Unless I'm misunderstanding what you mean by differential oil, these cars don't have a differential. The rear wheels are what is called independent suspension with each wheel attached to a single point on the car.

They are front wheel drive with a trans-axle. The lubricating fluid is the transmission fluid. The axle is then connected to the wheels by a CV joint which has a heavy grease for lubrication.

 

From what I have read, Toyota Corolla From 1990 -1992 that have a three speed automatic transmission. Have a second place to put oil in the rear of the transmission. This place as far as I can glean is called the differential. I very well may be mistaken. Now four speed automatic transmissions in the same years same make/model do not have this "hidden" oil spot. The difference between a three and a four speed is the over drive which I do not have.

 

The 1992 4afe engine trans-axle is also called the rear differential on these cars since it is behind the transmission but attached to it as a complete unit. This shouldn'be confused with the rear differentials that are part of the rear axle on rear wheel drive cars. The other variant is rear diffs on all-wheel/all-trac drives.

In the front engine compartment there is the transmission dip-stick and on the bottom of the transmission is the transmission pan that has a drain plug. The transmission filter can be changed by dropping the transmission pan and replacing the filter and gasket.

As for the rear diff on this car it is a separate compartment and it doesn't share fluids with the transmission although it uses the same fluid in the rear diff. There is no filter for the rear diff. The rear diff contains a drain plug which is on the bottom of the rear diff housing. There is no rear diff pan and gasket although the back cover of this rear diff contains a fill plug (17mm) and uses fipg gasket material. You can find this fill plug by raising the car and putting a flashlight on the rear diff cover above the cross member but to the left of the rear engine mount and the bolt is in the center of this cover. There is no rear diff dip-stick. To check this fluid one unbolts the fill plug and then sticks a finger into the hole to see if fluid goes on your finger. One uses a hand pump from walmart to move the fluid from the bottle through the clear pump hose and thru this hole until it starts coming out. It is considered filled when the fluid is at the bottom of the fill hole before it leaks out. Then tighten down like the oil fill plug to 17-18 ft-lbs.

Note: if the fluid is low, it needs to be filled since not lubricating the diff gear inside that the axles spin off of, means you can destroy the rear diff resulting in you either replacing the transmission or rebuilding the rear diff. Most mechanics don't know that this toyota's transmission is two compartments and aren't shared: the transmission and the rear diff.

The rear diff fluid leaks out by either a bad drivers and/or passenger axle seal that is damaged or the result of getting old, or it can leak out through the o-ring at the top of the rear diff where the speedometer cable plugs in. One doesn't have to change the rear diff back cover fipg material and is pretty much a permanent seal and doesn't leak.

 

I've attached the page from my Chilton manual that has pictures to go with swegmike's check/fill procedure.


I saw this in the manual, but I thought it was just for AWD equipped cars.

 

Thanks everyone for your help! Okay now what oil should I use? From more reading i think dexron but could be mistaken. Now the same oil can be used for both the rear differential and the transmission?

Okay reason I started researching was becuase my transmission was making noises and shimming to gear while driving. I figured low fluid but it was just changed. No leak ether fluid is on level as far as i can tell. If the rear diff oil was low or empty would it cause the same symptoms of tranny proplems as if the front was low?

The links from the cliton manual and the attachment are non accessable!

What spurred it was going up a hill in torrential rain and to have the tranny slip i think. I was accelerating up. hill and bam my car learched backwards dropped ten miles an hour. It whined heavly then i let of the gas. Then the motor shifted and got back up to speed.
i got home with out further incident.

 

The differential, transmission and power steering pump all use Dexron II. They don't make this anymore, so you have to find something that says it's compatible, like Dexron III.

I believe there may be different sizes for the fill plug, or they changed it for the 7th gens. Mine has/had a metal ring gasket on the fill and drain plug. It's hard to find a wrench that will reach between the differential and firewall to loosen the fill plug. Be sure you can loosen the fill plug before draining the fluid, or else you won't be able to refill.

You can use a funnel with a hose attached and drop it down from above to refill (if you don't have the hand pump type).

 

If it is a hex head like an allen wrench I have used a chop saw to shorten one up or as was the case on the last one where I didn't want to chop up my special order 15mm wrench, I bought a bolt with the correct size head and double nutted it. That works brilliantly as you can put a gear wrench on it and crank from any position.

 

Toyota only put hex type allen bolts on the drain plugs for trans/diff. The diff fill plug is a regular bolt head.

 

You can also use dextron VI in the transmission and front differential.
On gen2 camrys one can use transmission fluid in the power steering, but on
the 1992 4afe, it calls for regular power steering fluid.

 

It should say on the power steering reservoir cap what fluid it takes. As far as I know all 6th and 7th gen Corollas, the cap says Dexron II.

 

I remember that the task of changing the differential oil was the subject of an exotically detailed, step-by-step PHOTO SERIES posted here about 6 or 7 weeks ago.

It was so good you could have been cross-eyed, babbling, and have a big wet spot on the front of your trousers hanging out at the bus depot, and still do it yourself for like $15 and a few hand tools.

Pretty sure someone is going to score you the link in an hour or two.

I'm very close to being one of those idiots and did not know it was a seperate deal from the regular transmission oil.

I'm going to be changing my differential oil in the next month or so, I believe.

 

It should be in the stickies.