burnt gear oil

[4Runner]

k well i am doing a SAS on my 94 4runner and i am putting in a knew rear end to and sense that is the easy part of it i decided to start their, well when i pulled the rear apart the oil smelled REALLY burnt. it is knew i changed it last easter so not even a year ago and was still full whats this from????

 

[Max Power]

Gear oil typically lasts a long time. You could have used the wrong weight but even then it most likely shouldn't burn up. Do you pull anything?

 

[4Runner]

nothing at all i took the tow package off so that i wouldnt pull with it. i cant remember what i used but its the same thing my dad runs in his YJ. everything i can see looks good to like all the bears and such