Changing Gearbox oil

[franjae]

Hi guys,

I finally did it....changed the gearbox and diff oil. I thought I'd share with you how I did it.

I did not have any chassis stand and the jacks were questionable. I did have a few soild limestone blocks lying around...110 X 350. Using smaller pieces of pavers as ramp, I mananged to drive the car up on these blocks, giving me room to slide underneath. So far so good.

I managed to remove both the fill and drain bolts easy enough. When I was ready to fill, I realised that the pump I bought was too tall to use and it did not fit the Redline bottles

Found a roll of new 13mm retic poly hose and decided to try using that with a funnel. I used a 90 degree elbow and this is place into the fill hole. I then poured the MT90 down the funnel from the engine bay and that worked a treat !!

The diff refill was pretty much the same, the hose when through the rear passenger wheel arch and once again it filled without a hitch. The fill plug wouldn't shift so I bashed the socket wrench using a rubber mallet to loosen it.

For those of you contemplating this oil change, DO IT. I can't believe how much difference it made to the gear changes. First to Second crunch is nearly all smoothed out! Gear changes are now so much more positive.

Cheers

franjae

[Andrew]

I've done it a that way on a couple of MX-5 now....quick and easy with no pumping required

[Craig]

Good to hear!

[Garry]

Make sure you loosen the fill plug BEFORE you undo the drain plug. It's not very helpful if you've drained out all the old oil but cant put any new oil in.

To get the oil level right the car needs to be on a level surface as you add oil to the gearbox/diff up until the oil starts running out of the fill hole. If the car isn't level all the old oil wont drain out and you could end up over or under filling with new oil.

I've used a piece of garden hose and a funnel several times, no need for any fancy 90 degree bends. It's considerably quicker and easier than a pump. It has the added advantage of being able to jack the car up to drain the oil then lower it back down so it's level to add the oil if you dont have the luxury of using a hoist.

Regular gearbox oil changes work wonders on the MX5 gearchange shift quality. I think the factory oil change intervals are to long. The gearchange quality will continue to improve for several hundred kilometres as the new oil works it's way through the gearbox internals.

[Regie]

any tips for getting the drain plug loose on the gearbox? ive got the car juacked up ready to go. The fill plug came loose easy but the drain plug looks as though it has silicone on the threads....i know the last gbox service was done by Mazda prolly by a 14yo first year...buggers.

[16bit]

Hi guys,

I finally did it....changed the gearbox and diff oil. I thought I'd share with you how I did it.

I did not have any chassis stand and the jacks were questionable. I did have a few soild limestone blocks lying around...110 X 350. Using smaller pieces of pavers as ramp, I mananged to drive the car up on these blocks, giving me room to slide underneath. So far so good.

I managed to remove both the fill and drain bolts easy enough. When I was ready to fill, I realised that the pump I bought was too tall to use and it did not fit the Redline bottles

Found a roll of new 13mm retic poly hose and decided to try using that with a funnel. I used a 90 degree elbow and this is place into the fill hole. I then poured the MT90 down the funnel from the engine bay and that worked a treat !!

The diff refill was pretty much the same, the hose when through the rear passenger wheel arch and once again it filled without a hitch. The fill plug wouldn't shift so I bashed the socket wrench using a rubber mallet to loosen it.

For those of you contemplating this oil change, DO IT. I can't believe how much difference it made to the gear changes. First to Second crunch is nearly all smoothed out! Gear changes are now so much more positive.

Cheers

franjae

I really wish i noticed this a few weeks ago. i got under the car with pump and all. Will certainly do this next time. also did the engine oil at the same time. what a fark around the oil filter is. I am soooo getting a relocation kit for the next time. I have changed the oil before but never the filter which is bad but after doing it slightly justified in an odd but lazy way.

[wun911]

If you cant get the fill plug undone and you have already drained out all the oil.

You can do a super dodgy and fill it fron the shifter turret but this only applies if you have a 6 spd.

I find that it takes exactly 2 quarts of MT 90 to fill my car.

[Regie]

If you cant get the fill plug undone and you have already drained out all the oil.

You can do a super dodgy and fill it fron the shifter turret but this only applies if you have a 6 spd.

I find that it takes exactly 2 quarts of MT 90 to fill my car.

ive got the fill plug undone....its the drain plug that i cant undo..its full of silicone in the thread

[wun911]

Oh didn't read properly my bad.

I think the drain bolt is a 24 mm bolt it should NOT have any silicone on it?!?!?

I usually use a breaker bar on it because I'm piss week and asian.

[Regie]

Oh didn't read properly my bad.

I think the drain bolt is a 24 mm bolt it should NOT have any silicone on it?!?!?

I usually use a breaker bar on it because I'm piss week and asian.

yeah i wouldnt have thought so.. i had a breaker bar on it and she still dont want to move.. might head down to the workshop and borrow a hoist for a hour..might make life a bit easier

[JBT]

No filter for the gearbox. Here is a link: http://www.miata.net/garage/trans/everything.html

Maybe you'd be best to take your car to a service centre.

[16bit]

the mazda guide says that the gear box should take 2L which is about 2 quarts i think (.9somthing L). and year no gearbox filter.

[Regie]

wow what a difference a new batch of oil makes in there. Got mine done today with full Synthetic...very nice shifting now!

[mr_rotary]

I've used a piece of garden hose and a funnel several times, no need for any fancy 90 degree bends.

Been there done that and find the garden hose & funnel more a pain in the backside with more going out than in.

I've invested in a couple of 1L 'Tom Thumb' pumps for gearboxes, diffs etc. Just hook the hose over the inlet and pump.
Clean, efficient and simple to use.

Available from Malz in WA and Autobarn elsewhere.
http://www.autobarn.com.au/products/15/203/235/

[wun911]

I have one as well its awsome....