so doing a fluid change tonight and had a brain fart.... I put Mobile 1 gear fluid in my primary... well i noticed as soon as i got it in and drained it, being that that was my only gear lube i put it from there into the trans where it belongs... Needless to say it had a bit of mobile one oil mixed in with it after the drain, I then put in Mobile one oil into the primary and buttoned it all up, Do yall think that slight mixture could pose a problem? anyone else use mobile 1 20/50in the primary?

 

I think there are a number of people on here using 20w50 M1 in their primary. Do a search for Mobil 1 + primary and it might bring up thethreads where this is discussed. I don't think mixing a little leftover oil in any of the holes is a problem. The ratio of new oil to leftover oil is too great to make a difference and the new oil should be dominant in the specifications of the mix.

 

Should not be a problem. I have heard that if you do mixoil itcan cause breakdown of the oil faster, but the test was done by adding a qt of different oil in the engine.