to Lock the CD, I can determine the "Locking Position" on the Actuator....then I can rotate it with the 9V battery and set it accordingly.
...sounds pretty easy, hahaha, will see what happens.
I will keep you posted on my results guys!
Much obliged.
1997 Land Cruiser Center Differential Actuator Motor

 

[oldrider69]

Hi guys...well good news.
I did what you recommended and it worked!
I removed the Actuator and reached in to it to move the Gear Wheel, this toothed wheel will move the Shift Fork No. 2 Shaft which
will avtivate the Shift Fork No. 2 and engage the differential.
While rotating the Gear Wheel with one hand counterclockwise, I was spinning the front wheel on my LC until I Locked the differential, it was a little difficult at the beginning, but after 2 or 3 times of lockin it and unlocking it, it went easier.
I left the Differential in "Locked" position, made sure all Lights were lit and CDL Switch work, I put my Actuator in "Locked" position too, installed the Actuator back on....before I test drive it, I change the Transfer Case oil (the oil was nasty, pitch black and kind of gummy...thanks for the tip Beerson).
So after 5 hrs of hard work, test drove it and everything is working perfect!
I just want to say Thank You to both of you, you guys helped big time with your advise.
...later.