Axle Temp Gauge Project

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Sep 26, 2010
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The weather and life in general finally aligned and I was able to complete my project. After playing contortionist under the dash for several hours, my back is reminding me that I am still alive.
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All in all, it was not an overly difficult task and my fish tape paid off in spades again as I routed the ¼" loom covered sensor wiring through the frame securing the loom with tie-wraps to the rear axle vent tube and the lower fan shroud housing above the front axle. I used the rubber firewall boot on the passenger side to pass the wires into the interior. Power was pulled from the ignition/accessory wire (pink/orange) in the upfitter wire pack under the dash and I tapped into the ambient lighting wiring in the passenger footwell, to provide the gauge lighting. A ½" hole was bored by hand using a drill bit to pass the wiring from under the dash to the gauge cups.


Speaking of the dash, it was necessary to remove the glovebox, the front bezel (it has the start stop button in it), and the 8.4" LCD panel to gain access to the space behind to route the wires. This trim tool kit was invaluable to removing everything without breaking anything (https://www.amazon.com/gp/product/B07RRNDBYG/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1)


Each sensor has two wires (power and ground) and the gauges require three (power, ground, and illumination) so there are total of 5 wires in the red & black braided loom (https://www.amazon.com/gp/product/B075VR7ZQS/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1) going into each the gauge cups.


I had considered fabricating some protection plates for the sensors (using the axle cover screws to mount them), but the sensors are fairly high up and tucked behind some of the suspension components so they may not be needed. I have a new Metal Cloak covers coming so I may look into that after I have them mounted. The temperatures sensors are mounted directly into the gear oil splash stream and they work very well thus far. I can confirm the ring gears do not turn in the front axle because it has not registered any temperatures at this point and I know the gauge is working.


The rear temperature when to 160°F during a 75+ MPH dash for about 20 minutes. I will see how the temperatures fare on a road trip whenever the lock down is over. At any rate, I am very happy with the results and like the aesthetics of the installation.


Enjoy!


Rear Axle Cover:
[Linked Image from iili.io]


Front Axle Cover:

[Linked Image from iili.io]



[Linked Image from iili.io]


[Linked Image from iili.io]


[Linked Image from iili.io]
 
I've never seen the need for axle temp on a street vehicle, were you just bored and had excess cash laying around? or do you honestly see a need for this? I can think of a whole host of other critical things I'd want to monitor....

Also you do realize with the sensor being at the top, you aren't getting actual fluid temp being the sumps are usually only about 1/2 full...
 
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Originally Posted by racin4ds
I've never seen the need for axle temp on a street vehicle, were you just bored and had excess cash laying around? or do you honestly see a need for this? I can think of a whole host of other critical things I'd want to monitor....Also you do realize with the sensor being at the top, you aren't getting actual fluid temp being the sumps are usually only about 1/2 full...
FCA reduced the oil capacity by at least 50% with the new Dana 44 axles versus the previous version (it has a total capacity of 1.6QTs) and the UOA at 5K was the worst one I have ever seen and the 10K UOA was not much better. With such a low capacity of the sump, I want to know what the axle temps are while on extended runs.

Why would I not be measuring the actual axle fluid temperatures? The probe is directly in the oil being slung over the ring gear towards the pinion gear. Mag-Hytec has their temperature probes in about the same location so I am curious why you do not think I am measuring the fluid temperature.
 
Even if the temp sensor is a few degrees lower than the hottest spot, it should still provide an increasing temp readout that either feeds paranoia, or reminds to change the fluid often enough to feel like you did what you could, but if it's really bad enough that you can't go 5K mi, that is going to be a problem eventually unless you take even more elaborate measures.

Have you looked into whether there is a finned diff cover for that to aid in cooling? Does it have a drain plug? I'd want that even more than the temp sensor if you're going to be changing fluid at crazy short intervals.
 
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When I saw your other post on adding/welding the bungs to the Metalcloak diff covers, I didn't realize you already had this set up in the existing Dana 44 covers.

It looks good, but I'm curious, as you said you won't be rock crawling, why would you buy $200+ covers designed for off road bashing, and then install compromising sensors that take away from the covers? Why not just stick with the Dana covers? If you're not rock crawling, what's the difference?

It's your coin, but as a hardcore wheeler, I'm curious. Thanks man.
 
Be careful of aftermarket cooling diff covers. The simplest looking stock diff covers fit closely to the ring and movement creates a pumping action up the cover that cools and flows oil to the carrier bearings. Aftermarket covers with square box higher capacity or cooling fins do not create the pumping action and the bearings are not bathed in oil properly.

160 degrees sounds really hot under low load cruising. Methinks something is going on in there. Heat = friction ...maybe pinion depth is off? My old ford pinion depth was off brand new and you could hear it at certain speeds. Took in for warranty and they would only change fluid. Just after warranty the bearings gave up.
 
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Originally Posted by Dave9
Even if the temp sensor is a few degrees lower than the hottest spot, it should still provide an increasing temp readout that either feeds paranoia, or reminds to change the fluid often enough to feel like you did what you could, but if it's really bad enough that you can't go 5K mi, that is going to be a problem eventually unless you take even more elaborate measures. Have you looked into whether there is a finned diff cover for that to aid in cooling? Does it have a drain plug? I'd want that even more than the temp sensor if you're going to be changing fluid at crazy short intervals.
It is my hope that (sooner than later) the wear metals will wind down so that I can extend the OCI out quite a bit. I changed the fluid at 5K, but did not change at 10K (only sampled). The covers for this new D44 axle are limited and I have not seen any of them which are finned and since those are typically aluminum, it would not be a good choice for off-roading. I have two Metal Cloak covers coming (5/8" thick nodular iron), but they do not increase the capacity nor do any of the others I have seen on the market.

Both axles do have drain plugs so the R&R is simple, though they also have silicon metal embedded gaskets so pulling the covers is not a big deal. I have skid plates to install on both axles because the drain plugs are underneath and a few on the Jeep forums have knocked it out by hitting/landing on a rock while off-roading. The covers and skid-plates will be installed after drilling/tapping/power coating in the near future.
 
Originally Posted by Kawiguy454
160 degrees sounds really hot under low load cruising. Methinks something is going on in there. Heat = friction ...maybe pinion depth is off? My old ford pinion depth was off brand new and you could hear it at certain speeds. Took in for warranty and they would only change fluid. Just after warranty the bearings gave up.


160*F is a normal temp for a Dana 44.

Typical oil capacity for a standard Dana 44 is about 1.9qts.
 
Originally Posted by Kawiguy454
Be careful of aftermarket cooling diff covers. The simplest looking stock diff covers fit closely to the ring and movement creates a pumping action up the cover that cools and flows oil to the carrier bearings. Aftermarket covers with square box higher capacity or cooling fins do not create the pumping action and the bearings are not bathed in oil properly.

160 degrees sounds really hot under low load cruising. Methinks something is going on in there. Heat = friction ...maybe pinion depth is off? My old ford pinion depth was off brand new and you could hear it at certain speeds. Took in for warranty and they would only change fluid. Just after warranty the bearings gave up.

None of the covers for the D44 axles in the late model Jeeps are "flat back"; all of them mimic the shape of the OEM so no issues there. I am not sure 160°F is abnormal (yet); I had much higher temperatures (200+) when towing in my Fords and those had double and nearly triple the fluid capacity. I have a 7 year unlimited mileage warranty so if I need to exercise it, it is there. From what I have seen, FCA is fairly stupid to have lowered the capacity in the quest for increased MPG (it's a box with 4.10 gears running down the highway--do we really think the rear axle oil viscosity/capacity is going to impact MPG?) .

They even specify 75W-140 for towing, and yet my Rubicon (with the towing package) came with 80W-90 in it. Hopefully, the wear metals will settle down and I now have a way to watch the axle temperatures to see what is happening there. I have not been able to find any data on "what is normal" for these new D44 axles, but I keep looking for it. I may have to hit Dana up and see if they will tell me, but since the final design/specification was FCA, they may not be willing.
 
160*F is a bit too high in your context .
A higher viscosity grade (or two) gear oil is required ,if it's mine .
 
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Originally Posted by zeng
160*F is a bit too high in your context .
A higher viscosity grade (or two) gear oil is required ,if it's mine .


Two higher viscosity grades for driving around town?!?!?!

160*F is normal for a Dana 44. When it gets some miles on her, she'll even drop down a bit.
 
Originally Posted by zeng
160*F is a bit too high in your context .
A higher viscosity grade (or two) gear oil is required ,if it's mine .

Zeng - it has Amsoil 75W-140 in it; not much higher that I can go :p
 
Originally Posted by Zaedock
When I saw your other post on adding/welding the bungs to the Metalcloak diff covers, I didn't realize you already had this set up in the existing Dana 44 covers.

It looks good, but I'm curious, as you said you won't be rock crawling, why would you buy $200+ covers designed for off road bashing, and then install compromising sensors that take away from the covers? Why not just stick with the Dana covers? If you're not rock crawling, what's the difference?

It's your coin, but as a hardcore wheeler, I'm curious. Thanks man.
I got a deal on them too good to pass up; had a friend that sold his Jeep a while back and he never go around to installing them. They are starting to collect a bit of surface rust (he never had them painted or coated) so I will send them out to be powder coated. I do some off-roading, so it is not a complete "waste" and the sensors are nearly vertical at the top of the housing. I would be more concerned with the ELD module wiring versus the sensors.
 
Originally Posted by Zaedock
Originally Posted by zeng
160*F is a bit too high in your context . A higher viscosity grade (or two) gear oil is required ,if it's mine .
Two higher viscosity grades for driving around town?!?!?!
160*F is normal for a Dana 44. When it gets some miles on her, she'll even drop down a bit.
It has 75W-140 in it, so I cannot go up too much higher and really do not think I need to do anything at this point.
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160°F is not that hot, I have had over 200°F in my Fords. It will be interesting to see if it comes down in temperatures after more miles are on it as well as the wear metals reducing. Do you have a source for normal operating temperatures on these guys?
 
I love it, so awesome. Have you checked the drain plug thread on the Metal Cloak covers? I ask because the Ford Performance diff girdles / finned coolers either have a separate port for a temp probe, or they want you to use the drain plug for the temp probe. The factory cover on my car is setup for the GT-500 diff cooling kit which has an electric pump and small cooler up by the radiator. I just haven't spent the money for that setup yet
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IMG_8585(1).jpg
 
Originally Posted by 2015_PSD
It has 75W-140 in it, so I cannot go up too much higher and really do not think I need to do anything at this point.
banana2.gif


160°F is not that hot, I have had over 200°F in my Fords. It will be interesting to see if it comes down in temperatures after more miles are on it as well as the wear metals reducing. Do you have a source for normal operating temperatures on these guys?

If you are restrained to fully synthetic , then a 80W140 typically of KV@40*C 230 cSt would likely not help much in dropping gear oil temperature here .

A mineral 85W140 at KV@40*C of 420-440 cSt would surely helps in lowering oil temperature by as much as 15-20*F IMO , not so much with KV@40*C 320-350 cSt alternatives .

More miles might drop the temperature by 4-8 *F , IDK .

Anyway, it is your coins .
 
Originally Posted by bdcardinal
I love it, so awesome. Have you checked the drain plug thread on the Metal Cloak covers? I ask because the Ford Performance diff girdles / finned coolers either have a separate port for a temp probe, or they want you to use the drain plug for the temp probe. The factory cover on my car is setup for the GT-500 diff cooling kit which has an electric pump and small cooler up by the radiator. I just haven't spent the money for that setup yet
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The D44 axles in JL series Jeeps have drain plugs in the housing itself (which is a problem for hard core rock climbers). Metal Cloak has axle skid plates for the front and rear axles made of 3/16" steel plate to cover those drains. The Metal Cloak covers only have the fill plug which is about halfway up the face of the cover and is 1/2" NPT, but I know what you are talking about because Mag-Hytec has one like yours along with a dipstick port.

That cooling kit for your GT sounds interesting What does it cost?
 
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