Aluminum Differential Cover Thermal Results
I recently installed a finned aluminum differential cover from PML Covers on my 2012 Chevrolet Avalanche 1500 that I intend to use for towing a travel trailer. In my previous truck, I had to replace the differential bearings, which is not a small task, so I wanted an easy way to drain and fill the fluid regularly in the hope of avoiding the same problem in my newer truck. So I wanted a good differential cover with drain and fill plugs.
I powder-coated the cover in gloss black to match everything else under my truck. Installation was simple. I replaced the differential fluid with AMSOIL Severe Gear 75W90. I used a paper gasket and used medium loc-tite on the screws. (I once had some diff screws loosen causing a loss of fluid).
I have a thermal camera and I had a chance to take thermal images of the differential before and after installing the PML cover. I took both images after towing a trailer for about an hour on a highway, followed by about fifteen minutes of slower, steady driving. I could not perfectly duplicate the ambient temperature, so one image is at 70F degrees ambient and the other is at 80F degrees. In the thermal images, you can determine the ambient temperature by looking at the frame temperature in the background, which is pink/purple/blue.
I assumed that the stock differential and axle had plenty of heat-dissipating area, since the oil can flow all the way down both axle tubes. A few square inches of aluminum fins would not add much. The thermal images revealed a different story. The stock differential temperature was mostly 170-200 degrees F while the PML differential was mostly 140-150 degrees F. The axle tubes are green colored, indicating that little heat is transferred down the axle tubes.
Click For Full-Size Image.
Click For Full-Size Image.
Click For Full-Size Image.
Full disclosure: I also sent this info to PML Covers who posted it on their website and sent me a tee shirt, so I guess you could say I have a bias. However, I think these results would be applicable to any similar differential cover.
I powder-coated the cover in gloss black to match everything else under my truck. Installation was simple. I replaced the differential fluid with AMSOIL Severe Gear 75W90. I used a paper gasket and used medium loc-tite on the screws. (I once had some diff screws loosen causing a loss of fluid).
I have a thermal camera and I had a chance to take thermal images of the differential before and after installing the PML cover. I took both images after towing a trailer for about an hour on a highway, followed by about fifteen minutes of slower, steady driving. I could not perfectly duplicate the ambient temperature, so one image is at 70F degrees ambient and the other is at 80F degrees. In the thermal images, you can determine the ambient temperature by looking at the frame temperature in the background, which is pink/purple/blue.
I assumed that the stock differential and axle had plenty of heat-dissipating area, since the oil can flow all the way down both axle tubes. A few square inches of aluminum fins would not add much. The thermal images revealed a different story. The stock differential temperature was mostly 170-200 degrees F while the PML differential was mostly 140-150 degrees F. The axle tubes are green colored, indicating that little heat is transferred down the axle tubes.
Full disclosure: I also sent this info to PML Covers who posted it on their website and sent me a tee shirt, so I guess you could say I have a bias. However, I think these results would be applicable to any similar differential cover.
