https://en.m.wikipedia.org/wiki/Toyota_model_codes
The numbers/letters preceding the dash describe the body/frame style:
The first digit indicates the motor series (B/F/H/...)
The "J" indicates the vehicle came from the "J" production line.
the 3rd and 4th digits are numeric and indicate the series (25/40/60/...)
The 6th digit (if present) indicates steering position:
The 7th digit (if present) indicates body type
The letters after the dash indicate options etc:
Transmission type
Rear Door Type
Grade/Trim Level
Roof
Aspiration/Fuel
The last letter usually indicates the intended market
If the vehicle was delivered incomplete (usually as a cab and chassis) it received the final designation of "3"
This is of course only applicable to vehicles pre the 1985 unification/standardisation of VIN numbers.
All the Japanese 40 series came from "J" whereas other non-Japanese plants had their own designation i.e. L = Venezuela.
source - cruiserfaq
Regards,
Rodger
Isn't it amazing how a simple question opens up a whole new can of worms!!
Not surprisingly there are a couple of threads on IH8mud about this. There was a bit of debate about the F so someone asked Toyota. This was their reply:
"Thank you for contacting Toyota Motor Sales, U.S.A., Inc.
We appreciate the opportunity to answer your question.
Your FJ Land Cruiser derives its name from the 1950's Toyota Land Cruiser, which arrived in the United States in 1958.
The "F" is a reference to that early 50's engine series type and the "J" refers to the body style of the 1950's 4 Wheel Drive Land Cruiser vehicle.
The third and fourth digits, 40, identifies the generation code for the vehicle's engine, which is the first generation."
This makes sense, as all Toyota vehicles were initially made in Japan but did not get a J suffix on their model code, only the Land Cruiser. Eg. Dyna was U, Hilux was N, Corolla was E preceded by the engine code. There is a Wiki page on this
https://en.m.wikipedia.org/wiki/Toyota_model_codes