I was wandering what is the "EXACT" quarts does our FD Differential takes.??
I've been searching and reading, and found all kinds of results. I see 1.3 qt, 1.4 qt, to 2 qt of 75w90 gear oil. And I also read up on some threads explaining to just fill the differential untill it overflows from where you pour the gear oil into, then that means it's good to go????
So what is the "EXACT" QUART the Differential shall takes.

 

Per the shop manual, the rear diff takes1.38 US quarts:

 

Owner’s manual says 1.4qt, so I just stick to that. I'm sure the Mazda engineers didn't just pull that number out of their ***. It seems like over filling it could cause problems not as bad as under filling it I guess, but I'm not really sure. And the transmission is 2.6qt so it comes out to be a nice 4 qt of fluid I have to buy so none is wasted.

 

okay thanks guys. I guess I'mma have to try 1.4 qt. for now.

 

Where are you going to buy .4 qts????

What, are you going to measure out excatly 1.4 qts & not a drop more?

You can't "over fill" it.........

You only have two plugs to choose from.

One is lower & will drain all the oil out.

The other is higher & will only allow so much fluid to be added before it flows out.

The quetion you need to ask is how much fluid do I need to buy to service my diff.

The answer is 2 qts.

 

Yep. Just fill until it can't take any more and it comes out of the fill hole. Same procedure for filling the tranny. I believe it should be documented in the shop manual - that is the correct way to do it.

Dale

 

Does the car have to be completely level.? or can I just jack one side of the car and fill it in like that until I see it overflow out.

Anyways, thanks. That's more than enough info. now.

 

[QUOTE=z28_SS]Does the car have to be completely level.? or can I just jack one side of the car and fill it in like that until I see it overflow out.[QUOTE]

Are you serious????

If you have to ask, you shouldn't be doing this job by yourself.

Think about it. Do you check your engine oil when your parked on a hill?

Level the car on jack stands (4 of them)

 

Yes I do... Result was really close too.

 

I usually put the car on 4 jackstands just to make sure. The difference is pretty minor, maybe only a few ounces, but that's my attention to detail .

Dale

 

Actually I just changed my diff oil this past weekend and this is how I did it:
1. Park car on a relatively level surface( I did it in my carport).
2. Jacked up rear end of car ( I did it with STOCK car jack on the passenger side).
3. Remove top bolt of diff. Just to be sure that it can come off easily. You'd be screwed if you drained the diff first and then realized the fill bolt won't come off.
4. Remove drain bolt and drain diff.
5. Lower car to allow as much of the gear oil to drain as possible. I just added a few ounces of new oil to get some of the gunk that was left over out and then lowered the car so it was "level".
6. Jack the rear end back up again.
7. Reinstall drain plug
8. Add new gear oil( I used Mobil 1 cause nothing else was availible locally) into the fill plug, until the oil starts comming out of the fill plug.
9. Lower car till it's level, watch the new oil flow out until it stops.
10. Jack car back up and reinstall fill plug.

Yeah, my way you have to jack the car up and down several times, but if you don't have 4 stands handy, it's the way to go and you're using the car to tell you when the diff is full. I would have gone with RP or NEO diff oil, but they weren't availible locally. But even with using just Mobil 1, I noticed a considerable difference in how the rear end feels while driving. BTW, the fill and drain bolts are 24MM and you can do them both with a deep well 24MM socket. It's a cheap and easy way to pamper your FD.