rat or ran

[bobtail]

my ford 3.03 transmission no longer has a tag determining rat or ran. is there another way to tell rat from ran? I don't see any markings on the case. is one case larger than the other? mine is 9 3/4 long.

 

[DirtDonk]

The length of the case might be one way, and there might be identifying numbers cast into the case as well. But there may also be a difference in first gear ratios that might clue someone in that knows that kind of stuff.

So along with the measurement you already provided, verify the first gear ratio by shifting it into first and spinning the input shaft by hand, while counting the number of turns of the output shaft.
Seems like there is a 2.99 to 1 ratio, and a 3.20-ish(?) to 1 ratio, and maybe one other.

Good luck.

Paul

 

[Tugross302]

I don’t remember the exact measurements but if you have a TBP catalog look in there. I think it says to measure the adapter between the transmission and transfer case. One is a little longer than the other

 

[.94 OR]

Tom's Catalog:

You can also tell a RAT from a RAN (either was used with the 289 & 302 V8 engines) by measuring the lengths of their adapter housings. The RAT 3-speed transmission uses an 8 7/8" adapter and the RAN transmission uses a 9 3/8" adapter. All 3 transmissions (HEF in 6 cylinder) are stamped with their 3-letter acronym for identification

 

[bobtail]

thanks guys. its a rat