Rear diff Lube

I have a little over 2qts in my diff that is from filling it on a chair before putting it in the car..

I plan to check the compacity later next spring before I start the car up..

[rx7 FC TII]

i used redline a few months ago. couldnt really tell you if theres a difference or not yet. i havent changed it and prolly wont need to for a good while.

[Trout2]

I started with AMSOIL in my FD's trans and rear then switched to NEO. Can't say any difference for differential performance but the NEO resulted in smoother shifting.

Jack

[prrex4ever]

I too have used both redline and neo in my fc and fd and neo seems to work better for me.

[RETed]

This thread is at least 3 months old.
Why are people talking about shifting when the OP was just talking about the rear diff???


-Ted

[prrex4ever]

Not being confrontational but, 1- share and exchange information, experiences and information with fellow rotary lovers. 2- keep site active, current and alive. 3- meet fellow car enthusiasts with similar likes and taste in automobiles, ie; network. You sir are right, my first post on this subject was about transmission shifting (totally irrelevant). My bad! My second post is about differentials. I hope that is ok with you, peace.

[pachizeron]

I have heard that redline is good but I haven't tried it yet. Anyway, why don't you try using costal 80w-90. Its very good.

[Max777]

actually, the recomended fluid is 75W-90 NOT 80W-90... there is a factory service bulletin that says to switch to the 75W grade if the customer complains of hard shifting in cold weather. also, there is a Redline Gear oil for hypoid gears, ie: differentials, and a Redline MTF, different grades of both. There is a specific Redline MTF that is geared for Mazda Transmissions. another thign to consider is the use of GL4 gear oil. From some reading I did, it seems like the GL4 stuff seems to work smoother than the GL5 stuff because the GL5 fluid is too slippery to properly engage the synchronizer blocking rings...(the brass/copper looking things that are part of the synchronizer assembly in your transmission)

Here's a pic:



MT-90 75W90 GL-4 Gear Oil is what you want to use for the trans, not recomended for hypoid gears.

75W90 GL-5 Gear Oil is what you want to use for the diff.


Personally, I could not afford Redline right now, so I used GL4 compatible Coastal Gear oil, 75W-90 grade, this stuff is good for a daily, and cheap if you want to flush out your drivetrain before putting in expensive stuff.

http://www.redlineoil.com/Products.aspx?pcid=7


There, bam... I feel like a fuckin expert on redline oils now, they should pay me for this!

[Whizbang]

hmm that is interesting.

[Max777]

I dunno, all of it was fairly easy to find, Google search, evil forum search, and some light reading, calling people, etc...

I would just recommend going with a good synthetic, like Redline, Neo, or Amsoil... in a street car, I think any will be better than the average stuff on the shelf.

Oh, and All Data: http://www.alldata.tsb.com/home/ rocks when you dont have to pay for it!

[Whizbang]

once the FB stops leaking fluid everywhere, ill actually treat it to some nicer fluid in the differential. Especially considering the 4.78 gears and the tighter preload im using. Im still running synthetic but i have a rather nasty leak...

...as for my transmission, reverse is fooked, so i have to replace it soon enough anyway.

[Max777]

The rumor is that if you overfill your trans, the seals will leak like a mofo, so make sure not to put too much in.

http://www.aaroncake.net/rx-7/transfluid.htm

[Whizbang]

i havent overfilled anything. i actually havent really touched the transmission either. but the diff has a leak at the mating area of the 3rd member and the axle housing

[rx4ur7]

I have used SWEPCO in transmissions and rears since 1986 in all client and race cars. Never had a gear oil related failure in anything. Never had any oil on the ground issues like most synthetics.
I believe I posted else where on the site my experiences and other relavent information out this amazing product. For a street vehicle you will probably never have to change your oil again since SWEPCO's recommended service time for change is 10,000 hrs. They offer an oil analysis for their product recommended test time is every 3 years.
To check out more go to www.swepcousa.com.

[eyecandy]

I am sure I am late too this but I really like Neo Synthetic oil. I have used it my RX7 and IS300. I know NEO is heavily involved with the motorsports world, and Carbonetic now uses there oil for there LSDs.