mogley

This may sound like a stupid question but how do i change gearbox oil?

I have flicked through the manual and there is nothing in there about changing the gearbox oil and I really want to add some Motul to see if it makes my box a little slicker. Currently feels a little notchier than before.

auzoom

Open door, sit in drivers seat, insert key, start engine, drive to local service station, hand over keys, pay $$$

Joking aside, I have just changed from Motul to Royal Purple Syncromax as I had probs on the track and street. Street problems have gone but havn't had a chance to get to the track yet. Going to Sandown on the 23rd (?) October, will report back then.

Cheers

Andrew

takahashi

Get your mechanics to do it. LOL

Seriously, in your gear box there are 2 nuts. One on top of the other. So drain the old oil with the bottom plug. Put it back and squeeze the new oil to the top plug until it floods.

The thing is where to get that hand pump.

Yes it is a bloody dirty job, and I will pay people to do it. The fact that I don't own a hoist make sense of paying $40 for it.

ILIV48

I am actually having mine changed tomorrow. Was advised to throw in some Redline 75/140 for better protection during the coming long hot summer on the track

Damn that oil not cheap though

Gomez

Mogley, get some tube and a funnel. Jack the car and keep it level....easy if you have ramps. Feed the tube down to the gearbox via the engine compartment. Undo the two large plugs on the left hand side of the transmission....top one first. Drain the oil out. Replace the lower drain plug. Insert tube into upper fill port. Fill with two quarts of oil via the funnel and tube. Replace upper fill plug.

More here (and elsewhere).....search is your friend.

https://www.rx8club.com/australia-new-zealand-forum-37/improved-shift-action-read-38942/

RXVIII

Could have a look at these

http://www.hi-impact.org/ryang/modify/rx8_fluids/rx8_fluids.html

https://www.rx8club.com/showthread.php?t=35115&highlight=box

takahashi

75/140 is lightweight shock proof or the other one?

the normal numbered one is for LSD I thought. But I guess gear oil = diff oil

takahashi

BEFORE

ILIV48

It's the Lightweight Shockproof Gear Oil.

I have heard a few people say it is not designed for Syncro transmissions including Redline but my supplier who has been in the business of oils for cars for a very long time especially for performance and race cars said that redline put that their because they cannot trial the product in all gear boxes out there so they play the safe game. The main issue with it and that has been stated by Redline themselves is it is not recommended for transmissions that use small pumps and lines and can clog these because of the way this oil is attracted to metal.

He says in transmissions that do not pump the oil around like the MX5 the Lightweight shockproof is fantastic and has no trouble with the Syncro's. Everyone I know respects him very much so I decided to trust him and give it a go. If it does not feel good after it's in then I will just replace it!

timbo

OK, call me a wimp, but I reckon gear oil changes are the job of a good service centre. That stuff stinks, and the smell persists, so you have to be very careful not to spill any on you, the car, or your garage floor. I think I paid around $70 for my guy to do the diff and gearbox. I would have been happy to pay twice that

mogley

People don't seem to really recommend doing the whole diff/gearbox oil change thing because there is no noticeable improvement.

Maybe I will just save my pennies for elsewhere. :0

Gomez

takahashi

When it is old - however. Need a change.

To what oil it is then debatable. I think Mazda overcharges everything they use, including the rotary engine oil

Revolver

I appreciate this is 'how' rather than 'why' but I'm yet to be convinced as to the correct answer on the latter.

For regular trackies I can see the force in changing it with more frequency than manufacturer recommendations and I suppose stuff with racy names like Royal Purple and Redline will attract a following but, to parrot Timbo's regular mantra, is there any hard evidence that normal street drivers gain any benefit from changing to another product or changing it earlier than recommended???

Not being critical here - just curious.

auzoom

Hard evidence? Dont think so.
Benefits? Also dont think so. In fact I would bet 10 bucks on it. Come get it people

ILIV48

Well I have now had the change done to Redline Lightweight shockproof and I can say there certainly is a difference in feel to the car. Even the Mazda service mechanic commented to me when I picked up the car that he noticed an instant difference compared to the pre service inspection drive.

It just feels smoother while accerating and also less gearbox clattering at low speeds & idling with the clutch out. The shifting feel is also a lot smoother now which is a big bonus as it had a tendency to be very stiff at times.

I am very happy with the results!

auzoom

You know what I have noticed since going from Motul to Syncromax...

When I accelerate up gears at high RPM, the car actually takes off rather than bogs down, literally leaps forward as if I had accellerated before releasing clutch..I quite like it.

Andrew

takahashi

It will get better when the oil have time to "settle" in. Mine now is AOK. Await the track day and I will post my results.

Kall,

Gear = Redline MT90 or Lightweight shockproof.
Diff = Redline 80W140 (since you go drifting)
Brake = Motul RBF 600.

takahashi

Not just regular trackies.

Just going to track twice will do it.

Mine oil changed before 2 X Winton and has turned black, have some funny oil streaks in it and fine metal flakes. There are only 2000km between change.