Differential Gear oil temp with water in it VS with out

[RPMRPM]

Hey I’m not sure if this is in the right spot if not please move it to where it belongs.

I’m not sure if anyone on here will know the answer to this question, but I have a full sized overland rig (98 dodge diesel) and I just put a limited slip front diff (so I can have true 4WD) with lockout free spin hubs in the truck so I put a diff temp sensors in the front to make sure it’s not getting too hot and I decided to put one in the back while I was at it and run them on my overhead gauge pod and I was wondering if I would also be able to tell if there’s water in the gear oil because of temperature changes if anyone knows any help would be appreciated

 

[rruff]

No experience, but... the phase change when water boils might be detectable. Say if temperature is increasing, then pauses for awhile at the boiling point of water until it's vaporized, then continues rising.

 

[RPMRPM]

No experience, but... the phase change when water boils might be detectable. Say if temperature is increasing, then pauses for awhile at the boiling point of water until it's vaporized, then continues rising.

Good point I’ll have to do some digging on that thanks

 

[IdaSHO]

Interesting question
something else to consider....

With water in it, it will turn into a milkshake.
I figure the air in that milkshake will likely effect the accuracy of the sending unit itself

 

[(none)]

Run a test for us! get baseline readings as it is now, then dump in a quart of water and let us know if the temp changes.

For science

 

[RPMRPM]

Interesting question
something else to consider....

With water in it, it will turn into a milkshake.
I figure the air in that milkshake will likely effect the accuracy of the sending unit itself

I’m not entirely sure if that would affect how my gauges are ran, I got a 60 front like I said before and an 80 rear and the differential covers mag hytech makes for the dana axles has a probe similar to a EGT’s gauge sending unit if you’re familiar with diesel engines that goes all the way down to Almost the bottom of the differential once I get the lines ran, I will report back, I’ll probably call my account rep at Yukon Gear since I do a ton of volume with them for building these trucks for drag racing in sled pulling they might be able to shed some light to

 

[RPMRPM]

Run a test for us! get baseline readings as it is now, then dump in a quart of water and let us know if the temp changes.

For science

I genuinely may actually do that for my own knowledge, if my account rep at Yukon Gear can’t answer the question that is, I’ve got quite a few of these axles laying around in the backyard that I don’t need any more, I may stuff one of them under my other truck and get a baseline reading on my overlanding rig with 410s, and then since one of the axles I have back there has 410s also get a with water reading and see if they’re different

 

[NatersXJ6]

I’m not sure you could see it only in temperature, at least until after the failure of gears and bearings truly happened.

I did a semi-science experiment once when I accidentally left an oil pan open over a weekend and it got rained in strongly. I was left with about 4 gallons of probably 60-40 water oil sludge (milkshake) and of course, you can’t take that in for recycling. I used a metal oil pan over a small charcoal fire and I got the oil back. It would boil, laser thermometer said the surface of the foam was about 165, and when the bubbles stopped, the temp started climbing to maybe 250 and all the foam was gone and I was back to slightly less than 2 gallons! It took all day over a very small fire far out on a concrete apron, but it worked!

 

[RPMRPM]

I’m not sure you could see it only in temperature, at least until after the failure of gears and bearings truly happened.

I did a semi-science experiment once when I accidentally left an oil pan open over a weekend and it got rained in strongly. I was left with about 4 gallons of probably 60-40 water oil sludge (milkshake) and of course, you can’t take that in for recycling. I used a metal oil pan over a small charcoal fire and I got the oil back. It would boil, laser thermometer said the surface of the foam was about 165, and when the bubbles stopped, the temp started climbing to maybe 250 and all the foam was gone and I was back to slightly less than 2 gallons! It took all day over a very small fire far out on a concrete apron, but it worked!

Damn ok thanks sounds like my idea won’t work for me then

 

[wheelerfreak]

I genuinely may actually do that for my own knowledge, if my account rep at Yukon Gear can’t answer the question that is, I’ve got quite a few of these axles laying around in the backyard that I don’t need any more, I may stuff one of them under my other truck and get a baseline reading on my overlanding rig with 410s, and then since one of the axles I have back there has 410s also get a with water reading and see if they’re different

I wouldn't do that "test" in a differential I plan to keep using. I have gotten water in my front diff and it turned the gear oil into a thick milkshake mess that was a PITA to get it completely cleaned and cleared out. I had to pull the cover and drain it then thoroughly clean it out, then refilled it with fresh gear oil. I decided to just check on it about 50 miles later and the new gear oil was a mess as well. It took about 4 drain, refill, and run 20 miles cycles to get all the mess out.

 

[broncobowsher]

Temp will detect water in the oil only after the parts are overheating from lack of proper lubrication.
The answer is no. You won't use a temp gauge to prevent damage from running with water in the diff. But it might let you know the axle is about to lock up just before the axle locks up. Which would have little to do with having water in it, other then running with water would make it happen easier.