Interesting read on Diff fill capacities.

[itsaguything]

Or…. measure what you drain…
One thing for certain, heated fluids expand. Overfilling can be catastrophic. There are many resources online from differential manufacturers/experts that emphasize the importance of not overfilling the case.

 

[ktm525]

You are assuming it was filled correctly before..

 

[ftillier]

Why in the world would engineers set the fill port higher than the fill level? Did they start out filling up to that level and then realized that they were blowing seals so reduced it?

 

[ktm525]

Probably. The LR3 had poorly designed air vents that tended to clog. Maybe less fluid reduced leaking diffs? Keep your vents clear and fill to spill is what I have done for the past 10 years and 100k's miles. Seems to work. Land Rover is so worked up about fill level but then spec a 10 year oil change interval? Whatever.

Overfilling a diff can cause some MPG loss due to increased drag. I wonder if the Land Rover instructions are trying to save 0.002 MPG? You know the same stupid decisions that had them replace the V8 with the blown six? and 5W-20 oil...

 

[f1racer328]

replace the V8 with the blown six?

replace the V8 with another V8 that has two cylinders capped off, oh and yeah lets supercharge it too.

 

[ktm525]

also: add a 8 speed gearbox, lose a bunch of power and and gain maybe 1 MPG..