So I decided to replace the rear differential fluid last week.
I'm sorry I don't have pictures...use your imagination.

I bought 80w90 gear oil and a pump.


So I open the drain plug and drain it into a glass jar. This is the worst, smelly, sticky stuff I have ever played with. Luckily, I had put newspaper down on the floor, anticipating some mess.

Edit: the drain plug had a about 1/8" of thick, gray grime around it: lots of tiny filings that thickened the grease and some larger filings attached to the magnet itself. It looked exactly like what I've seen from other replacement jobs.

Now, the drain plug was in really tight, way tighter than the 39 ftlbs the service manual requires.

The filling plug, however, was in even tighter. I could not get it out, for all my trying. I managed to strip the hex socket in the process. I swore it was giving...but no...it was stripping.

So now I'm worried. Not only have I stripped the socket, I've removed the fluid so I can't drive anywhere to have it removed.

So, I'm sitting there on the floor beneath the car, surveying my situation, looking at the pump.

And I wonder if I can fill it from the drain hole using the pump.

The nozzle, of course, doesn't fit snugly in the hole, so I folded a paper towel several times and poked a hole in the middle, fit the nozzle through the hole, and stuffed the end into the drain hole.

I pump a few times. The honey-colored gear oil flows up the tube and into the drain hole. Nothing comes out. I pump some more. Still, nothing comes out.

I filled the whole thing from the drain hole, putting in a little more than required anticipating some loss when I insert the drain plug.

Edit: the pump I used pumped one fluid ounce per pump. In addition, the gear oil bottles had a scale on the side so I could see how much I'd pumped. 1.48 qts is what the manual recommends.

Only a little came out when I made the switch, inserting the drain plug, due the oil's viscosity.

Now I just need to get someone to remove the filler plug and replace it...but that could wait another 60,000 miles, I suppose...

But the takeaway here: be sure you can remove the filler plug BEFORE you drain the fluid...

 

That's creative thinking. Did you keep track of the amount of fluid you pumped in? Btw, how many qts for a stock diff? Also, don't know about the stock diff, but my rmm 3.76 lsd uses 75 w 90.

 

that sucks man- I hope they can get it out for you when the time comes. How did you know how much to fill it up. don't you normally fill until level is flush with fill hole?

 

i think i put 1 1/2 quarts when i refilled mine... dang bro i hope u get the stripped screw situated

 

for rear differential it's about 1 and 1/2-3/4 quarts. all you do is pump the gear oil into the pumpkin and when the oil starts coming out, you're done. no need to fill it more because you can't, unless you want more oil on your floor

very easy. as for the drain plug, replace it when you do it again in four years. make sure no gear oil is leaking.

 

I also changed my differential oil on my 99 GS4, but I did what he recommended first.....I made SURE I could get the fill plug out BEFORE draining the old stuff out. I used the AMSOIL synthetic 75W90 gear oil. For the record, the factory Toyota fluid was really clean and honey colored. It actually did not need to be changed, but since I got the car recently, I wanted to be sure everything was done right.

It is also possible that he may have used a SAE allen wrench vice a METRIC tool to try to get the plug out. I am sure there are a lot of reasons a plug could get stripped out, but substituting one type for another usually causes stripping if enough force is used. I forgot to note what part of the counntry this was done in. Here in California, we have very little rust or basic corrosion under our cars, and my plugs always come out easy.

Of course the last person changing the fluid could have gotten a little exuberant with the wrench and over-torqued it.

Just my $.02

 

I changed my recently to synthetic as well. With 90,000 miles on it, the diff fluid was still golden too...

 

Did you clean your magnet when you changed the fluid? How much trash was on it. I had quite a bit of grime on mine. I will see how much is on the synthetic fluid next time I change it.

 

I purchased a Craftsman 10mm 3/8 drive hex socket - #42679 for this task. You just don't have the room for an allen wrench to work. Additionally, I used a 15 deg swivel extension with a 3/8 to 1/2 inch adapter and a double beam 1/2 drive torque wrench. The fill plug broke free at 80 Ft Lbs. while the drain plug was 65 Ft Lbs. I replaced the plug seals with copper the exact same size and thickness as the original steel compression type (PepBoys). Tightened to 45 Ft. Lbs. using a 3/8 ratchet click type torque wrench.