Our SC400 has 220K miles. It's never had the diff fluid changed. Since I had just changed the diff fluid in my 300ZX, I decided to do all of the cars as I already had the marine pump ready with 75w90 synthetic.

However, upon pulling the filler plug (wanted to make sure I could get it off before trying to do the drain plug) diff fluid started dripping out. To my amazement, it is a light clear golden color. It looks brand new. How can this be????

I guess the next question is, should I go ahead and change it?

 

Ugly stuffs are down near the drain plug. For RX300, drain plugs have magnets to retain metal debris. If SC is similiar to RX, gear oil near the drain plug should be black with fine metal particles floating around.

 

I went ahead and changed it anyways since it was already up on the stands. The entire contents, about 1.75 quarts was entirely golden. The drain plug had a thin layer (maybe a milimeter) very fine iron coating the magnet. There were no larger particles.

It seems to me that Toyota must have been using a synthetic gear oil from the factory. I can't think of any other reason why it wouldn't have been burnt up by now.

 

BTW, does anyone know what the torque values are for the drain and fill plugs? I've torqued them to 20 ft-lbs based on the size of the bolt but would rather do it by the FSM which I don't have but should.

 

Thats totally awesome... and to think, we're recommended to change it out every 15K miles.

 

I just realized the carrier is iron and not aluminum, so my 20 ft-lb guess was based on a steel bolt in an aluminum threaded hole. So I went back out and retorqued to 35 ft-lbs. Hopefully this is close enough. Anyone know the real spec?

 

How strange, my '95 manual doesn't have any mileage recommendation for changing the diff fluid.

 

My differential is made of cast iron; where the plugs screw in. Torqued mine to 35 Ft Lbs, using the original crush washers.

 

I changed the differential oil in my GS300 at 85k and it looked pretty bad (compared to new oil). Also, the drain plug had a decent amount of metal on it. I replaced it with synthetic 75W90. And I intend on replacing it again soon to seen what the fluid looks like.

 

is it 1.75 qts in a 92 sc400 as well?

thanks

 

cool, thanks

 

Fill differentials from the fill hole until it barely starts to drip out. Clean the gunk left on the drain plug threads (if any), then quickly plug it and tighten...because many cars have plugs that are tapered, you have to watch out on this one.