My passenger side brake backing plate has been repaired so it's time to put it back on the axle tube, reinstall the axle and replace the differential fluid. I'll certainly clean the inside of the cover but how far should I go in cleaning the inside of the housing? Do you guys recommend using RTV or an actual gasket to seal the cover to the housing? Also, what weight of fluid should be used? I have a 7.5" 3.08 non-locking rear in an '84 Thunderbird.
Thanks in advance!
I usually run 75W90 gear oil. Use "The Right Stuff" RTV for the differential cover, no gasket.
Paper gaskets are for differentials. Unfortunately no one makes anything like THIS (http://"https://www.summitracing.com/parts/lub-llr-f880/overview/") for a 7.5....
It's because they're too busy designing diapers for when they scatter the gears.
You're thinking more the GM 7.5 ;)
Remove spider gears; problem solved.
I usually just use paper towels to get as much of the excess oil out of the housing. Then I use carb cleaner to more or less wash everything down and then put a paper towel in the bottom of the housing to soak all of that up as well. I then use compressed air to really dry the housing, gears, and posi out as much as possible before putting the diff cover back on. Install the diff cover using RTV and I usually let that sit for at least an hour before putting the gear oil in. I run Mobil1 synthetic gear oil in both of my Fox's and for those with a limited slip rear don't forget the clutch additive.