VKSheridan

Well-Known Member
First Name
Vince
Joined
Dec 21, 2019
Messages
95
Reaction score
139
Location
Broken Arrow, OK
Vehicle(s)
2020 2 Dr Rubicon JL Hardtop
First and foremost, thank you for your military service. I totally understand the principles and usage of potting and yes, it’s nothing new.

Discussions in a forum can be difficult and I fear you’re missing my point. Read what you wrote…..

The only way you can pot too late is if your rig is already showing a locker fault. Then the whole idea is moot.
What I am saying is you can try to reflow (bake) the PCB before you conclude it junk. If continuity is lost or near lost due to an inadequate solder soak at time of manufacture, adding potting is unlikely to restore it.

Potting a sensor in advance *might* hold the components in place but it might not help if the component arc opens in its potted mount.

Opinion: I think the reason FCA wants to swap the whole axle is to increase the costs to Dana to make it unaffordable for them to restrict the sale of the sensors. Dana doesn’t want to sell the sensors? Fine, eat the cost of a bunch of axles……
Advertisement

 

chevymitchell

Well-Known Member
First Name
Shawn
Joined
Feb 18, 2018
Messages
2,004
Reaction score
4,055
Location
K-Vegas, NC
Vehicle(s)
2019 JLUR (Pain Train)
Occupation
Super Nerd
First and foremost, thank you for your military service. I totally understand the principles and usage of potting and yes, it’s nothing new.

Discussions in a forum can be difficult and I fear you’re missing my point. Read what you wrote…..



What I am saying is you can try to reflow (bake) the PCB before you conclude it junk. If continuity is lost or near lost due to an inadequate solder soak at time of manufacture, adding potting is unlikely to restore it.

Potting a sensor in advance *might* hold the components in place but it might not help if the component arc opens in its potted mount.

Opinion: I think the reason FCA wants to swap the whole axle is to increase the costs to Dana to make it unaffordable for them to restrict the sale of the sensors. Dana doesn’t want to sell the sensors? Fine, eat the cost of a bunch of axles……
I think you're misunderstanding what's happening when the sensors fail. It's not cold/cracked joints.

They're failing because the gear oil has metal flake in it which is shorting out 1 of the 3 capacitors on the board. The potting material is just keeping the gear oil from getting to the PCB.

Nothing more than that.
 

Dyolfknip74

Well-Known Member
Joined
Mar 18, 2021
Messages
706
Reaction score
766
Location
Ottawa, Ontario, Canada
Vehicle(s)
2021 JLU Rubicon
First and foremost, thank you for your military service. I totally understand the principles and usage of potting and yes, it’s nothing new.

Discussions in a forum can be difficult and I fear you’re missing my point. Read what you wrote…..



What I am saying is you can try to reflow (bake) the PCB before you conclude it junk. If continuity is lost or near lost due to an inadequate solder soak at time of manufacture, adding potting is unlikely to restore it.

Potting a sensor in advance *might* hold the components in place but it might not help if the component arc opens in its potted mount.

Opinion: I think the reason FCA wants to swap the whole axle is to increase the costs to Dana to make it unaffordable for them to restrict the sale of the sensors. Dana doesn’t want to sell the sensors? Fine, eat the cost of a bunch of axles……
Lol, thank you. It was actually closer to a 30 years career, but I figured I would give the infantry a solid dozen years before I really knew what I wanted to do in the army, lol.

Tough to bake these PCBs though, the housing is destroyed if you try to pull out PCB.

Notwithstanding, I think @chevymitchell hit the nail on the head as to the cause of the failures.

Good discussion though, thank you.
 

VKSheridan

Well-Known Member
First Name
Vince
Joined
Dec 21, 2019
Messages
95
Reaction score
139
Location
Broken Arrow, OK
Vehicle(s)
2020 2 Dr Rubicon JL Hardtop
I think you're misunderstanding what's happening when the sensors fail. It's not cold/cracked joints.

They're failing because the gear oil has metal flake in it which is shorting out 1 of the 3 capacitors on the board. The potting material is just keeping the gear oil from getting to the PCB.

Nothing more than that.
While it’s plausible microscoptic metal particles can migrate into openings in the sensor and short components, that is merely speculation used to affirm a preconceived failure mode. Arc surging a capacitor can create the same result.

Again, I don’t care if you guys want to pot everything on your ride, I’m just saying there is more than one way to fail a sensor and being oil soaked is not usually the primary failure mode.
 

chevymitchell

Well-Known Member
First Name
Shawn
Joined
Feb 18, 2018
Messages
2,004
Reaction score
4,055
Location
K-Vegas, NC
Vehicle(s)
2019 JLUR (Pain Train)
Occupation
Super Nerd
While it’s plausible microscoptic metal particles can migrate into openings in the sensor and short components, that is merely speculation used to affirm a preconceived failure mode. Arc surging a capacitor can create the same result.

Again, I don’t care if you guys want to pot everything on your ride, I’m just saying there is more than one way to fail a sensor and being oil soaked is not usually the primary failure mode.
Arc surge is not the cause for our particular issue on these axles and oil getting into the sensor is the primary failure mode. Of course, there's more than one way the sensor could fail. I could hit it with a hammer. It's easy not to speculate when every reported sensor that's failed is due to oil contamination. Those sensors without oil have not failed yet. This could easily be proven if I could get my hands on a couple of good sensors no one is using.

Are you going to pot yours?
 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Messages
4,503
Reaction score
5,895
Location
Hurricane, UT
Vehicle(s)
2018 JLUR, 2020 Acura RDX A-Spec
Occupation
I make microchips for a living.
Vehicle Showcase
1
I’ve read the posts and yes, a dude used RTV. I can see how one might credit potting as the cure if they‘ve had no incidents after gluing a perfectly good board in place but is that the true cure or a miscredit? Not too sure.

There are several stories of “I potted it too late” which assumes the PCB components failed and not how they’re attached to the PCB. Once you pot it, baking the board becomes that much less likely to fix it.

I’m not trying to convince anyone they’re wrong, I’m just saying I’ve seen far more PCB’s fail from thermal/vibration micro-fractures then from being exposed to oil and other root causes could exist. If you want to resin your sensors, go for it, hope you get lucky.
We've been dealing with this issue on a different thread(s) for 3 years now and it is definitely oil in the sensor and not bad solder joints. People have documented extensively what they are seeing and @chevymitchell came up with a potting thread using potting compound, not rtv.
Regardless of how the oil is getting in there (mine came in from a separated seal others say through the wire connector) many people have confirmed there is oil in the sensor. To date I'm the only one who was lucky enough to actually pop the lid off, drain the oil, clean it out and re-seal it to become a working sensor. Others have gone the potting route before oil has entered the sensor and have had good results.
 

DanW

Well-Known Member
First Name
Dan
Joined
Mar 2, 2017
Messages
7,730
Reaction score
9,861
Location
Indiana
Vehicle(s)
18 JLUR, 08 JKUR, 15 Ford Transit 350, 04 WJ 4.7, 17 Renegade, 99 Merc E430 S
Vehicle Showcase
2
I'll have to check in with my friend at Stellantis to see if he's heard back from the powertrain group on a solution to this, or not. I told him our hope is to offer new sensors at the parts counter to avoid junking the whole axle and to have an easy/cheap fix after the warranty is up.

I wonder, though, if Stellantis' solution will be new sensors with better QC in production units just to fix the warranty cost side of it, leaving those out of warranty out of luck.

I fear there's not enough failures to make a business case for the aftermarket to supply these. That would be another solution I'd love to see.
 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Messages
4,503
Reaction score
5,895
Location
Hurricane, UT
Vehicle(s)
2018 JLUR, 2020 Acura RDX A-Spec
Occupation
I make microchips for a living.
Vehicle Showcase
1
I'll have to check in with my friend at Stalin to see if he's heard back from the powertrain group on a solution to this, or not. I told him our hope is to offer new sensors at the parts counter to avoid junking the whole axle and to have an easy/cheap fix after the warranty is up.

I wonder, though, if Stalin's solution will be new sensors with better QC in production units just to fix the warranty cost side of it, leaving those out of warranty out of luck.

I fear there's not enough failures to make a business case for the aftermarket to supply these. That would be another solution I'd love to see.
I fixed your post.
 

VKSheridan

Well-Known Member
First Name
Vince
Joined
Dec 21, 2019
Messages
95
Reaction score
139
Location
Broken Arrow, OK
Vehicle(s)
2020 2 Dr Rubicon JL Hardtop
Arc surge is not the cause for our particular issue on these axles and oil getting into the sensor is the primary failure mode. Of course, there's more than one way the sensor could fail. I could hit it with a hammer. It's easy not to speculate when every reported sensor that's failed is due to oil contamination. Those sensors without oil have not failed yet. This could easily be proven if I could get my hands on a couple of good sensors no one is using.

Are you going to pot yours?
I love the conversation but please - It is a tad disingenuous to say EVERY reported sensor failure has been diagnosed, let alone diagnosed as oil ingression on the PCB. Some guys saw the light come on, took it to the dealer and got the axle replaced. Sometimes twice. Inference to any given root cause is speculative at best.

None the matter, we’ve beat the flies off this dead pony.

I’m hoping to maybe snag a pair of sensors from a wrecked Jeep at the Pick a Part and pot them for replacement upon failure. I figure if I can get a pair of non-failed units, confirm they can be permanently sealed with all bases covered, they should last until a lightning strike, gear blow out or I throw them away. Heck, maybe (just maybe) Dana will wise up and find a different source of supply……

Have a great Thanksgiving!
 

Dyolfknip74

Well-Known Member
Joined
Mar 18, 2021
Messages
706
Reaction score
766
Location
Ottawa, Ontario, Canada
Vehicle(s)
2021 JLU Rubicon
I love the conversation but please - It is a tad disingenuous to say EVERY reported sensor failure has been diagnosed, let alone diagnosed as oil ingression on the PCB. Some guys saw the light come on, took it to the dealer and got the axle replaced. Sometimes twice. Inference to any given root cause is speculative at best.

None the matter, we’ve beat the flies off this dead pony.

I’m hoping to maybe snag a pair of sensors from a wrecked Jeep at the Pick a Part and pot them for replacement upon failure. I figure if I can get a pair of non-failed units, confirm they can be permanently sealed with all bases covered, they should last until a lightning strike, gear blow out or I throw them away. Heck, maybe (just maybe) Dana will wise up and find a different source of supply……

Have a great Thanksgiving!
I think we may be hard pressed to get sensors like that. I cant see any junk dealer letting someone cannibalize a D44 axle just for the sensor when they can sell the complete unit and make a lot more money.
In saying that, if you do find one, do it and RUN. lol
 

GATORB8

Well-Known Member
First Name
Matt
Joined
May 30, 2021
Messages
1,768
Reaction score
1,974
Location
CLT NC
Vehicle(s)
21 JLUR 4xe
I think we may be hard pressed to get sensors like that. I cant see any junk dealer letting someone cannibalize a D44 axle just for the sensor when they can sell the complete unit and make a lot more money.
In saying that, if you do find one, do it and RUN. lol
Would the same sensor be in the Bronco or something else? That’s the same pumpkin just no tubes, right?
 

Dyolfknip74

Well-Known Member
Joined
Mar 18, 2021
Messages
706
Reaction score
766
Location
Ottawa, Ontario, Canada
Vehicle(s)
2021 JLU Rubicon
Would the same sensor be in the Bronco or something else? That’s the same pumpkin just no tubes, right?
Not sure of what other Dana applications may be using. It's a new axle for the JL, the JK used a mechanical switch if I remember correctly.

Who makes the Bronco axle? Pretty sure it isn't Dana. From a spec sheet I found:

"Front: Independent H.O.S.S. (High-Performance, Off-Road, Stability, Suspension) System with twin alloy A-arms and coil-over springs for optimum off-road stability and control with available H.O.S.S. System with Bilstein® Position Sensitive Dampers. Rear: Solid five-link rear axle H.O.S.S. (High-Performance, Off-Road, Stability, Suspension) System with coil-over springs for optimum off-road capability and durability with available H.O.S.S. System with Bilstein Position Sensitive Dampers."
 

GATORB8

Well-Known Member
First Name
Matt
Joined
May 30, 2021
Messages
1,768
Reaction score
1,974
Location
CLT NC
Vehicle(s)
21 JLUR 4xe
Not sure of what other Dana applications may be using. It's a new axle for the JL, the JK used a mechanical switch if I remember correctly.

Who makes the Bronco axle? Pretty sure it isn't Dana. From a spec sheet I found:

"Front: Independent H.O.S.S. (High-Performance, Off-Road, Stability, Suspension) System with twin alloy A-arms and coil-over springs for optimum off-road stability and control with available H.O.S.S. System with Bilstein® Position Sensitive Dampers. Rear: Solid five-link rear axle H.O.S.S. (High-Performance, Off-Road, Stability, Suspension) System with coil-over springs for optimum off-road capability and durability with available H.O.S.S. System with Bilstein Position Sensitive Dampers."
It’s a Dana in the new Bronco, advantek, not sure which ones have the 44. I think FDU is Front Diff Unit (pumpkin)
1637849679963.jpeg
 
Advertisement

Allmoparparts.com
 
Advertisement
Top