DIFF LOCK Light ON!! Cant turn it OFF!!! HELP!!!! (1 Viewer)

[FloridaFJ80]

Well I have been having this problem for a while now. I have been driving my truck with the Center Differential locked. I have searched and read and troubleshooted everything that i can try to fix this problem.

It all started when i would drive my truck and do tight turns i would hear the clunking and banging noise in the front. Its embarrasing especially when there are people around and the see this nice rig with some really bad noises coming from it.. Keep in mind i dont have any Diff lock indicators on in my dash, i just know they are locked. So i read around and i troubleshoot that it could be a bad switch, so i go ahead and order a new CDL switch. Put it on, and nothing happens. no lights...... nothing!!!!!!

So i continue to drive around with this problem, its my DD so i have no choice. I continue to read around and i read something about not getting any indicator lights on the dash, like the DIFF LOCK light. I dont have the ABS light cause i have a 92 FJ80. In the thread the guy had the same prolems as I did, no lights, locked differential = load noises.. He did a paper clip test to the switch on top of the Transfer case, and low and behold he gets some warning lights on his dash again. he got the 4lo indicator switch from CDAN, and if i remember correctly it fixed his problem.. I try the paper clip test and i get some new lights on my dash again.

I give CruiserDan a call, order the indicator switch, got it in this morning, installed the new switch.... Get the DIFF LOCK light back on... Push the CDL switch to turn it off, nothing happens!!!!!!!!!!!!

So after getting to new parts installed, i still have the same problem, just have the DIFF LOCK light on and i have a locked center diff and no means of unlocking it...

I need your help fellow Ih8muders..... What can i do now?????

 

[cruiserman]

Short term solution is install a set of manual hubs. Do you have a service manual? I've not had to troubleshoot my t-case, but there should be a section in the manual on it.

 

[FloridaFJ80]

i do have the FSM manual.. but i havent found anything on troubleshotting a locked differential...

 

[Brentbba]

I may have been that paper clip king, but no push button on my '94 so can't help. Just feel your pain. Are you saying you think you are driving around in 4lo all the time? You'd feel that big time. Dash switch bad?

 

[wob]

Are you sure that the diff is locked, and what you are hearing isn't just bad birfields?

 

[e9999]

there is an old thread on this that I think I started and ended up with some solutions on how to unlock manually.
But anyway, can't you just unbolt the cover and just pull or push on the actuator?

 

[FloridaFJ80]

I read my FSM under the Tranfer Case. this is what it says when the light doesnt turn off.

HINT: There are times when the light will not go off unless the sterring is straight ahead and accelaration and decelaration are performed slowly.

There is nothing else... Looking at the diagram of what makes up the transfer case, there is a motor actuator, the 4WD indicator switch, in the front of the transfer case, that turned on my diff lock light on my dash..and in the back there are two switches located in the rear extension housing, one is the L4 position switch and a neutral position switch.

Also does anyone know how i can grease up my birfs, to prevent some some damage...????

Are you talking about the hubs that Slee sells for the part -time 4WD???

 

[Tools R Us]

I had a problem with the wiring at the transfer case.

https://forum.ih8mud.com/showthread.php?t=59333

Oops linked to the wrong post!

 

[FloridaFJ80]

When i make tight turns, my front and rear tires slip in the pavement, they squeal pretty much as well as the clunking noise in the front.

WOB - Is there a way to check physically if i have bad birfs, cracks, leakage,etc???

e9999 - If there is away to manually unlock the diff let me know.. I want to fix this before anymore problems arise...

BrentBBA - I am not driving around in 4LO, my transfer case lever is in HI, but my Diff lock light is on.. I think it was your thread that i read to troubleshoot mine... LOL

 

[CJF]

i do have the FSM manual.. but i havent found anything on troubleshotting a locked differential...

First of all you need to ABSOLUTELY verify your center diff is locked by jacking up the vehicle and confirming this.

Second, I haven't had to face this problem yet so I'm not 100% sure, but I thought the diff lock was controlled by a vacuum solenoid. If so, there ought to be a procedure in the FSM for testing the solenoid. In fact (this is just a guess), I *thought* I heard of a trick where if it goes out and defaults to locked, you can reverse some vacuum line/lines as a temporary fix. (Take this last sentence with a HUGE grain of salt.)

Curtis
91FJ80

Edit: 2nd paragraph may only apply to an FJ62. Just graspin' around since you seemed desparate.

 

[Beowulf]

I agree with Eric (E9999) that you should be able to manually disengage the center diff lock actuator; perhaps using a small 9v battery along with the EWD. If you don't have the EWD and can't find the right wires then ask for someone to post up the center diff lock pages from a '92 EWD.

CJF... The center diff is electronically controlled; not vacuum... but you're on the right track.
-B-

 

[FloridaFJ80]

Tools R Us - I am thinking that could be my problem.. I would need a new one or used one from CDAN.. How much did it run you?>? So basically take the old one off and put the new one since mine is already locked??? Is there a way for to troubleshoot that before i go ahead and buy a new one?

EDIT: Do you think i should look at my transmission relay first?????

 

[Brentbba]

If your tires are chirping while turning on pavement, you are indeed locked up either front or rear. You wouldn't hear any chirping if just in 4lo.

Ah hell - just take a BFH to it. Just kidding.

 

[FloridaFJ80]

Beowulf - I do have the EWD for my rig. I am not electronically savvy and I cant really interpret the EWD to its full potential.. But i can try it.. Just would need some sort of guidance..

Thanks alot guys keep the ideas coming...

 

[FloridaFJ80]

Is the center differential lock relay the same as the transmission relay in the pin 7 mod???????

 

[Beowulf]

Just would need some sort of guidance..

Your best bet is to wait for Kevin to give you guidance. In the interim you might familiarize yourself with the wiring to the actuator. He has tested and been inside that component and most of us haven't.

-B-

 

[alkaline747trio]

The clunk IS a bad birfield, the cause MAY be a locked center diff. Why not just remove your front driveshaft, and see if you are locked. If you ARE, then this is a temp. solution untill you can find how to unlock it. That or a permanent solution, just be stuck in 4x2.

 

[Tools R Us]

Oops I posted the wrong link above, forgot I had to go in there twice!

The "clunking and banging noise in the front" sounds like a bad birf, but they usually don't go far before you have no drive and doesn't explain the CDL light?

If the CDL is locked you usually only get some tire scrubbing, chirping. The CDL staying locked could be the motor, relay controller box, wiring or switch. The FSM has a good troubleshooting tree for testing the parts.

 

[Tools R Us]

First if you need to drive it remove the front driveshaft, so you have two wheel drive.

Then test the center differential lock relay / transmission relay and verify that you have the proper output to the actuator. If your getting proper voltage down to the actuator, it's probably a bad actuator.

 

[FloridaFJ80]

Ok i will remove my front drive shaft... where is the center diff lock relay located, is it next to the transmission relay???