My 98 impreza just pumps from the front washer tank to the back
There is a dip stick for the gear oil on the left side back towards the fire wall. It is hidden but you will see it.
Same place as you fill the front washer fluid. There is only one reservoir.
front or rear? the front is slightly higher and rear of the drain... the back has a cover you remove to drain the fluid and a fill on the front of the diff..
Unfortunatly I dont know the amount but I know you shouldnt put oil in your "auto transmission" you should be useing transmision fluid.
It doesn't have a drain plug. You either have to pull out of the fill hole with a vaccuum devise , or take the cover of to drain.
You have to pull the diff. cover and let it drain. Then replace the gasket. Put the diff cover back on then fill with gear oil. 75w-90 is recommended but 75w-140 could be used if you are towing a lot. Fill to about 5/8" below the fill plug on the top front of the diff. No you don't have to unbolt the cover. First check to see if you have a drain plug. It will be on the bottom of the differential housing. If you do it will save you money on a gasket.
I assume that you are referring to a manual transmission as you said oil and not fluid. On the side of the transmission, 1/2 way up, you should see a fill plug. Remove it and insert your little finger to the first joint. If you touch fluid or it runs out then it is ok. If not then fill to the edge.
Remove the 10 bolts that secure the differential cover, pry the cover off, the fluid will drain out, clean the old gasket sealant off of the cover & housing, apply a thin bead of RTV to the diff cover & bolt it back into place, use a criss-cross pattern to tighten the bolts back up, fill the diff through the fill hole on the diff cover, will take aprox 1.5 quarts, stop filling when fluid leaks out of the fill hole, replace fill plug.
You will need to remove the plate on the housing to drain it. There's a fill plug on the front side where the drive shaft hooks to it.
there should be a drain fill plug on the front your diff. Since you have the IFS probably the easierst way to get oil into it would be to use along piece of fuel line from the top of your engine to the fill plug and just fill it from under the hood rather fan fighting with the bottle underneith the truck.
Place a drain pan under the differential. Loosen the bolts, but don't take the diff cover completely off. Let the fluid drain into the drain pan. When it stops draining, take the diff cover off. Siphon out the remaining fluid from the bottom of the diff. Scrape off the remaining gasket. Place the new gasket on, with some RTV. Put the diff cover back on and tighten it. Remove the fill plug. Fill to the bottom of the fill plug. Replace the fill plug.