05 Tacoma, 75W-90 Royal Purple, 28,200mi rear diff

Messages
214
Location
Eastern North Carolina
2005 Toyota Tacoma 4x4 4cyl. Owner's manual specs SAE 90 for the rear differential. This fill was in the rear end for nearly 30k. I picked Royal Purple 75W-90 specifically for its "near" SAE 90 upper viscosity. The RP website used to have it listed around 21cSt, but now has it around 19cSt. The Blackstone report said the viscosity was within allowable limits, but I think this oil has sheared pretty bad. Wear looks pretty good though. It was replaced with Redline 75W-90. ALUMINUM 1 CHROMIUM 1 IRON 121 COPPER 0 LEAD 0 TIN 0 MOLYBDENUM 131 NICKEL 0 MANGANESE 3 SILVER 0 TITANIUM 0 POTASSIUM 0 BORON 104 SILICON 25 SODIUM 2 CALCIUM 35 MAGNESIUM 1 PHOSPHORUS 2289 ZINC 18 BARIUM 0 SUS Viscosity @ 210°F 71.3 cSt Viscosity @ 100°C 13.29 Flashpoint °F 365 Water % 0 Insolubles % TR
 
Messages
8,756
Location
RI
Normal visc drop for their 75w90. One reason why some manuals shift well with it. Looks good but Fe could be a little lower. Other then the shear, no reason not to use the RP fluid. How many total miles on vehicle? how did the drainplug magnet look like?
 

gonesurfing

Thread starter
Messages
214
Location
Eastern North Carolina
Right around 60K on the vehicle, but the rear diff was swapped out by the dealer around 15K due to noise issues. This is the second fill on the diff, the first was bulk 80W-90 from the dealer (I asked). The drainplug had some iron paste on it, but nothing abnormal relative to other differentials I've changed. The fluid was clean, no sparkle to it.
 
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