Ok so I found a type r trans im looking to buy. It reads s80 and definatly has a lsd. where the vin plate is supposed to be there are 2 blind holes (holes without threads). Nowhere on the trans does it say lsd. Has no black ink anywhere that i can see. The motor however says R-dot by the engine code. The guy im buying it from claims the engine and trans were stolen and a replacement engine and trans from honda were put in. The engine is a 98 spec usdm type r. Is there anyway of identifiing this trans by the casting numbers at the top of the bell housing? I know about the speed\rpm calculator but Id like to know if this thing is legit before I buy it. Oh and by the way i searched for hours and ive been building hondas for about 15 years now and never seen anything like this.

 

look in the oil seal hole and if you can see through the diff to the other side it is an LSD diff.
if the trans and engine were replacement units, they will not have the green vin plates attached which are mounted with rivets to the blind holes" you describe.
the Black Ink/paint washes off with royal purple or any other degreaser so that cannot be a real identifier.

 

Ok please read what I wrote this one is for the pros. You told me what I already knew.

 

well i dont understand your question then.

it is a S80 LSD tranny that was bought new from Honda.... only could be a ITR tranny. the holes you discribe are legit. thats how a new honda engine/transmission come (along with the RDOT).

 

Im not sure what your exact question is either please clarify, ur post was kinda confusing.

My 97 R had the tranny replaced under factory warrenty and it had no plate/no stamping just as you describe. Wish I could help you out more

 

The holes without threads would indicate to me it could possibly be a JDM trans. A USDM ITR replacement trans (trans purchased from Honda/Acura) would have LSD stamped on it, and no VIN plate. An ITR trans that came stock on an ITR, would not be stamped. Don't know if it's the same for JDM Honda transmissions.

 

my JDM 97R tranny has no stamp, but its also 13yo...

 

Short of taking it apart and inspecting everything or counting teeth, you have already listed every identifier. Externally, LSD stamp, see through differential, and vin tag are the only things to look for.

 

How does one interpolate the casting numbers on top of the bell housing.

 

"Interpolate"? You mean interpret?

My Type R trans has no vin tag, unthreaded holes, and no "LSD" written on it. It came from Japan.

 

Ha that's what happens when you spend too much time on s300

 

Those casting numbers you find on the outside will not help you. They have no relevance to the gearset inside.

 

I'd deff get the R engine too!!!