rear differential fluid change issue

[gonzomech]

i have a 2002 V70XC w/168K miles. today i changed out my angle gear fluid ...for something that doesn't need changing (according to volvo) yuk! it was dark, thin, and smelled bad, however, there didn't seem to be any metal in it! i will change it again with the next oil change.

i then went to do the rear differential fluid and here is the issue...my fill plug is on the engine side of the differential. i can't seem to get a small enough tube in without hitting what seems to be the gearing or without having such a small tube that it is almost impossible to suck anything out. the good news was that the fluid didn't look nearly as bad as the angle gear's and it still had some of it's golden color!

can anyone suggest a good way to suck the diff. fluid out?

[Allen]

Park the car on a hill, it'll run out it's own.

[gonzomech]

sounds reasonable, but the fill plug is at the top of the diff....might need a pretty steep hill! the rear diff. only has a fill plug and not a drain correct? i couldn't seem to locate a drain plug.

[Allen]

sounds reasonable, but the fill plug is at the top of the diff....might need a pretty steep hill! the rear diff. only has a fill plug and not a drain correct? i couldn't seem to locate a drain plug.


Sounds like my 93 Isuzu Trooper. The front diff doesn't have a drain plug, but the transfer case and rear diff does. Doesn't make any sense.

[n00bkiller944]

Your going to have to get a mity vac or something similar to suck out/refill the differential...

[javaxc70]

It is possible to get that fluid out with a mightyvac pump (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39522&xcamp=google&utm_source=googlebase&utm_medium=cpc&zmam=33951326&zmas=12&zmac=112&zmap=39522), but it is definitely tight getting the tube in there to pull the fluid out. If your fluid is still golden in color, I would say save the change for another time. When I did mine with the mightyvac it took about 3X as long as the front due to the tight tolerances; the small hose kept binding and stopping the fluid from coming out. So, in short, you need mightvac or pneumatic pump to get that fluid out. Hope that helps! [thumbup]

[gonzomech]

thanks javaxc70! mightyvac, a hill, and some patience and i will tackle it when i change the bevel gear fluid again; ~4K miles.

another question...i noticed the crush washers on both the bevel and rear diff. fill plugs were copper, but the dealership gave me aluminum. are they copper because the bevel and rear diff. housings are steel...galvanic reaction and all?