Oil change on NC Powershift Automatic Transmission Gearbox

Technical Area Engine, Transmission, Exhaust etc
2

Hi all.

Well I’ve searched and searched on here and can’t find a single post about changing the oil on the powershift auto box. Does anyone know of a guide - especially if there’s a filter to change and what the refill and level procedure is?

Cheers,

 

Shaun

3

There are lots of owners of those cars on miata.net

I would register there and ask the question.

4

If the oil on the ATF dipstick (if you can find it) is nice and clean and red then it doesn’t need a change. 

If there are no leaks on the plumbing to the ATF cooler and no drips from the AT oil pan, and the level is correct, then it should be OK.  Just have another look in a few months time…

If it’s looking burnt and doesn’t smell too good, then let yourself in for the nightmare.

There is a drain plug on the pan, but refill is via the dipstick tube!  There is a filter of sorts inside the AT, more of a strainer than a filter.

Mellens has some NC Auto details on overhaul, but nothing on servicing and the external connections, and you don’t want to get into dismantling it! The powershift will not be all that much different, just a bit more clever in how it talks to the solenoids.

http://www.mellens.net/mazda/Mazda-Miata-2006-2007/auto_trans_overhaul.pdf

 EDIT

Here is a link to the NB transmission servicing, it is similar in principle, useful on checking levels etc

http://www.mellens.net/mazda/Mazda-Miata-2005/auto_transmission_service_removal.pdf

5

There is no service interval for the ATF. The refill procedure is very specific there is a connector under the dash that has to be grounded with the engine running, when the oil temperature is correct the light on instrument cluster flashes, you then remove a drain cock from the drain plug and allow the oil to find it’s own level. Refil is through a plug on the side of the transmission.

I the box isn’t giving any trouble, I’d leave it.

6

Thanks for the replies so far.

I’m not sure what you mean by ‘remove a drain cock from the drain plug’??

The drain plug is quite normal so not understanding what you’re telling me.

Cheers Shaun

7

Sorry, does it have 2 plugs in the oil pan? Ones a drain, the other is a level plug. I thought I’d seen drain plugs with integral level plugs if you get what I mean.

8

Yes it has 2 plugs in the sump and a fill(?) plug in the side. Photos should show you:

 

9

The photos are useful.  Going by the Mellen’s drawings I mentioned before which are a good match to your photo:

the plug underneath at the back of the sump is the drain plug. (Fig 2 item 1)

the filler plug  (Fig 1 item 5) is out of sight, but not far away up on the main casting to the right of that plastic electrical connector. 

the plug partway along the side underneath the sump is the 'overflow ’ plug (Fig 2 item 3). 

Essentially it is as Robbie said. 

There is another drain plug (Fig 1 item 7) but this is in the pump system and should not be played with.

Bear in mind all the fluid tests etc have to be done at the correct temperatures.  You also need new seals on the plugs if you disturb them.

 

Good luck!

10

Thank you Richard

11

Hi Robbie

Can you help me locate the connector under the dash you refer to above please?

 

Cheers, Shaun

 

12

I’ll find the exact location tomorrow evening and report back.

13

Thank you

14

The check connector is taped to the wiring loom for the transmission control module which is located to the left of the steering column. The TCM is secured to a bracket with 2 nuts and I think has 2 block connectors going to it. The check connector has 2 wires (Green/Black & Black) which you have to short together, shift the transmission from N to D in less than 1.5 second intervals repeatedly until the AT warning light illuminates for 2 seconds and then turns off. Allow the engine to idle until the AT light turns back on then remove the overflow plug and allow the oil to drain to find it’s own level. If the AT light starts blinking the ATF has got to hot, allow it to cool and start the procedure again. If no fluid drains from the overflow plug, switch the engine off and add a small amount of oil and repeat the procedure.

Hope that helps.

15

Thank you for taking the time to find out for me and bother to type it up.

WTF - what was ever wrong with just dipping the oil!!!

 

Shaun

16

Hi,

Did my auto box 2009, 60K miles last year.  worth changing as my oil was very dark.  draining only removes about 2 liters so I changed it twice

Not red but a lot lighter in colour

Graham. 

17

Thanks GB6030 - how did you do it please?