Overfill FC rear diff?
 

Hey all,

Thought I should post here since most likely you folks tried this already. As I remember, manual says like 1.1 quarts. I probably filled to 1.5 or so. What issues would I possibly see? Reason I am wanting to do this is because more fluid means more ability to adsorb heat and more ability to dissipate from sidewalls.

There are absolutely no current leaks on any of the seals.

Thanks,
Ben

well, if you filled it through the fill hole and the car was more or less level at the time, it's pretty difficult to actually overfill it. Did you fill it on the bench or something like that?

-b

might come out of the vent?

No. Jack up the rear and fill. Car was not level.

It'll increase the drag on the diff and will likely increase heat generated. Fill it to the proper level, no more, no less. If you're really concerned, look into getting a diff cooler and pump to keep it nice and cool (be sure to use a thermostat).

yea... no more no less.

heat and pressure are directly related. fluids expand when heated. overfilling can lead to blowing seals, actually running hotter because of the added friction etc... that is why on big trucks we actually underfill about a fingernail length to allow for the expansion.

the last two posts are true
overfilling transmission and diff does nothing but increase heat - and does not help lubrication at all - after all, they are pretty much splash lubricated