Crankcase capacity?
What is the actual number of quarts of oil that it takes to fill a 5.9 to the full line on the dipstick? Sounds dumb, but I have a Cummins manual that states 15qts. My dipstick shows full at 12qts.(filter included).
Is an overfill by 2 qts a problem?
I don't trust dipsticks much.

 

It should be 12qts including the filter.. I have always ben told that overfilling can cause premature failured of oil seals....particularly the rear main..

 

There's an issue where some of the 3rd gens had incorrect dipsticks, IIRC. Other than that, I'd stick with the dipstick. One quart over wouldn't hurt, maybe adviseable in an engine that is using or has alot of blowby. But three is pushing it.

 

I was fixing to post and ask the same question.

Have had a 2006 Dodge 5.9 w/manual transmission. in the family (also have DMax ....don't be hard on me.), but using truck differently with ranch activity, and I've taken over the maintenance. Before we had it done, since company would pay...not the case now since the truck is being used in a differnet role now.

This is the first oil change I've done. Manuall says 12qts......and that took it to the add mark on the dipstick. And my very thoughts....what's right, is the dipstick wrong...or manual wrong? I did a filter change.

 

Over filling the crankcase or transmission will cause airiation. (bubbles in the oil) which will then start the motor of oil and will cause premature failure of the motor or trans.

 

12 quarts fills my 91 to the add line . . 14 is full line. Both with filter.

 

12 quarts puts my 93 right at the full mark. They have a habbit of reading low if the engine is not fully warmed and allowed to sit for 10 min or so. This time of year I have to let the new oil run for a few minutes to get it warmed up.