Changing the gearbox oil (FD3S)

[Wav]

Hi Guys,

Right I have a few moments free so I will try and do a quick guide on how to change the gearbox oil. For this case it is a 3rd gen. RX-7 (FD3S), but I don't think it differs too much for the 2nd gen and maybe only a little for the 1st.

Again what I am writing is simply what I did and gained good results from doing so, but this thread is only a guide and follow it with care as I take no responsibility for you getting it wrong:rolleyes: ;)


I used redline MT90 fully synth gear oil and bought it from C&R enterprises in Nottingham (VW Specialists), but Demon Tweaks also sell this stuff. 3 quarts is fine as I think the box holds something like just over 2.5qtz.

Please enjoy,

Paul:)

[Wav]

Ok first thing is first. Get the car jacked up on level ground. I used 4 axle stands, one at either corner of the car to get is completely off the ground and level. (N.B. Front wheel is off because I changed the ABS sensor at same time)

[Wav]

Now it is important to remove the 2 filler plugs before removing the drain plug. This makes sure that the filler plugs are not rusted in place so that you can actually put fluid in after you take it out:rolleyes: :D If you look at the pic the top left one is the filler plug, the right vertical middle hole is the level and the bottom nut is the drain plug.

To remove the fill plugs i used an allen key, but the proper tool should be a star key of the correct size. The check plug simply required a spanner of the correct diameter.

[Wav]

Pic.

[Wav]

Drain Old Fluid. I think it is a 24mm socket, you will also need a suitable container to catch the nasty smelly green gunk in!

[Wav]

Draining old fluid.

[Wav]

Clean up the magnetic gearbox sump plug along with the other plugs.

[Wav]

Once all the old fluid is fully out of your gearbox and you've cleaned up the threads etc then you'll be ready to put your new fluid in. So first thing is to remember to put back in and torque up your drain plug, a new alu washer would be advised here.

So now onto the clever bit, mazda designed the fill neck for the gearbox in silly place so you can't simply pour new fluid in as the transmission tunnel gets in the way. There are a number of ways to do this, eg. using a funnel and tubing going from the engine bay into the filler neck. But I decided on an alternate method, which doesn't take forever and is extremely clean...

What you need:

Std one man pressure style Brake bleed kit (halfrauds sell em for about 15quid)

1-2 metre length of flexible tubing with approx. 5mm inner diameter bore.

Pic below shows unmodified brake bleed kit

Here's

[Wav]

Now the problem with a std brake bleed kit is that it is meant to work in a fully sealed environment so the white tube doesn't need to go all the way to the bottom of the bottle.

So now you need to remove the white tube and insert your tube in the hole and push it all the way down to the bottom of the bottle. The tube should be a tight fit i.e. air tight, if not wrap some insulation tape around it to get it so it is a tight fit, if the tube is too big, go and find a better fitting one or if you don't mind ruining your bleed kit then drill out the hole to suit the pipe.

Pic below of modified brake bleed kit:-

[Wav]

Once satisfied that your contraption will not leak. Put the free end of your pipe in the filler hole of the gearbox, secure it in place using insulation tape so that it won't fall out by accident.

Now fill the bottle with fresh gearbox oil and tighten lid, attach the valve to either a bike tyre or car tyre and just let the kit do the rest. Before you know it the bottle will have drained and simply take off the pressure feed refil the bottle and repeat.

[Wav]

Keep filling her until you're roughly at 2.5quarts then watch the check hole like a hawk. Once the check hole starts to overspill, you're full. Take the pipe out, clean up the holes and replace the plugs.

Jack the car back down, check for leaks, then go for a drive and feel the difference new fluid makes:cool

Thanks for reading,

Paul:)

[Den]

Good write up paul and it is the same for an fc. I took the more awkward route of a using a long pipe and funnel as i didnt have a pump of any kind at hand.

[Ric]

I took a much less complicated route... I got Steve @ DS to do it for me!! ;)

I also got my diff oil changed at the same time and I would recommend it. My [old] gearbox oil wasn't in too bad condition although it benefited from the change but the diff oil was disgusting. I suspect that it's one of those items that often gets missed out on services as people forget about it.

[Ricco_04]

Excellant post, Cheers. :wave

[Jake]

Just found this old post doing a search. Could this be made a sticky please?

[Donato]

Done.

Paul you should bring out your own workshop manual mate! you could make a fortune! :D

[Andrew Harper]

Used a fluid transfer tube to do mine (the type used to take petrol from one car or tank to another).

Tubing was a bit too long but worked a treat, and no mess.

[sparkgap]

Thanks, last time I did it, I siphoned it in and it took about 3 hours though a 5mm ID tube!