I changed the front diff oil on Sunday and today did a 25-mile journey, punctuated by a 10-minute stop at the halfway point. Fairly gentle run, about one-third on country lanes, two-thirds A-road.

When I got back home, just out of curiosity, I measured the temperature of the front diff with an infra-red/laser thermometer and got a reading of 70 deg C which was higher than I expected. I must say that I've no knowledge of what temperature a diff usually runs at so for comparison I measured the rear diff (48 deg C), then the transfer case (60 deg C).

Somewhat surprised at the temperature difference between the front and rear diffs, especially given that the rear diff is said to do a bit more work than the front.

What are your thoughts on this guys – why would the front diff be running hotter than the rear? Is 70 deg C too hot? 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)