The problem with Miatas is that the odometer memory is actually held in the electronic gauge itself. Therefore, if it needs to be replaced, the number will be the mileage as on the new odometer - 0. Or if you purchase a used odometer, it will display that mileage, not your original.
My advice is that you purchase a used odometer, and that includes the whole gauge cluster (speedometer, tachometer, etc). I would recommend used because:
Replacing the cluster is very easy, and only takes a gentle hand. It is literally held in with 3 plugs, other than the cover that is simply pulled off. Please review the Related Links section for additional details regarding instrument cluster removal.
If your odometer/speedometer stopped working, then you must replace the "vehicle speed sensor" located on top of the differential if your have a manual transmission.
You do not repair the relay. It will be best to replace them with know good ones.
There is no scheduled mileage or time mentioned in any manual for Timing Chain replacement.
It is the odometer in kilometers, the first is in miles.
The timing chain has no set date or mileage for replacment. It will normally last the life of the engine.
Use SAE 10w30 conventional or synthetic. Use a High Mileage oil if the odometer reads over 100,000 miles.
See if your public library has a Chilton's for your car to replace the clutch.
You must replace the assembly/ or the entire door unit
The average gas mileage of a Mazda 3 Sport depends on the engine and body style it has. Most Mazda 3 Sports have an average gas mileage between 25-30 MPG.
Worm gear is broken. Easy fix just replace worm gear .
no it will not reset..
This is a major repair that is too complicated to be discussed here in this space. You can buy a Chilton's repair manual if you wish to tackle this yourself but know that it takes knowledge and the proper tools to make this repair. This is not a repair for a novice.