Answer
Apr 27, 2025 - 01:31 AM
For the 5-speed manual in your ‘92 Miata, there’s no dipstick. So it’s a simple fill-and-drain plug setup like most manuals from that era.
To check the fluid, you’ll need to get under the car and find the fill plug on the side of the transmission case. It’s usually a 24mm or 23mm bolt about halfway up the passenger side of the gearbox. Make sure the car is level (use jack stands or ramps), and then crack that fill plug open.
If fluid dribbles out, that indicates it's at the right level, which is a good thing. If it’s dry in there, stick your finger in the hole and see if you can feel fluid just below the threads. If it’s low, top it off with GL-4 gear oil (usually 75W-90) until it just starts to spill out of the hole.
Make sure to only remove the fill plug first; you don’t want to drain it and then realize you can’t get the fill plug loose. Thankfully, the manual has this procedure laid out step-by-step with clear images, so you can probably nail this job yourself.
Goodluck!
