Locker Position Sensor Potting - DANA 44

[DavidArmen]

After a week of diag the dealership has come to the conclusion that my Jeep has the wrong front axle in it. I was in an accident last July and the front axle was one of the many things that needed to be replaced. According to the dealership here in PA, the dealership in Norfolk that did the work put in an axle for a 2023+ Rubicon and it doesn't know how to properly communicate with my 2021 Rubicon. I can't say for certain but this might be why my lockers still functioned properly even with the Service Axle Locker warning active.

Anyway, I'm probably just going to throw a Z Locker harness at it rather than fight with the insurance company and an incompetent dealership to get another axle under it

This is a possible piece of evidence that even if the new sensor and solenoid kit were able to be installed onto 2022 and older Rubicon axles, and even if they operated the lockers, there will still be dash lights for the lockers because of the presumed lack of complete collaboration between the sensor and the Jeep computer.

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[roaniecowpony]

This is a possible piece of evidence that even if the new sensor and solenoid kit were able to be installed onto 2022 and older Rubicon axles, and even if they operated the lockers, there will still be dash lights for the lockers because of the presumed lack of complete collaboration between the sensor and the Jeep computer.

If those parts were actually available, it might matter. So far, I haven't been able to purchase any part of the differential carrier or locker for a Rubicon. YMMV.

 

[roaniecowpony]

Those of you having actuation problems, I recommend you get out a multimeter and check the power and ground to the axle on the factory chassis harness.

There are also two signal wires. I haven't found the OE voltage values for them. But my guess is that one is the Hall sensor voltage feed and the other is a return to the module and the module measures voltage change from the hall effect sensor.

 

[Terrymo]

@chevymitchell @roaniecowpony etc
What variables can occur that require all 5 locker position sensors in the kit. I have a hard time believing whoever is originally assembling these axles is hand fitting and swapping the sensors to find out which one works on the rear locker and which one works on the front locker. Seems like there would be something that could be measured by a multimeter to make that decision.

 

[chevymitchell]

@chevymitchell @roaniecowpony etc
What variables can occur that require all 5 locker position sensors in the kit. I have a hard time believing whoever is originally assembling these axles is hand fitting and swapping the sensors to find out which one works on the rear locker and which one works on the front locker. Seems like there would be something that could be measured by a multimeter to make that decision.

It’s likely there was several tolerance values depending on the part # or dash # of the BCM or the difference in tolerances for the sensors in the BCM firmware versions. It’s easier to send out a pack of cheap sensors instead of asking people to come to the dealer to collect that info and then order what they need.

We wouldn’t be able to know the tolerance values built into the firmware of the BCM without the ICD or a scope setup where you could inject a signal to find the high and low side of where the error was.

It’s a lot of work and setup time to figure it out. Much easier to just plug a sensor in and see if the light goes out. That’s what the MFG would hope for their customers.

 

[Terrymo]

It’s likely there was several tolerance values depending on the part # or dash # of the BCM or the difference in tolerances for the sensors in the BCM firmware versions. It’s easier to send out a pack of cheap sensors instead of asking people to come to the dealer to collect that info and then order what they need.

We wouldn’t be able to know the tolerance values built into the firmware of the BCM without the ICD or a scope setup where you could inject a signal to find the high and low side of where the error was.

It’s a lot of work and setup time to figure it out. Much easier to just plug a sensor in and see if the light goes out. That’s what the MFG would hope for their customers.

Got it. Thank you. I have to read the manual to use some functions in my multimeter so this is all above my pay grade. Trial and error works.

 

[roaniecowpony]

@chevymitchell @roaniecowpony etc
What variables can occur that require all 5 locker position sensors in the kit. I have a hard time believing whoever is originally assembling these axles is hand fitting and swapping the sensors to find out which one works on the rear locker and which one works on the front locker. Seems like there would be something that could be measured by a multimeter to make that decision.

Since a Hall effect generates a small voltage, depending on relative position of the magnet, my guess would be that the mechanical tolerances (variations in dimensions) between the locked and unlocked position of the sensor target (on the actuator plate) relative to the sensor (on the actuator coil) will create different voltages (very small voltage variations) which were probably originally calibrated in the locker module on the production line for the locked and unlocked position. I can't imagine that they are trying different sensors on the production line. They probably just plug in the axle and command the locker on a test console, then burn the voltages for the two positions into the NVM.

 

[Terrymo]

Since a Hall effect generates a small voltage, depending on relative position of the magnet, my guess would be that the mechanical tolerances (variations in dimensions) between the locked and unlocked position of the sensor target (on the actuator plate) relative to the sensor (on the actuator coil) will create different voltages (very small voltage variations) which were probably originally calibrated in the locker module on the production line for the locked and unlocked position. I can't imagine that they are trying different sensors on the production line. They probably just plug in the axle and command the locker on a test console, then burn the voltages for the two positions into the NVM.

Thanks

 

[Terrymo]

@Astro Jeep any progess on yours? If my locker position sensor kit arrives today, I will be doing this project this weekend.

 

[Astro Jeep]

@Astro Jeep any progess on yours? If my locker position sensor kit arrives today, I will be doing this project this weekend.

@Terrymo Long story short... I ruined two of the original five I potted when drilling the holes. One of those two was the one I needed for my rear axle. How do I know? I know by the way the dashlights responded. I ordered another kit and more potting epoxy, which arrived on Tuesday. This time, I am going to install them un-potted. Identify which ones I need, and THEN pot them and re-install them. I potted first the last time to save time, but it cost me more money. I will use my smallest drill bit to make an initial pilot hole this time. Then, I will take the proper-sized drill and, using a tap holder, enlarge the hole to size by hand. I hope that by doing it this way, I won't accidentally plunge into the circuit board again. Just my luck that I ruined the one I needed.

 

[CenTX JPR]

@Astro Jeep - I used a rivet as a depth stop while drilling. Post #156 in this thread.

https://www.jlwranglerforums.com/fo...ion-sensor-potting-dana-44.59581/post-1406002

 

[swampflyer]

I understand all this and would-say just get a arb or eaten and screw it. This has got to be the biggest jug fuck I’ve ever seen. lol

 

[BRuby]

@Terrymo Long story short... I ruined two of the original five I potted when drilling the holes. One of those two was the one I needed for my rear axle. How do I know? I know by the way the dashlights responded. I ordered another kit and more potting epoxy, which arrived on Tuesday. This time, I am going to install them un-potted. Identify which ones I need, and THEN pot them and re-install them. I potted first the last time to save time, but it cost me more money. I will use my smallest drill bit to make an initial pilot hole this time. Then, I will take the proper-sized drill and, using a tap holder, enlarge the hole to size by hand. I hope that by doing it this way, I won't accidentally plunge into the circuit board again. Just my luck that I ruined the one I needed.

Very very unfortunate to hear that a couple of your locker sensors were ruined.

If you have access to a handheld adjustable speed drill that has a sliding metal rod guide attached to the drill body - you can manually control the drill depth to "micro fractions of an inch". As without the guide the risk level to accidentally hit the PCB is exponentially higher.

I also have a hand drill. But using that - found the risk level was way too high to hand hold without a brace. Also did not drill a pilot hole. Just make sure your bit is sharp and cuts clean and easy.

I did document the entire sensor removal - including my drilling and potting procedure with high res photos and 4K video. Here are a few screen grabs showing how the metal rod guide is simply positioned against the vise and then held in position by my fingers. This allows you to position the drill bit to "engage the plastic" with complete precision.

Just apply gentle pivot pressure and work your way down - the same as a fixed drill press. The difference is that you can control the drill speed to "just pierce the bottom of the hole" before stopping. Then use a steel pick to gently push the remaining plastic flap down and into the cavity. This ensures there is zero risk the PCB can be damaged by the drill bit hitting it.

I tried to remove the super thin plastic flap at first - but decided to not risk it. So just pushed the flap in. Hopefully you can get your other sensors to drill ok. As the drilling can be risky. Possibly others attempting this will be able to avoid this issue now with all the member feedback.

As a side note. Before potting my lockers would take about 2 sec to engage or disengage. After draining the oil and cleaning and potting - lockers engage and disengage "as soon as" the dash lever is moved up or down or is turned off. So basically immediately. Luckily my locker sensors had not been submerged in oil to where metal particulates created a short.

Also I was able to see that the translucent top was letting oil in as well. Since after potting was able to see potting material bulge out the sides - where it attached to the black housing. So for sure these sensor lockers will fail in time unless potted. Mine is 6 years old and is still ok. Pure luck.

 

[Astro Jeep]

Very very unfortunate to hear that a couple of your locker sensors were ruined.

If you have access to a handheld adjustable speed drill that has a sliding metal rod guide attached to the drill body - you can manually control the drill depth to "micro fractions of an inch". As without the guide the risk level to accidentally hit the PCB is exponentially higher.

I also have a hand drill. But using that - found the risk level was way too high to hand hold without a brace. Also did not drill a pilot hole. Just make sure your bit is sharp and cuts clean and easy.

I did document the entire sensor removal - including my drilling and potting procedure with high res photos and 4K video. Here are a few screen grabs showing how the metal rod guide is simply positioned against the vise and then held in position by my fingers. This allows you to position the drill bit to "engage the plastic" with complete precision.

Just apply gentle pivot pressure and work your way down - the same as a fixed drill press. The difference is that you can control the drill speed to "just pierce the bottom of the hole" before stopping. Then use a steel pick to gently push the remaining plastic flap down and into the cavity. This ensures there is zero risk the PCB can be damaged by the drill bit hitting it.

I tried to remove the super thin plastic flap at first - but decided to not risk it. So just pushed the flap in. Hopefully you can get your other sensors to drill ok. As the drilling can be risky. Possibly others attempting this will be able to avoid this issue now with all the member feedback.

As a side note. Before potting my lockers would take about 2 sec to engage or disengage. After draining the oil and cleaning and potting - lockers engage and disengage "as soon as" the dash lever is moved up or down or is turned off. So basically immediately. Luckily my locker sensors had not been submerged in oil to where metal particulates created a short.

Also I was able to see that the translucent top was letting oil in as well. Since after potting was able to see potting material bulge out the sides - where it attached to the black housing. So for sure these sensor lockers will fail in time unless potted. Mine is 6 years old and is still ok. Pure luck.

Thank you for the suggestions. It looks like good advice to me.

 

[Astro Jeep]

I understand all this and would-say just get a arb or eaten and screw it. This has got to be the biggest jug fuck I’ve ever seen. lol

I agree, and I almost went that route. It is a rabbit hole because the Rubicon splines are 32, and the ARB for Rubicon requires a 35 spline, so you need new shafts. If you need new ones, you might as well go with Chromoly. I have the ARB air compressor, but I would need a manifold and a tank if I went with the air locker. If you are going to pull all that, you might as well get everything else new since there is 100k on the Jeep. Pretty soon, you realize those D60s you want to buy in two years won't happen if you pour all this money into the D44. Hence fixing what I have.

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