Aluminum Differential Cover Thermal Results

Blacklane wrote:
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.

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.


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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.