Rob, I just changed my diff oil. There is plenty room in there to fill the diff with tall bottles and a 6" hose on the end. No problem at all.

But I would think the cheapest way to go would be a manual fluid pump that looks like a grease gun.

One of this design: http://automotive.hardwarestore.com/...mp-661998.aspx

James

PS here is something that is really inexpensive that should work just fine: http://automotive.hardwarestore.com/...mp-126773.aspx