Differential Filler Plug

I seem to recall there being a little VENT (approx 1/4" pipe thread) on the top of the differential which you could unscrew and then add ATF slowly. Check with your dealer for the capacity as the amount varies depending on which engine you have. Once you get at least a quart in there, I would head directly for a garage to get that filler plug removed so you can get an accurate filling.

If this a 90 V-6 Auto, There should be a plug approx. 4-6" above the drain plug. Need to insert small line and feed the fluid till it starts coming out the hole. should take about 0.75 to 1 qt. of ATF fluild. Hard part is coming up with the hose and funnel or other means of feeding the line with fluid. You might be able to find a feeding tube for the autoparts that connect to the ATF container directly.

Perhaps you missed the salient point. The OP cannot get the filler plug OUT of the differential cover.

differential box? Would the fluid in the transmission flow into the differential box somehow?

Thanks for your help, Philip. You are absolutely right.There is indeed a breathing valve at the top of the differential box. In fact, after removing the intake hose, it's much easier to fill through this vent than the filler hole. I slowly put in fluid to the capacity specified in the manual (1.7 qt.). I'm not sure I'd even bother to remove the filler plug at a Shop. Most shops wouldn't even do something like this. Besides, this car is too old (220K) and it would probably be the last time of differential fluid change.

Thanks again!

ZR

MAKE SURE you read 1.7 QUARTS and not 1.7 PINTS. Easy oversight.

I just double checked. It's indeed 1.7 qt. I live in US and there is no PINTS in the manual.

ZR

Just curious, what trannie do you have?

I had mine serviced last week and got into a discussion about the whole trannie/differential/capacities/fluid type thing.

There is a transition period during the early / mid 1990's where some of Toyota's front wheel drive four speed autos had a separate reservoir of ATF lubricating the final drive while in others the ATF flowed freely between the final drive and the rest of the automatic transmission. On the latter, there is no *filler* plug at the rear of the transmission.

Yeah, that was the conclusion we'd reached.

There was one question, though.... Did Toyota have only one AOD tranny in '93?

The guy who runs the service shop has a 4 cylinder w/AOD and his doesn't have a separate diff reservoir. He said it was the same year as mine [which is a V6, btw], but I didn't bother looking at it.

I know it's not unheard of to switch something like this in the middle of a model year.... just wondering.

Yeah, that was the conclusion we'd reached.

There was one question, though.... The original poster said the capacity for his differential is 1.7 quarts. I know mine -- for a V6 AOD -- is 0.8 quarts. Am I correct in saying there are 2 automatic trannies, one for the 4 cyl and one for the V6? [And I suppose the original poster has a 4 cylinder.]

I don't know how to differentiate trannies, but mine is a 90 Camry with 4 Cylinder engine. It has what looks like a pretty "big" differential box and the capacity is 1.7 qt. On the other hand, my 2000 6 Cyl Sienna also has a separate differential box with only 0.7 qt. capacity.

Call dealer for correct capacity of diff or consult a service manual. Overfilling might cause problems.

Are you saying the capacity listed in the Manual might be inaccurate?

I heard a lot about the danger of overfilling (including oil, trannie and diff). But I have not seen an convincing explanation why a slight overfill would cause problem. One explanation is that overfill would increase pressure and damage internal parts. But that doesn't make any sense. The pressure is created by some type of pump. I don't see why the pump would increase pressure just because you have more fluid in the reservoir. Besides the reservoirs have some type of vents or not pressurized.

Of course, it'll cause problem if some internal parts are not supposed to have oil/fluid and are not sealed off. Are there any such internal systems?

Another thing is the oil/fluid may overflow out through vents/holes when hot.

Well, I finally found my manual [1992-1996] and it lists the capacity for a 4 cyl auto differential as 1.7 quarts.

Whew!

It is1.7 quarts . I changed mine (96 Camry) yesterday and that's how much I put in :-)...or as near to 1.7 as I can tell by the marks on the plastic bottle.

Ken Day

Yeah, that'd thrown me off when I first saw it because I know my V6 differential takes 0.7 quarts.