Help with changing gear oil

[WankelsRevenge]

So I got lucky the other day and a guy I work with gave me like 5qts of amsoil 80/90 full synthetic gear oil for my tranny. My question is in changing it does my car need to be level? All I have are some ramps I can pull it up on and dont know if this will effect the process at all. Also any tips on refilling it? Ive heard you can just pour the new oil into the hole where the shifter mounts but Ive never tried it before.

[Pete_89T2]

Yes the car needs to be level to refill the tranny properly. Pouring it in via the shifter will take forever and probably make a big mess. Recommend you pick up one of those hand operated fluid transfer pumps to move the oil from its container into the fill plug hole.

[RETed]

First of all, is the gear oil you got "GL-4" rated?
GL-4 is specific for (manual) transmissions with brass synchronizers.
There is gear oil that are "GL-5" rated that is not designed for our transmissions.
The GL-5 does not supercede the GL-4 rating, except in load bearing testing.
Sulfates are typically used to increase load rating, but the same sulfates can eat the transmission brass synchronizers.
Please read the gear oil bottle labels to confirm this.

Typically, the shifter extension housing is empty from the factory; Mazda does not fill them up with gear oil.
There are two other sections in front of the shifter extension housing that house most of the transmission gear and internals that need the trans fluid.
The sections are only connected by small passages at the top of the transmission.
This means to get trans fluid from the shifter extension housing to both gear sections, you need to fill all of them with trans fluid.
This will use slightly more than the factory spec 2.6 liters(?) of fluid.
(We - in the U.S. - typically get this stuff in quart bottles, and you need at least 3 quart bottles anyways, so this isn't that big of a deal.)
Here's the more immediate problem...
Since everything is now filled, your shifter boots better be in good shape, or else it leaks out from the shifter lever.
This is why Mazda doesn't fill the rear, shifter extension housing in the first place.

Although this is usually harder and messier, I'd recommend using a mechanics syringe to fill the trans from underneath.
Just fill the front two transmission sections as described in the FSM.


-Ted

[vrracing]

Page J2-8 of the S5 FSM shows the procedure. I didnt know about the GL4 vs GL5 info that RETed shared so that's helpful.

The key I have found is that you need to remove both plugs on the side of the tranny (labeled C & D in the FSM). You pump fluid into the top hole (C) until fluid comes out the lower hole (D). If you leave D in and fill to the bottom of C, gear oil will slosh out of the vent onto the exhaust. Burnt gear oil doesn't smell like bacon!

[infernosg]

Best if the engine is level.

As for proper filling instructions: http://wright-here.net/files/manuals/1989%20RX-7%20FSM/J1_Manual_Transmission_NA.pdf

Transmission: Page 8 (J1-7)
Extension housing: Page 47 (J1-46)

Assuming this is for a N/A transmission.

[WankelsRevenge]

I think I have GL5, but the online manual said you could use either 4or5. The main reason Im doing this is my 2nd and 3rd gear schrynos are basically shot and I was told by a couple people changeing into a better gear oil could help them shift into gear better.

[RETed]

I think I have GL5, but the online manual said you could use either 4or5. The main reason Im doing this is my 2nd and 3rd gear schrynos are basically shot and I was told by a couple people changeing into a better gear oil could help them shift into gear better.

Be careful with the GL-5...
Look at the label and check to see if it says something like: "safe for modern synchromesh transmissions"
Else, smell the stuff!
Sulfates is going to stink like rotten eggs and burn your nose.
Gear oil without the sulfates don't smell like that.

If your synchros are already on their way out, old trick is to run heavier gear oil...
Running the same (or close) viscosity oil is most likely not going to help at all.
Since the recommend oil is (I think) 75W90, go heavier...like add some 85W140?
The heavier oil just makes everything work slower, so this helps the gear changes and failing synchros.


-Ted

[t_g_farrell]

I've also heard of folks mixing a 50/50 blend of auto tranny oil and gear oil for helping out
old trannys. Seems to work but not sure why.

[vrracing]

In the MR2 turbo transaxles, when the synchros are wearing using Redline Lightweight Shockproof (http://www.redlineoil.com/product.aspx?pid=43&pcid=8)works very well. Getting into 2nd and 3rd was notchy and putting the Shockproof in was like magic. The tranny shifted beautifully.

It's pretty expensive (3qts will cost $45) but if your free stuff doesnt work it might be worth a shot. Cheaper than a new (used) tranny and easier than pulling that mutha! I don't know if the Shockproof meets RETed's GL standard but the Toyota was from the same era as the FC. Of course it could destroy your tranny. You'll have to decide if yours is far enough gone that it is worth taking a shot. As always up to you.

[WankelsRevenge]

Well Im already planning on getting a new trans, Im just waiting for a friend to be available so I can pick it up. Ive heard good things about the amsoil stuff I have so I might give it a try in the meantime, though right now I dont have a way to get my car level and be able to drain the trans.

[chibikougan]

If it is the SEVERE GEAR full synthetic you are good to go. If you use it in your Differential and its a LSD get a bottle of slip lock and put that in before you add the lube.

http://www.amsoil.com/shop/by-product/gear-lube/slip-lock-gear-oil-additive/

I run amsoil in all my rigs

[chibikougan]

This is a cheap pump that fits their large or quart containers

http://www.amsoil.com/shop/by-product/garage-accessories/bottle-hand-pump/

[Garfinkles Motor Works]

Invest in a floor jack and four jack stands,or split the cost with a friend if you do not have a place to store and use them and the friend does .

[t_g_farrell]

This is a cheap pump that fits their large or quart containers

http://www.amsoil.com/shop/by-product/garage-accessories/bottle-hand-pump/

+1, mine looks a lot like that and it will fit a lot of plastic 1 gallon or 1/2 gallon
jugs.

[Pete_89T2]

This is a cheap pump that fits their large or quart containers

http://www.amsoil.com/shop/by-product/garage-accessories/bottle-hand-pump/

Any decent auto parts shop will have a similar product. I believe the one I got was branded as "Sta-Lube", and I picked it up for a few bucks at Pep Boys.

Also, Motive Products now makes a product which is just like their pressure brake bleeders that is modified with a valve/nozzle to fill trannys & diffs. Pricey, but much better than a hand pump.

The Motive design is so simple that I might just pick up a cheap tank sprayer and try to adapt it to the tranny/diff lube dispenser role.