Locker Doctor anyone? (1 Viewer)

[jamot]

I just picked up a 93 with the optional lockers...... Non working that is..... Shift to low, turn knob, blinking locker indicator lights that continue to blink after moving forward etc....

I'm sort of a "locker dummy" but I'm assuming from using my 98 with rear locker the indicator light should stop blinking along with the abs light coming on indicating lockage and disabled abs.

I'm pretty sure this baby spent the first 243k of her life as a mall cruiser due the the sour milk smell and probably saw very little use of low range and locked diffs. The t-case shift lever is very stiff too...

My question...... Can someone direct me to some good reading (outside of the fsm) or a thread I missed in my search to educate myself about the locking diffs and how to diagnose and fix non working ones?

 

[TOY350]

Get in some gravel or somewhere you can cause a wheel to lose traction, the tires (front or rear) must turn at different speeds to engage the lockers. If you turn in some gravel or try a hillclimb where you lose traction the lockers should engage if they are working properly.

 

[-Spike-]

The center differential lock (CDL) must be engaged before the axle lockers will engage. Either push the CDL switch (if equipped) or put the transfer case in low range. The yellow center diff lock indicator on the dash should light, and must be lit for the lockers to engage. Yes, flashing red indicators only indicate switch position, a solid red light will indicate that the axle locker has engaged.

Got CDL?

-Spike

 

[jamot]

Thanks Toy350. I'll take her out later and do that.

I thought non use may have played a role, but I'm spread pretty thin with several projects, so it's hard to spend a lot of time on a new one right now......

Although I must say I am happy to have aquired this rig, and look forward to "getting her in shape" time permitting.

 

[jamot]

Spike. No CDL switch on this one... yet. Yellow indicator does come on when I shift to low.

Like I stated earlier, I'm a factory locker dummy, with knowledge only based on how the rear diff lock in my 98 100 series works.

I wondered if a lack of use would make a solenoid stick, and it may not be related, but man you really have to muscle the t-case lever into low..... not a mechanical resistance, but more of a "I've never had my linkage lubed" feel.

Oh yeah... ABS light should come on to indicate disabled ABS like on my 98 right?

 

[TOY350]

Oh yeah... ABS light should come on to indicate disabled ABS like on my 98 right?

Yep.

 

[Boston Mangler]

Read this:

https://forum.ih8mud.com/showthread.php?t=44416&highlight=Diff+Lock+Dash+Light

 

[tucker74]

Couple of things you want to try - find somewhere off-road you can make long gradual arcs very slowly with the lockers engaged. That should help line up the dogs ... if still no luck get under there w/ a 9V and manually engage. You should be able to hear the motor ... if not you're gonna have to clean up the actuators. Search on the 9V method -

Good luck!

Tucker

 

[ace10]

i second the "give 'em a chance" suggestion by tucker.

 

[Godzilla FJ80]

Yeah, my truck did the same thing when I first got it. I was pretty bummed out about it. I'd shift into 4LOW and then turn the knob locking both diffs - blinking lights would never turn solid, even after moving forward for a second. Then one day I did the same thing, but this time I was in some soft grass, and I started turning the wheel back and forth as I inched forward. That did the trick, they both locked up. I can't tell you guys how happy I was about that. Now I make sure to lock'em up once a week or so. Interestingly enough, they lock up a lot quicker now that I'm using them.

 

[CruisinGA]

Maybe just coincidence, but my rear locker only started working after I changed the diff oil...

 

[mabrodis]

(I'm sure that link posted above addresses this, but I'll throw it in here also)

For the front/rear diff locks to work the center diff lock has to work AND fully lock (solid light on the dash, not just blinking). I have seen vehicles where the CDL was working, it WAS locking but the sensor was bad so it didn't think it was locked and therefore you could not lock the front/rear diff locks. Once the sensor was cleaned so the ECU recognized the CDL was actually locked, then it let the front/rear lockers attempt to engage, and surprisingly, both did without a problem. Most likely the very first time that vehicle had the lockers engaged. So make sure the CDL is locking and the ECU knows it's locked before worrying about the front/rear ones...

Good luck...care to share how much you bought the '93 with 243K miles for? (just curious..)

 

[jamot]

Mangler... Thanks for that thread. That is what I was looking for. Guess I shouldn't have used "damn lockers" in my key words search.

I also read Kumars post in the Slee tech section today, and feel pretty confident I'll diagnose it pretty quickly now. I have a day off and will do some tests in between some good ole 40 series patch panel fabbing....

Mabrodis... I picked this one up for $3k even. Brand new Michelins, only body defect is clearcoat is turning milky in areas on hood and a small "momma backed into the garage" dent in the plastic side bumper, soon to be replaced anyway. ARB winch bumper on her now with more work on getting her "in shape" ie, phh, more inspection etc.

I'm very surprised that at 243k there's not much drive train clunk. Much less than my 91 with 195k and no more than my 98-100 with 145k.

Price is a regional thing...... Down South these rigs don't have the same utilitarian value as in some areas of the country, and most rarely see any offroad use. Most of those rigs running around here with the factory diff locks weren't bought that way on purpose.

I do know of a 95 or 96 with factory diff locks and about 210k on it that can be had for about $6.5 or $6k. I know it has upgraded discs and I rebuilt the front knuckles/axle for the owner. PM me if anybody is interested and I should be able to put you in touch.

Thanks for all the help guys. The diff lock switch/sensor is suspect, but I'll update my findings in hopes of helping someone else.

 

[jamot]

A quick update to end this one... Mission Accomplished!

I tested the suspect front diff lock switch and it was not working. I removed it, hit it with a 20lb sledge a few times, crossthreaded it back in the t case and all is well!

Seriously though.... I removed the front diff lock switch, test jumped the terminals to verify switch wasn't working, then poked the switch a few times (literally) and reinstalled. I then "messaged" the t-case linkage (it was very stiff from lack of use) and now everything works beautifully. Both lockers lock and unlock with ease and speed.

I honestly think it was the first time the vehicle had been shifted to 4 low and the lockers activated. Wow!

Now on to a manual center diff lock switch and 7 pin mod.

Many thanks for the input fellas!