Here the deal on my Rear Diff.......

[DBoudreaux]

I called dealer to find out how much oil the rear differential took on my 2008 4500. (Called dealer because manual doesnt state that info!!!) Well all in all I misunderstood him, he said 8. 8pts, I thought he said quarts. Got to 6qts and it started flowing out fill hole. Was told oil had to be 1/4 inch below fill hole... ... . is it "that" important to leave a 1/4 inch?? I always filled till it started coming out (on older cars and trucks) and put plug in... ... . but have not done so with this newer truck so I'm not sure if its a must or not??

 

[HBarlow]

If you try running it filled to the fill hole it will probably run out of the vent at the top once it gets warm and expands.

 

[Bob4x4]

Gear oil run at too high of level may foam and loose some lubricating qualities

 

[DBoudreaux]

Thx for the quick response. I did take some out, but I'm guessing I have about 1pt more than the dealer said I needed. So I shouldnt have heart failure if it does come out the vent at the top?

 

[Bob4x4]

:-laf You should be fine.

 

[DBoudreaux]

Forgot to mention I put Royal Purple 75w-90. Read some good reviews on it so I thought I'd give it a shot.