DETERMINING WHICH TRANSMISSION YOU HAVE

1. All 88-91 Civic/CRX transmissions are Model L3. Some 91’s are labelled SL3 (the sticker is on the top), but are still the same transmission.

2. You cannot tell what model of car (Si, DX, HF, LX, EX or even 4-speed STD) the transmission was initially installed in by just looking at the outside of the transmission. The only exception to this is the 88-91 JDM ZC L3 transmission. The splined holes in the differential where the axles are inserted are a larger diameter on the ZC transmission. All other L3’s have the same size smaller splined hole for the axles.

3. You may read at various sites on the Internet that you can tell what model the transmission is by looking at the numbers in the circle by the oil fill plug. You will read something like, “if it says PL3/3000, it is Si” or “if it says PL3/A000, it is DX, etc.” This is not necessarily true! If it says PL3/3000, it could be Si, but it could also be a DX or ZC. These numbers are casting numbers for the back half of the transmission case and are not necessarily an indication of which Final Drive gears are inside.

4. There are two ways to tell which Final Drive gears your transmission has – you can open it up and count the teeth on the gears, or you can use the following procedure:

Transmission Out of Car

A. Shift the transmission into reverse. To do this, take a Phillips screwdriver and insert it through the hole in the shift arm shaft that projects out of the transmission (where the shift linkage connects) and when looking at the end of this shaft, rotate the shaft to the right and push the shaft in. Check to see if it is in reverse by looking at the differential (where the axles go in) while rotating the input shaft. The differential should be turning in the opposite direction from the input shaft.

B. Take a paint pen or marker and place a reference mark at the 12 o’clock position on the differential and another mark at the 12 o’clock position on the input shaft. Rotate the input shaft and count the number of revolutions that the input shaft makes in order to rotate the differential exactly one complete turn. The number of revolutions will tell you which Final Drive you have. (See Chart Below)

Transmission In Car

A. Jack up front driver’s side of car and place a jack stand under it. Shift the transmission into reverse.

B. Take a paint pen or marker and place a reference mark at the 12 o’clock position on the driver’s side tire and another mark at the 12 o’clock position on the crankshaft pulley. Using a socket and ratchet on the crankshaft pulley bolt, rotate the engine counterclockwise and count the number of revolutions that the cranshaft pulley makes in order to rotate the tire exactly one complete turn. The number of revolutions will tell you which Final Drive you have. (See Chart Below)

10.25 Revolutions = HF (Originally sold in California)
11.89 Revolutions = HF (Sold Everywhere but Calif.)
12.25 Revolutions = DX (or ZC)
13.40 Revolutions = Si