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Rubicon Locker Lights Flashing When Lockers Are Engaged

Jerry Bransford

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Ok thanks. I’m sure it isn’t regeared. It’s bone stock with right at 50k miles. I lifted it on jack stands and verified the lockers engage(all tires spin foward) Thought maybe the diff sensors were bad. I tried Jerry’s solution but was on pavement. I’m not sure if that matters.
Don't turn both lockers on when you're on the pavement. Once both are locked you may find the Jeep is bound up and can barely move. Lockers should only be engaged when you're on an offroad surface, not on pavement. Also, they don't lock immediately, they have to have some rotational difference between the L/R sides before they'll lock as described in post #13 above.

The locker light will flash until the lockers are properly engaged at which time it will turn solid. You also have to be in 4Lo before the lockers can be engaged.
 

TyJ

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Ok thank you. I will definitely give that a try. If the lockers were partially engaged would all 4 tires still spin in the same direction?
 

Nilgai

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Have you tried driving around doing s-turns? Rubicon and similar selectable lockers will not lock and the lights will continue flashing until you have made enough turns so they can lock. They will seldom lock just driving straight and they will never lock when sitting still.
I have a similar issue, but opposite! i just had my rubi re-geared to 4.88 and the rear locker light on dash flashes when i hit the brakes then goes out. Twice i got in the jeep and the light was just flashing with no key which is normal if you shut it off with the lockers engaged but they are not engaged and it is not in 4wd? Thoughts?
 
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Mike_H

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I have a similar issue, but opposite! i just had my rubi re-geared to 4.88 and the rear locker light on dash flashes when i hit the brakes then goes out. Twice i got in the jeep and the light was just flashing with no key which is normal if you shut it off with the lockers engaged but they are not engaged and it is not in 4wd? Thoughts?
Sounds like the gear install shop might not have know to set the sensor properly when they re-installed the gears. I'm not familiar enough with the proceedure to describe it, but @Jerry Bransford can direct you to a post where it is described.
 

AndyG

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Sounds like the gear install shop might not have know to set the sensor properly when they re-installed the gears. I'm not familiar enough with the proceedure to describe it, but @Jerry Bransford can direct you to a post where it is described.
Mike is 100% right and that is exactly what you have happening.

they're going to have to go back into it remove the carrier and set the sensor correctly so that it catches on the locker when the carrier is reinstalled.

Don't fool around with it... Get it fixed you can ruin a locker by driving with a partially engaged .. or it can throw it into an engaged position at the wrong time.
 
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mrblaine

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Ok thank you. I will definitely give that a try. If the lockers were partially engaged would all 4 tires still spin in the same direction?
Not sure why in all of this there isn't an actual test to check if they are in fact locked. Only jack up one tire, if you only have one floor jack, put a jack stand under one side in the back, move the floor jack to the front and lift up one side.

Put it in 4 low, lock the rear, get out and turn the tire by hand until it locks or you know that it isn't going to. Once it is locked and unable to be turned, check the light. Lock the front, turn the tire until it locks or doesn't. If it does, check the light. That will tell if the lockers, switch, and lights are all working as they should.
 

Jerry Bransford

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I have a similar issue, but opposite! i just had my rubi re-geared to 4.88 and the rear locker light on dash flashes when i hit the brakes then goes out. Twice i got in the jeep and the light was just flashing with no key which is normal if you shut it off with the lockers engaged but they are not engaged and it is not in 4wd? Thoughts?
There's a locker position sensor in the axle housing and if the gearing shop doesn't know how to properly install the carrier to properly engage that sensor problems will develop. One is that the locker will be forced into a partially engaged position even when the locker is not locked, even when you're in 2wd. Two the sensor will indicate the locker is locked all the time, when it is not, which will cause the locker lights to flash, warning of a problem.

Here are a few pics I made during my regear and one illustration I found when I had a similar problem after my first axle regearing was completed. We were stymied for a day or two until research pointed at the locker actuator sensor.

The locker sensor sensor is at the top here shown in its correct position. When the locker actuator engages it pulls the sensor tip toward the left indicating the locker is engaged. Its mushroom shaped tip must be positioned on the 'other' side of the actuator plate so this can happen.

81263


This shows the sensor in the top center of the photo. That funny red thing stuck in it is a short piece of wooden toothpick. Its temporary job is to hold the sensor out fully until it can be released after the carrier has been installed. Attached to it is a short length of fishing line so the toothpick can be removed once the carrier is properly positioned.

81261
81262


This shows the actuator plate at the very top of the carrier. There's an air bladder inside it that when inflated pushes against the locker to lock it. The sensor detects the position of this actuator plate. The "ears" that normally stick up at a 90 degree photo have been temporarily bent down during the bearing removal process.

81264
 
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AndyG

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Not sure why in all of this there isn't an actual test to check if they are in fact locked. Only jack up one tire, if you only have one floor jack, put a jack stand under one side in the back, move the floor jack to the front and lift up one side.

Put it in 4 low, lock the rear, get out and turn the tire by hand until it locks or you know that it isn't going to. Once it is locked and unable to be turned, check the light. Lock the front, turn the tire until it locks or doesn't. If it does, check the light. That will tell if the lockers, switch, and lights are all working as they should.
I'll tell you why in my case it wasn't suggested... Man I can't hold a candle to you in terms of depth and breadth of knowledge about these things.

I have read post that you have put on here on the various subjects and have been absolutely astounded... I'm like ...is there anything this guy doesn't understand inside and out about these vehicles?

I'm not blowing Sunshine up your rear end... Your presence here is appreciated and respected.

I have strived to excel in my chosen field.. and I can instantly recognize someone who is doing the same thing and has succeeded at that

Stay with us.

I have also seen post on here for some poor fella is trying to get a TJ straightened out and some shop is trying to put two stabilizers on it..

guys like you and Jerry and Chris calling bull on things like that is absolutely a huge help to people.
 

mrblaine

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I'll tell you why in my case it wasn't suggested... Man I can't hold a candle to you in terms of depth and breadth of knowledge about these things.

I have read post that you have put on here on the various subjects and have been absolutely astounded... I'm like ...is there anything this guy doesn't understand inside and out about these vehicles?

I'm not blowing Sunshine up your rear end... Your presence here is appreciated and respected.

I have strived to excel in my chosen field.. and I can instantly recognize someone who is doing the same thing and has succeeded at that

Stay with us.

I have also seen post on here for some poor fella is trying to get a TJ straightened out and some shop is trying to put two stabilizers on it..

guys like you and Jerry and Chris calling bull on things like that is absolutely a huge help to people.
It wasn't pointed at a specific anyone, it was the age of the thread almost 2 years old and no diagnostics. Nothing more.
 

AndyG

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It wasn't pointed at a specific anyone, it was the age of the thread almost 2 years old and no diagnostics. Nothing more.
No offense taken it all... That was all meant as a compliment and it was a clear illustration of your ability to get to the heart of a problem quickly.
 

AndyG

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My response was for the post made 2:13am PST this morning. :)
Hey Jerry I've got one for you...

Remember the post the other night where we shouldn't re-gear?

You know why you never argue with an idiot? Because they will drag you down to their level and then beat you with experience.

😁
 
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Nilgai

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There's a locker position sensor in the axle housing and if the gearing shop doesn't know how to properly install the carrier to properly engage that sensor problems will develop. One is that the locker will be forced into a partially engaged position even when the locker is not locked, even when you're in 2wd. Two the sensor will indicate the locker is locked all the time, when it is not, which will cause the locker lights to flash, warning of a problem.

Here are a few pics I made during my regear and one illustration I found when I had a similar problem after my first axle regearing was completed. We were stymied for a day or two until research pointed at the locker actuator sensor.

The locker sensor sensor is at the top here shown in its correct position. When the locker actuator engages it pulls the sensor tip toward the left indicating the locker is engaged. Its mushroom shaped tip must be positioned on the 'other' side of the actuator plate so this can happen.

View attachment 81263

This shows the sensor in the top center of the photo. That funny red thing stuck in it is a short piece of wooden toothpick. Its temporary job is to hold the sensor out fully until it can be released after the carrier has been installed. Attached to it is a short length of fishing line so the toothpick can be removed once the carrier is properly positioned.

View attachment 81261View attachment 81262

This shows the actuator plate at the very top of the carrier. There's an air bladder inside it that when inflated pushes against the locker to lock it. The sensor detects the position of this actuator plate. The "ears" that normally stick up at a 90 degree photo have been temporarily bent down during the bearing removal process.

View attachment 81264
Thanks so much for this. the guys keeps telling me he pulled the sensor out and has reinstalled it correctly when in fact per this ilistration he has to pull the carrier to get it in position. UGH! Jeep jamboree this weekend and time is running out!!
 

Nilgai

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San Antonio, Texas, USA
There's a locker position sensor in the axle housing and if the gearing shop doesn't know how to properly install the carrier to properly engage that sensor problems will develop. One is that the locker will be forced into a partially engaged position even when the locker is not locked, even when you're in 2wd. Two the sensor will indicate the locker is locked all the time, when it is not, which will cause the locker lights to flash, warning of a problem.

Here are a few pics I made during my regear and one illustration I found when I had a similar problem after my first axle regearing was completed. We were stymied for a day or two until research pointed at the locker actuator sensor.

The locker sensor sensor is at the top here shown in its correct position. When the locker actuator engages it pulls the sensor tip toward the left indicating the locker is engaged. Its mushroom shaped tip must be positioned on the 'other' side of the actuator plate so this can happen.

View attachment 81263

This shows the sensor in the top center of the photo. That funny red thing stuck in it is a short piece of wooden toothpick. Its temporary job is to hold the sensor out fully until it can be released after the carrier has been installed. Attached to it is a short length of fishing line so the toothpick can be removed once the carrier is properly positioned.

View attachment 81261View attachment 81262

This shows the actuator plate at the very top of the carrier. There's an air bladder inside it that when inflated pushes against the locker to lock it. The sensor detects the position of this actuator plate. The "ears" that normally stick up at a 90 degree photo have been temporarily bent down during the bearing removal process.

View attachment 81264
Also, he lockers lock and the light stays solid. it just when braking the light flashes when unlocked? Are we still talking the same language here? Just rear locker flashes.
 

Nilgai

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Messages
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Location
San Antonio, Texas, USA
There's a locker position sensor in the axle housing and if the gearing shop doesn't know how to properly install the carrier to properly engage that sensor problems will develop. One is that the locker will be forced into a partially engaged position even when the locker is not locked, even when you're in 2wd. Two the sensor will indicate the locker is locked all the time, when it is not, which will cause the locker lights to flash, warning of a problem.

Here are a few pics I made during my regear and one illustration I found when I had a similar problem after my first axle regearing was completed. We were stymied for a day or two until research pointed at the locker actuator sensor.

The locker sensor sensor is at the top here shown in its correct position. When the locker actuator engages it pulls the sensor tip toward the left indicating the locker is engaged. Its mushroom shaped tip must be positioned on the 'other' side of the actuator plate so this can happen.

View attachment 81263

This shows the sensor in the top center of the photo. That funny red thing stuck in it is a short piece of wooden toothpick. Its temporary job is to hold the sensor out fully until it can be released after the carrier has been installed. Attached to it is a short length of fishing line so the toothpick can be removed once the carrier is properly positioned.

View attachment 81261View attachment 81262

This shows the actuator plate at the very top of the carrier. There's an air bladder inside it that when inflated pushes against the locker to lock it. The sensor detects the position of this actuator plate. The "ears" that normally stick up at a 90 degree photo have been temporarily bent down during the bearing removal process.

View attachment 81264
Jerry in your illustration are you sure it pulls to the left or do you mean it pulls mushroom head to the right when engaged? Im learning here, bear with me.!:)
 

AndyG

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If he did not pull the carrier he does not have the sensor pin in correctly... It's basically impossible.