Temps pre & post diff cover change

[SteveSRT8]

Originally Posted by atikovi
The thermal mass of the 200 pound axle housing itself would suggest a 2 pound cover would have minimal effect in temperature reduction.


Agreed. As would the typical location at the rear of a hard working truck with quite a bit of heated air from all that engine work going on up front. Then put the so-called "cooling" fins on the back side!

I would love to see some real world testing...

 

[GumbyJarvis]

While I don't remember the exact numbers, I did see a cooler temperature running Synpower 75w140 over the OEM 75w140 in my truck.

I drained it when I bought it used at 15,XXX miles, out with the Dino whale blubber green snot stinky stuff and in with the Synpower.

 

[kehyler]

Originally Posted by 2015_PSD
Originally Posted by spasm3
Originally Posted by kehyler
Let's try and get back on topic, which is the pursuit of data-verification of lower temperatures.

Would we admit the following experiment as valid:

(1) drive the same stretch of long highway multiple times & measure the temperature of underside of the differential (not the cover) with an infrared temperature sensor?
(2) change the differential cover & fluid
(3) drive the same stretch of long highway multiple times (at same ambient temperature) & measure the temperature of underside of the differential (not the cover) with an infrared temperature sensor?

When then compare the temperatures obtained in (1) against those in (3) to see if the fluid cooler.


I think you would have to change gear oil first, put the old cover back on, then check temps. Otherwise you are comparing worn possibly lower viscosity sheared oil against new oil with the new cover.
You would also need to have a temperature probe directly in the fluid to eliminate any variables from the external reading and would need to have controlled "runs" for consistency otherwise, it is semi-guess work.


What variables from the external reading and why would they have a significant impact?

 

[CarbonSteel]

Originally Posted by kehyler
Originally Posted by 2015_PSD
Originally Posted by spasm3
Originally Posted by kehyler
Let's try and get back on topic, which is the pursuit of data-verification of lower temperatures.

Would we admit the following experiment as valid:

(1) drive the same stretch of long highway multiple times & measure the temperature of underside of the differential (not the cover) with an infrared temperature sensor?
(2) change the differential cover & fluid
(3) drive the same stretch of long highway multiple times (at same ambient temperature) & measure the temperature of underside of the differential (not the cover) with an infrared temperature sensor?

When then compare the temperatures obtained in (1) against those in (3) to see if the fluid cooler.


I think you would have to change gear oil first, put the old cover back on, then check temps. Otherwise you are comparing worn possibly lower viscosity sheared oil against new oil with the new cover.
You would also need to have a temperature probe directly in the fluid to eliminate any variables from the external reading and would need to have controlled "runs" for consistency otherwise, it is semi-guess work.


What variables from the external reading and why would they have a significant impact?
How will you compensate for the increased quantity of oil with the aftermarket cover? Will you run it longer or harder or? Reading externally has variables--different location, the rate of thermal transfer to the metal, etc, reading the fluid directly should not. In the end if the conditions are not controlled and repeatable, then the results will interesting, but highly debatable.

 

[kehyler]

Originally Posted by 2015_PSD
Originally Posted by kehyler
Originally Posted by 2015_PSD
Originally Posted by spasm3

...


...


What variables from the external reading and why would they have a significant impact?
How will you compensate for the increased quantity of oil with the aftermarket cover? Will you run it longer or harder or? Reading externally has variables--different location, the rate of thermal transfer to the metal, etc, reading the fluid directly should not. In the end if the conditions are not controlled and repeatable, then the results will interesting, but highly debatable.

I proposed measuring from the same point on the underside of the diff (not the cover) so the rate of thermal transfer to the metal would be the same.

I wouldn't really compensate for the increased quantity of oil, that seems to be part of the benefit of the having a new cover, and therefore part of the test.

You said "etc," what are the items that you didn't include?