Most fill plugs can be removed with a 3/8 " ratchet and a short extension. The square end of the extension goes right in the fill plug.
Only the filler plug. You have to remove the cover to drain the oil.
There is an upper filler plug and a bottom drain plug in each differential. R&I (Removal and Installation) the filler plug first then the drain plug until the differential completely empties out. Then reinstall the bottom drain plug and add 90W gear oil which usually comes in a squirt bottle so you can add it into the upper filler plug. You should fill it up until the level is right at the bottom of the threads of the filler hole.
The differential fluid on a GMC Jimmy is changed by removing the drain plug, draining the fluid, and re-installing the drain plug. The filler plug can then be taken out, fluid added until it reaches the bottom of the filler hole, and the plug re-installed.
Plug on the side of the differential. Location varies depending on the differential but should be easy to spot. If changing oil, you need to remove rear cover to drain (no drain plug), clean, seal and refill until oil begins to come out of the filler hole.
on a 2002 there is a drain plug on bottom and the filler plug is on the side it takes a little less than 3 qrts. fill till fluid runs out of filler hole
Changing differential fluid is no different from changing engine oil. You just have to make sure that you find the correct drain plug on the bottom and the correct filler tube on top. --Ken On some differentials you have to remove the cover plate to drain.
On the upper right (passenger for a left hand drive vehicle) side of the differential, there's a plug. IIRC, you need a 3/8" drive ratchet to remove it. That's where you add your diff fluid.
If doesn't have the rubber plug in the back cover it will have a threaded metal plug on the passenger side of the carrier housing near the pinion yoke. It takes a 3/8" square male drive to remove it.
Thereis a tag on the filler plug for the differential. On my 2001 300M the tag ready 80 to90 wt hypoid gear oil only.
there is no drain plug, you have to remove the whole cover to drain fluid.
There is a check and fill plug on the side of the transmission close to the cv axle. It is most likely on the passenger side of the differential. The fluid should be full till it is just before running out of the plug hole.
there should be a square opening on the front differential cover. There, you can install a 3/8 inch ratchet. the plug itself is like a socket.