Make sure that you remove the FILLER plug FIRST. There have been instances where people have drained the oil only to find that they couldn't get the filler plug out. You then have to add the oil through the shifter mechanism.
I would like just to check my trans/diff fluids. However I can probably only check it if either the front or back ends are raised individually.
Is this going to throw off what the normal level should be? What color/consistency should be considered "normal" of both fluids?
Correct me if I'm wrong but the correct levels should be right at the opening of the filler plug.
I changed the oil in the differential and transmission a couple of weeks ago. It was pretty straight forward. Drove the car for a 20 minute run. Up on the ramps, jack up the rear end, lower it onto jack stands, and crawl under. The worst part was trying to get the oil into the filler holes. I borrowed a filler hose from a co-worker, but it was quite the task getting the oil into the cases when the bottles were nearing empty. If they only made like a 1 liter industrial syringe. You could inject the oil right into the case! The real awful part was that it was 98 degrees (F) out and there was 100% humidity while I was laying on the hot asphalt driveway. Musta lost a few pounds of sweat that day. I was amazed at the gunk (metal filings?) and metal pieces (1mm or so) that were on the magnetic drain plugs!
On the plus side, it does seem to shift better and makes less whine when I'm driving along now. I could only have put in more 85w-90 than I took out, I'm hoping anyway. Also had to buy the correct sockets to do the job. Once again I found that info here on the bb! Couldn't track down a 12mm hex socket, as soon or as cheap as desired, so I bought a 12mm hex wrench from Sears. Used an improvised breaker bar and that did the trick getting the filler plugs off.
What I found out in my instance, is that for the trans., the car should be level. Unless you get it on a lift, you'll have to jack up both sides. Make sure it's safe with jack stands (and not just jacks) before you venture underneath.
For the rear, you're able to do it without jacking the car up. It is a ballbuster to refill the rear. The rear gear just about fills up the hole at the filler plug. I had to put a "real" small tube attached to the suction gun to refill. It just about fit between the gear and the hole of the filler plug.
I would like to point out that someone in this BB used a 90 degree plastic fitting from Home Despot screwed into the fill hole with a long hose on the other end for the oil to get in. the threads of the coupling did not exactly match those in the trans case, but the plastic coupling's are soft and will distort to fit.
I think this is a good idea. I suggest you search this forum. There might have been pictures I don't remember.
I did mine in a scientifically correct, but very painfull, way. I put a hose through the top of the oil jug, then injected air with an electric bicycle pump into the container. Sounds great in theory but really does not work because of the oil viscosity. It took along time for the air to push the oil.