Differential Fluid Question on 98 Avalon

[RStocker1]

Ok, so now I'm real confused. I have done my 3rd drain and refill of the Transmission fluid pan, and it now looks nice and red like it should. So I move to drain and refill the differential (since both this forum and the Chilton's book both say that the 98 has the separate differential fluid chamber), and lo and behold, no refill plug. At the spot where it should have been is the flat collar to seat the aluminum washer, but the hole is plugged. There is a drain plug where the book says it should be, but no refill plug. Fortunately, I looked for the refill plug before removing the drain plug.

My question is this: Is this telling me that my 98 has the shared transmission and differential fluid chamber (contrary to what I've read)?

[kegunder]

I have the same questions with my 2000. I believe I discovered that there are 2 drains, but only on filler. This was because I drained the main chamber and I didn't get the amount expected. Then I filled w/ 5 qts and my system was way too full. (I did cycle the trans. gears while parked as the manual states.)

[toyomoho]

The questions have come up before. Some trans have a shared fill point with the diff, others don’t. Have you looked around the backside of the differential housing between the firewall and housing? If you do not find a diff filling port, chances are the trans shares the same fill point.

When replacing the trans/diff fluid, the diff drain plug may need to be removed to drain its fluid.

When draining and refilling the trans keep in mind a certain portion of the fluid is retained in the torque converter. As such it is best to attempt to measure what drains out and refill with the same amount of fluid.

[RStocker1]

Originally Posted by toyomoho

...Some trans have a shared fill point with the diff, others don’t...

By shared fill point, do you mean the main fill tube at the front? This would fill BOTH chambers? I don't want to drain the diff until I'm sure I can refill it. I didn't see anything anywhere that looked like a fill plug.

[toyomoho]

The other locations to check are the top and sides of the diff housing. If you find nothing chances are the system has a single point refill for chambers. Again, the question has come up. This problem is some years of Avalon had this setup, others did not. Hence the confusion. The indicator is that there is no refill plug where it should be.

[RStocker1]

Originally Posted by toyomoho

The other locations to check are the top and sides of the diff housing. If you find nothing chances are the system has a single point refill for chambers...

The only thing I found even remotely close was a connector ON TOP of the diff housing. I dismissed it as a sensor, since there are 2 wires connecting to it. Toyota wouldn't make you remove that to fill the diff, would they?

[csaxon]

If the differential fill plug of a 5xx series trans is plugged, then it is serviced through the trans fill tube. They share the same fluid.

[toyomoho]

The sensor is most likely the speed sensor for the speedo, ECM, etc. Suggest when you drain all the fluid out getting some kind of quantity measurement. Then you can refill the same amount of fluid and do a finally check. Saves time and prevents overfilling.