My own roadster is an 1990 auto (I commute into London in it) does that need any lubrication changes? (11/99)
Auto's need gearbox oil change more frequently (and equally importantly). AMS do a good synthetic auto transmission fluid - that's what I'd recommend. (11/99)

I've had a member write to me with a problem with his 1994 1.8i automatic roadster.

He writes; 'It does not go into 4th gear until warmed up and it is taking around 8 miles to warm up, the problem is I leave home for work and go straight onto a dual carriageway at 70 mph so the engine is revving at 5000rpm and I only get 4th gear at the end of the carriageway Is there any way of bypassing the sensor that stops it going into 4th so that it will go into 4th when cold. I am averaging 29 mpg at the moment which seems a bit low.' (6/01)
I thought the Auto was a 4 speed with the 4th gear being the overdrive?? Hmmmm maybe I'm wrong but I know it's the case on my 90 Auto and don't think they changed the box on later models. If I'm wrong I would recommend seeing an automatic specialist (not a Mazda dealer as they have little experience with auto's). At least go for a complete fluid/filter/gasket change on the autobox. I ordered the filter and gasket from my local Mazda dealer and they took about a week then got an auto specialist to do the job....which is the best way to go Nothing was wrong with my auto box but since my Ropadster has no service history I am in the process of changing all of my fluids. If the gearbox has gone (e.g teeth broken) then a replacement will be expensive...although I'm sure another Mazda box (from another model) will fit. (6/01)

Hi, I used to be in the autobox trade, some years ago now, but the problem sounds like the early stages of the need for a new/rebuilt box. They used to become slow to engage top because of seal wear. The box on an MX5/Eunosis probably not very clever, (ie late ones are microprocessor controlled), but the top gear is almost certainly just torque converter lock up, be it 4th or 5th, ie it has a small clutch inside. Most true autos do not use "gears" as in a manual box. The problem here is not "chipped gears".

Nor is it likely to be a sensor. I repeat I have not been involved with autos for many years so may be wrong.

Changing the filter and fluid can in some cases cause more trouble than it prevents. The yanks, once the leaders in autos, used to recomend changing the oil every 100,000 miles. In my humble opinion it is waste of time and money, most of the time. But sometimes customers insist and you do as you are asked and charge for it.

IMHO it may be possible to "reseal" this box, this means replacing the rubber/neoprene seals but not the clutch plates or the brake bands. But many auto specialists insist on a full rebuild and wont do "seal jobs"

As for fitting a box from another model, even if the physical external dimensions are the same, unlikley, if it is from a heavier car it may not change gear as and when it should as the valvebody and the govenor are for particular cars.

There is a cheap solution however, if it is seal wear, 1/2 pint of clean thinners can work wonders, just add it to the gearbox fluid. It can work, and it can last for years. OR NOT. At your own risk. (6/01)
As an import I thought I'd change all of the fluids inc . the auto trans fluid. However, having purchased the filter and gasket I now find that all the auto specialist I've contacted say "Don't do it!". They say that the damage that can be caused to the seals etc when doing a fluid change isn't worth risking and that I should just keep it topped up. I know that there aren't many auto 5's out there but I guess some of you will have had other Auto's before. Is this response justified or do you think they don't want this small job ? (6/01)
I used to have an auto until recently and whenever I asked the mechanic I took my car to to check the auto fluid he always said it looked as thought it was in good condition and not to disturb it. My boss is a bit of an auto transmission fan and used to tell me not to change it for the same reasons as the people you spoke to. (6/01)
Hi, as I have said before, leave it alone. (I used to be in the trade.) Not saying yours is but, when an autobox is close to meeting its maker changing the fluid can in fact finish it off sooner than if you had left it alone. (6/01)