The Metro has the same transmission as the Suzuki Swift and several other cars made by Suzuki. All of them are more or less a bolt in swap. Usually the only difference is in the shifter rod or shifter brace rod. So if you get a junkyard trans take those two parts as well and you will have no problems.
There are several different speedometer gears for the various tires that have came on the Suzuki Swift, Geo Metro, and 95+ European Subaru Justy. The drive gear inside the transmission is the same number of teeth on all the cars so it does not need to be changed. It is a plastic 18 tooth gear. The only difference is the driven plastic gear. It is the one attached to the speedometer cable and can be removed by taking the single bolt out and gently twisting and pulling it out of the transmission. If it is stuck use penetrating oil to free it up.
The ratios available are:
- 16 tooth brown gear.
It came stock on the Swift GT with 14 inch wheels.
- 17 tooth white gear.
It came stock on all the cars with 13 inch wheels.
- 18 tooth yellow or beige gear.
This was the one to fit the 12 inch wheels.
- Swift GA and Metro Convertible had 165/65R13 tires, the same diameter as the 145/12 tires so had the 18 tooth gear
- Swift GT had 165/65R14 tires, the same diameter as the 155/13 tires so had the 17 tooth gear.
- putting 185/70R14 tires on will require a 16 tooth gear but no cars came stock with it that I know of so it has to be ordered from a dealer.
The part numbers I have so far for the gears are:
- 26131-60B00 Manual Trans 18 tooth
- 26131-64B00 Manual Trans 17 tooth
- 26131-62B00 Automatic 18 tooth
- 26131-62B40 Automatic 17 tooth
I would double check these numbers and make sure to take your gear in and compare them since I have no way to verify these part numbers are accurate.
The final drive ratio does not affect the speedometer gear so if you are changing transmissions no matter what final drive ratio you use it does not change the speedometer readings. Changing tire size is the only reason to change the speedometer gear. The gears are available from a Suzuki dealership if for some reason you can't find one in a junkyard locally.
The transmissions for all the cars are basically the same. The 4wd Swift has some incompatible parts but a majority of the parts are interchangeable. If you want a detailed listing of the first through fifth gear ratios there is a very detailed and updated list on teamswift.net. For this site though we are more interested in fuel economy so the only thing we really care about is the final drive ratio. The numerically lower ratio is almost always better for getting better mileage. The only downside is it will make the car much slower accelerating and not able to climb hills as easy. If you are after the best mileage possible neither of these are a concern though.
The available transmission ratios and what they are out of:
- 3.52:1 1.3L SOHC Swift up to mid year '95
- 3.79:1 98-01 4 cylinder Metro
- 3.85:1 XFi Metro
- 3.95:1 mid year '95 up 1.3L SOHC Swift
- 4.10:1 Swift GT, GTi, 95 and earlier Metro
- 4.39:1 Metro Convertible, 96+ Metro
NOTE: See comment #6 below for some other information. I have no real way to verify either list but it seems Don might have a better list.
So the one to find is the MK2/3 Swift SOHC 1.3L transmission for the best ratio. If you have a 96 up or convertible there is a small gain going to the 89-94 4.10 trans that is very easy to find. I have heard inconsistent reports of what cars had 4.10 and 4.39 gears though so make sure to check the transmissions out before swapping them. To check the ratio open up the gearbox filler plug and count the teeth on the crown wheel, I use a soapstone like is used for welding and when turning the input shaft mark every 10th tooth to keep from losing track. Here is a table of all the gear ratios and how many teeth to count out on the crown wheel.
|Ratio||# of teeth on crown wheel|