DETERMINING WHICH TRANSMISSION YOU HAVE
1. All 88-91 Civic/CRX transmissions are Model L3. Some 91’s are labelled SL3, 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)
C.
12.25 Revolutions = 3.88:1 DX (or ZC)
12.75 Revolutions = 4.05:1 EX (also some 90-91 Civic Si)
13.40 Revolutions = 4.25:1 Si
Anything less than 12.25 Revolutions = HF (three different ratios were available in HF)
