I have an 87 GL-Wagon and plan on changing out the rear diff fluid this weekend and was wondering what weight is recommened and how much? It is four wheel drive if that matters. Thanks for the help.

From the book:

 

Fluid recommendations

Use gear oil with API classification GL-5 for open differentials and GLS for limited slip differential. Viscosity should be:

 

*SAE 90-above 30 deg F

*SAE 85W-above 30 def F

*Sae 80W-below 0 def F

 

.........................................

 

A regular member of Ultimate Sub site suggested to remove the UPPER plug first prior to removing and draining the fluid from the bottom... the obvious point is if you can't get fill plug out and no oil in gear box..URSCREWED.

 

I took mine out....took 3/8 drive I think (didn't have metric that fix) and 3 Ft cheater bar... made a loup POP, when she came loose... thus... assure to do top first just in case.

 

Good luck.

I quess one question I have then is how would I tell whether I have an open diff or limited slip diff? I was reading in my manual as well and 75/90 covers the largest range of temps so would that be the best oil to put in the rear diff and manual tranny? If not what weight would you suggest for someone who lives in Washington State? I am just wanting to change out the diff and tranny this weekend. Thanks a lot for the help. Any other input would be appreciated.

If you look on the rear diff to the left of the filler plug you should see a foil sticker that has LSD in big letters. If you don't see the sticker just scrape off debri with a knife or a screwdriver.

I quess one question I have then is how would I tell whether I have an open diff or limited slip diff? I was reading in my manual as well and 75/90 covers the largest range of temps so would that be the best oil to put in the rear diff and manual tranny? If not what weight would you suggest for someone who lives in Washington State? I am just wanting to change out the diff and tranny this weekend. Thanks a lot for the help. Any other input would be appreciated.

Crown Loyale. So if it doesnt have LSD than it is just an open diff then? Just making sure I am understanding what you are saying.

yeah, thers a gold foil that will say LSD plainly. it will just be open if you dont see the foil. afaik, the LSD was found on RX, gl-10 with fulltime 4wd, and the occasional turbo coupe, like my parts car.

 

i used 75w90. as far as the actual labor, i used a 1/2" torque wrench AND my 3-ton jack to break the plugs loose.

to tell whether or not you have an LSD, in the event of a missing sticker, etc... jack up the rear of the car so both tires are off the ground. Spin one by hand. If the other moves the same direction, you have an LSD. If the other moves the opposite direction you have an open diff.

 

I've also heard the easiest way to crack open the fill/drain holes is to set your wrench on a jack, then jack the car up using the drain/fill plug. It *should* eventually break the plug loose.

 

One more thing... may be nice to invest in one of the pumper thingies that screw onto a quart of oil. Probably easier to do that than get tricky with funnels.

Thanks for all of the advice. So what weight oil would you guys recommend for the diff and tranny?

75w90 in all of mine.