Technical Question Differential Oil Change
Thread Starter
Intermediate
Joined: Nov 2014
Posts: 39
Likes: 8
Technical Question Differential Oil Change
Hi, I have a technical question about changing the differential oil. When the oil is drained, does the oil cooler also empty completely or does a residual amount of the old oil remain in the cooler?
Best Regards, Stefan
Best Regards, Stefan
Safety Car
Joined: Feb 2002
Posts: 3,726
Likes: 368
From: Montoursville Pa
either can happen, the only way to be sure it is correct is to run it in gear on the lift after the fill then check it
Thread Starter
Intermediate
Joined: Nov 2014
Posts: 39
Likes: 8
How can it be that sometimes it can happen and sometimes it doesn't? I do not understand that. The oil is pumped into the radiator by the oil pump. Is the oil pumped into the radiator from below and the excess oil simply runs back into the differential at the top of the radiator? In this case the radiator would always be filled with oil. Or is the oil pumped from above into the radiator and it simply runs back into the differential at the bottom? In this case, the cooler would always have to be empty when changing the oil.
Race Director
Joined: Sep 2000
Posts: 11,149
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From: Missouri City, TX
I have never been able to add but another 2 or 3 ozs so I am of the opinion that the cooler does not substantially drain. Keep in mind also that GM considers it full if the level is within a 1/4” of the Fill port bottom opening.
