[Dakota65]

I tried engaging the Rear Diff the other day and the indicator light just kept blinking. I tried switching it on and off, forward and reverse, swerving back and forth and it didn't change. What is my next step?

 

[Effief100]

Drive slowly forward and turn left and right. It doesn’t take much left and right to lock up. It should lock up then. It’s what I have to do most of the time.

 

[Dakota65]

I tried that several times on a gravel road and no luck.

 

[Winterpeg]

Were you in 4Lo and driving slowly forward or backwards?

 

[Dakota65]

Yes 4 Low forward, backward, swerved back and forth, fast and slow, atrac on and off.

 

[Winterpeg]

Try jacking it up and putting it on jackstands on all 4 corners.... and try locking it with all tires off the ground.

I've had that work once.... I think I turned the wheels by hand while in neutral.

Once you do get it going, keep using it to keep it lubed.

 

[gkreitzburg]

Jack the rear wheels off the ground and climb under and smack the locker housing lightly while someone moves the wheels back and forth.

Then, as @Winterpeg said lock and unlock occasionally. I had this happen last month while i was off-road; as I hadn't locked it in quite some time. Now i lock it occasionally when off-road; just to keep it lubed.

 

[ottor5191]

If you don't use it, it can seize.

 

[Lee44]

Perhaps it is locked but has a sensor issue. On the dirt make a fairly tight turn either way and check your rear tire tracks. The inside wheel will tear up the dirt if rear end is locked. There is a way to test by lifting both rear wheels off the ground but I've never done that.

Like others, when I'm off road I run in both 4HI and 4LO to lubricate gears in the transfer case. In 4LO I also engage and disengage the rear diff lock several times. (4WD - Auto)

 

[Dakota65]

If you don't use it, it can seize.

Learned that the hard way with my JK Rubicon. This FJ is new to me.

 

[sjalabs]

I tried engaging the Rear Diff the other day and the indicator light just kept blinking. I tried switching it on and off, forward and reverse, swerving back and forth and it didn't change. What is my next step?

You must be in 4L (part time) or LL (Full time system) in order to lock the rear diff. The flashing diff lock light indicates 1 of 2 things depending on my previous statement, either you are not in low range and or the lock is working to engage. Sometime you need to get the wheels moving (very slowly!!!!!) to get the diff lock to engage as the splines need time to line up inside the diff, doesn’t matter if your already stuck in the mud as its really just the internal diff gears that have to move around to make things line up so very slow brief wheel spin is fine. Sometime it takes the coaksing as noted above and sometime it locks immediately. Other than that its a very reliable locker. Mine has been put through many workouts over the past 14 years and never failed.

I would also strongly recommend consulting the FJ owners manual as it very clearly states how to use the diff lock and A-TRAC, as well as all of the dos and don’ts.

 

[jmylie]

Read these:

rear differential

My locking rear differential wont work, light just flashes. I did all the rocking back and forth, turning 45 degree trick, gently gave it gas in neutral, drove in 4lo for while first shown on previous forums. I used it twice this fall and after getting completely stuck with it off and it...

www.fjcruiserforums.com

Installing a new rear differential lock actuator (Part 1)

I bought a 2007 FJ Cruiser with manual transmission last month. It has 138,000 miles. I purchased it knowing that the rear differential lock did not seem to be working. Here is a step-by-step description of the symptoms and how I fixed it. In normal driving with the transfer case in "H", no...

www.fjcruiserforums.com

I had to replace mine last month.

 

[Dakota65]

Should there be some clicking noises coming from the rear diff lock even if it is stuck? On my daughters FJ I can hear a click then when i roll forward and move the steering wheel i can hear the diff lock up. Also if it was a fuse would the dash light flash when the diff lock button was pushed?

 

[Iconic_]

On my daughters FJ I can hear a click then when i roll forward and move the steering wheel i can hear the diff lock up.

That is totally normal, that means it's working properly. If there is no click and no tire dragging then the diff lock actuator isn't engaging.

 

[CT_FJCruiser]

I replaced my actuator, and verified functionality, but still hd the light blinking. Apparently the lock sensor can go bad separately from the actuator, so the dash light is not necessarily an accurate indicator

 

[FJtest]

Aside from the three range-sensing plunger switches on the AT transfer case there is yet another one of these switches in the rear axle that senses when the diff lock actuator has mechanically locked the diff.

Make sure that your diff isn't actually locked ... jack up the rear end and verify that when you rotate one rear wheel the opposite wheel rotates in the same direction. If it does, then the diff IS locked, and it's possible that the position sensing switch isn't electrically closing and is failing to send the 4WD ECU the signal to indicate the diff is locked.

If the rear wheels rotate in opposite directions, then the diff is not locked, and you'll need to determine if the locker is getting the signal to lock, and if it is, if the locker is jammed, seized or otherwise non-functional.